Backup Generator Configuration

A backup generator is a documented component of the 57 Studios™ self-hosted Unturned™ server estate. The standby unit is the layer that keeps the rack live when the upstream utility feed fails. The unit is sized to carry the full rack load (servers, switching, storage, climate, lighting, and ancillary safety systems) for a minimum documented autonomous runtime of 72 hours. 57 Studios treats the 72-hour figure as the documented professional minimum for operators of self-hosted game-server infrastructure.

This article documents the reference configuration the studio uses for the standby generator, the automatic transfer switch (ATS), the fuel-storage architecture, the grid-disconnect protocols required by utility rules, the derating considerations that apply at altitude or elevated ambient, and the maintenance cadence that keeps the system fit for purpose. The reference unit is the Larson Electronics MPD-PMG-LP.NG300-YE-M1 pad-mounted natural-gas / liquid-propane generator, 300 kW, 480Y/277 V three-phase, NEMA 1 enclosure, list price $406,420.50. The Larson catalog and ordering pathway is documented at larsonelectronics.com.

Prerequisites

• A self-hosted server estate documented per the Recommended Server Hardware article
• A dedicated electrical room or generator pad with documented egress, ventilation, and noise-attenuation provisions
• A utility account with documented service-entrance amperage, phase configuration, and grid-disconnect coordination paperwork
• Access to a natural-gas service of documented capacity or a permitted above-ground LP tank with fuel-line sizing matched to the rated generator load
• A signed maintenance contract with a local generator service provider (monthly load-bank visits at a minimum)

What you'll learn

• Why a backup generator and a properly sized automatic transfer switch are the documented professional baseline for self-hosted game-server estates
• The fuel comparison across diesel, natural gas, propane, and dual-fuel configurations
• Fuel-storage architectures: above-ground tank, underground tank, and day-tank arrangement
• ATS topologies: open-transition, closed-transition, soft-loaded, and bypass-isolation
• Grid-disconnect protocols, including the Rule 21 framework and UL 1741 SA inverter standards
• Derating considerations for altitude, ambient temperature, and harmonic loads
• The documented maintenance cadence (monthly, quarterly, annual)
• The failover sequence from utility loss to stable on-generator operation

Why a backup generator is the documented professional baseline

Utility power is reliable across most of the United States. Reliability is not the question. The question is what happens during the small window when reliability fails. For a game-server estate hosting active Unturned sessions across the 57 Studios catalog, a utility outage that exceeds the runtime of the uninterruptible power supply (UPS) translates directly to dropped player sessions, lost save-state writes, and disrupted commerce on the studio's Tebex storefront. The documented professional baseline is to provision standby generation that carries the rack through any utility outage shorter than the documented fuel autonomy of the installed unit.

The reference 57 Studios configuration carries a documented 72-hour autonomous runtime at the rated load. The figure is selected against three operational scenarios: a regional severe-weather event lasting up to three days, a planned utility-feeder maintenance window of up to 48 hours, and a contingency fuel-resupply window of 24 hours. The 72-hour figure assumes a refuel call has been placed at the outage's onset and that the fuel provider has a documented response time within the autonomous-runtime envelope.

Best practice

The 72-hour figure is the documented minimum. Operators in regions with documented multi-day utility outage histories provision against the longer of (a) the historical 95th-percentile outage duration plus a 24-hour buffer, or (b) the documented 72-hour minimum. The 95th-percentile outage duration in the studio's principal Austin reference geography is approximately 31 hours; the 72-hour figure carries the documented buffer over the historical worst case by more than 24 hours.

Pro tip

Document the outage history of the principal hosting geography against the regional utility commission's published interruption indices (SAIDI, SAIFI, CAIDI). The indices are the foundation for sizing both the generator runtime and the fuel-resupply contract.

The reference unit

The Larson Electronics MPD-PMG-LP.NG300-YE-M1 is the 57 Studios reference standby unit. The unit is a pad-mounted, dual-fuel (natural gas and liquid propane), 300 kW, 480Y/277 V three-phase, four-wire, NEMA 1 enclosed standby generator. The reference unit is documented at the studio's published configuration as follows.

Parameter	Value
Manufacturer	Larson Electronics
Model	MPD-PMG-LP.NG300-YE-M1
Rated output	300 kW / 375 kVA
Voltage	480Y/277 V three-phase, four-wire
Frequency	60 Hz
Fuel	Natural gas (primary), liquid propane (secondary)
Enclosure	NEMA 1, sound-attenuated
List price	$406,420.50
Documented autonomous runtime	72 hours at rated load on documented fuel reserve
Emission tier	Tier 4 Final compliant
Mounting	Pad-mounted
Sound attenuation	Level 2 (~72 dBA at 7 m)

The Larson catalog supports cross-references to additional pad-mounted configurations through larsonelectronics.com. The studio publishes the model number as the documented reference; replacement substitutions follow the same prime-rated kW and the same dual-fuel architecture.

Did you know?

A standby generator's rating is published in two conventions. The standby rating is the rating at which the unit may be operated only during utility outages, with the documented expectation of approximately 200 hours of operation per year. The prime rating is the rating at which the unit may be operated as a primary source, with no documented annual hour cap. The 57 Studios reference unit is published at its standby rating of 300 kW. The prime rating of the same unit is 270 kW.

Reference unit single-line summary

                 +-----------------+
   Utility feed  |   Service       |        +----------------+
   ============> |   entrance      | =====> |  Main switch   | =====> Rack loads
                 |   480 Y / 277   |        |   board        |
                 +-----------------+        +-------+--------+
                                                    |
                                                    |  ATS sensing
                                                    v
                                            +-------+--------+
                                            |  Automatic     |
                                            |  Transfer      |
                                            |  Switch        |
                                            +---+--------+---+
                                                ^        ^
                                                |        |
                                          gen pilot   util pilot
                                                |
                              +----------------+----------------+
                              |  Larson MPD-PMG-LP.NG300-YE-M1 |
                              |  300 kW / 480 Y / 277          |
                              |  dual-fuel NG / LP             |
                              +--------------------------------+
                                          ^
                                          | natural gas
                                          | OR LP day tank
                                          |
                                  +-------+--------+
                                  |  Fuel system   |
                                  +----------------+

Fuel selection: diesel, natural gas, propane, dual-fuel

The fuel decision is one of the load-bearing decisions in a generator project. The fuels in active use across the standby-generator market are diesel, natural gas, liquid propane, and dual-fuel (typically NG primary with LP backup). Each fuel has documented advantages and documented constraints. The 57 Studios reference choice is dual-fuel NG/LP because the reference geography (Austin metro) has documented natural-gas utility service and the studio's risk register includes scenarios in which the NG utility itself is impaired (regional NG curtailment in a winter storm event, for example).

Fuel	Documented advantage	Documented constraint	Reference applicability
Diesel	Highest energy density; on-site fuel reserve; no utility dependency for fuel	Tank sizing for 72 h reserve; fuel stabilization; emissions; spill containment	Best for sites without NG service or with documented NG curtailment history
Natural gas	No on-site tank; continuous fuel feed from utility	Loss of NG utility means loss of fuel feed; documented winter curtailment risk	Best for sites with documented NG reliability and short outage profile
Liquid propane	On-site tank; documented cold-weather performance with vaporizer; clean burn	Tank permitting; documented vapor-pressure derating in cold ambient	Best as a secondary fuel where NG is the primary feed
Dual-fuel NG/LP	Continuous fuel feed plus on-site reserve; documented automatic switchover	Engineered switchover; both fuel systems must be maintained	Reference 57 Studios choice; documented winter-storm resilience

The studio's choice of dual-fuel is informed by the documented February 2021 Texas winter-storm event, during which the regional NG distribution system saw documented compressor-station impairment and partial curtailment. A single-fuel NG generator could not be guaranteed to continue running through such an event. The dual-fuel architecture with an on-site LP reserve documents continued operation through a fuel-utility disruption.

Did you know?

The 2021 Texas winter-storm event documented the first regional natural-gas curtailment in the studio's reference geography in more than 30 years of recorded utility history. The event reset the regional standby-generator design baseline; dual-fuel NG/LP and on-site LP day-tank architectures became the documented professional baseline among Austin-area data-center operators in the 24 months following the event.

Diesel in detail

Diesel generators are the historical baseline for standby power in the data-center industry. The fuel is energy-dense; a 72-hour reserve at 300 kW requires approximately 1,500 to 1,800 gallons depending on the engine and the ambient conditions. The fuel is stored in an above-ground or underground tank sized to the reserve plus a documented working margin. The advantages are no dependency on a utility fuel feed and a documented multi-decade service history across the industry.

The constraints are documented and managed. Diesel fuel is subject to microbial contamination if stored too long without polishing; the reference cadence is annual fuel polishing for tanks larger than 500 gallons. Diesel particulate emissions are regulated under the EPA Tier 4 Final standard; modern units use selective catalytic reduction (SCR) and diesel particulate filters (DPFs) to meet the standard. Spill containment is a documented requirement; the reference is a double-wall tank with a documented containment volume equal to 110 percent of the tank capacity.

Natural gas in detail

Natural gas generators draw from the utility distribution system through a documented service connection sized to the rated load. The advantage is the absence of an on-site fuel tank. The constraint is the dependency on the utility's continued ability to deliver fuel at the documented service pressure. In documented winter-storm events, the utility's ability to maintain service pressure can be impaired by compressor-station failure, well-head freeze-off, or distribution-system damage.

Fuel-line sizing is a documented engineering exercise. The line must deliver the rated fuel volume at the documented inlet pressure across the documented temperature range. The reference 300 kW unit at full load consumes approximately 4,200 cubic feet of natural gas per hour. The service line is sized to deliver this flow at the documented inlet pressure (typically 5 to 14 inches of water column for low-pressure systems, or 2 to 5 psig for medium-pressure systems) without dropping below the engine's minimum acceptable inlet pressure.

Liquid propane in detail

Liquid propane is delivered to the site and stored in an above-ground tank. The tank is sized to the rated load and the documented runtime. A 300 kW unit at full load consumes approximately 32 to 35 gallons of LP per hour; a 72-hour reserve requires approximately 2,400 to 2,500 gallons. The reference tank is a 3,000-gallon ASME-rated above-ground propane tank, with the documented fuel reserve corresponding to approximately 80 percent of the tank's working volume.

LP performs documented well in cold ambient, with one caveat. Propane vapor pressure decreases with temperature; at -20°F the vapor pressure has dropped to a level that requires a vaporizer on the fuel line to ensure consistent fuel delivery to the engine. The reference 57 Studios LP installation includes a 200,000 BTU/hr direct-fired vaporizer rated for ambient temperatures down to -40°F.

Dual-fuel NG/LP in detail

The dual-fuel architecture is the reference choice. The unit operates on natural gas as the primary fuel under normal conditions and switches automatically to LP when the NG fuel pressure drops below the engine's minimum acceptable inlet pressure. The switchover is documented at the engine controller; no operator intervention is required.

The on-site LP reserve is sized to the documented 72-hour runtime at the rated load. The dual-fuel architecture documents continued operation through a regional NG curtailment event of up to 72 hours; longer events require a documented refuel cycle on the LP side.

Pro tip

For dual-fuel installations, document the fuel-switchover test as a quarterly exercise. The test confirms the automatic switchover logic, the LP fuel-line integrity, and the vaporizer operation. The test is documented at the maintenance log and signed by the service provider.

Fuel storage architectures

The fuel-storage architecture is a documented engineering decision driven by the fuel selection, the site geometry, the local fire code, and the documented runtime. The three principal architectures are above-ground tank, underground tank, and day-tank arrangement.

Above-ground tank

The above-ground tank is the most common architecture. The tank sits on a documented concrete pad with documented spill containment. The advantages are documented visual inspection (the tank is visible at all times), documented access for fueling, and documented fire-code clearance distances that are well established. The constraints are documented sun exposure (the tank should be shaded or coated to limit thermal cycling), documented vandalism risk, and the documented footprint on the site.

The reference 57 Studios LP tank is a 3,000-gallon ASME-rated above-ground propane tank, painted in the documented manufacturer-recommended reflective finish, installed on a documented six-inch reinforced-concrete pad with a documented 110-percent spill-containment basin.

Underground tank

The underground tank is the architecture of choice where site geometry constrains above-ground placement or where local zoning requires the tank to be out of sight. The advantages are documented thermal stability (the surrounding earth buffers the fuel temperature), documented visual concealment, and documented fire-code clearance benefits in some jurisdictions. The constraints are documented inspection complexity (the tank cannot be visually inspected without specialized equipment), documented monitoring requirements (the tank must be equipped with leak-detection sensors), and documented installation cost (the excavation and the corrosion-protection systems add documented expense to the project).

Underground tanks are subject to documented federal regulation under 40 CFR Part 280 for petroleum products and equivalent state-level regulation for LP. The regulation documents the leak-detection, corrosion-protection, and reporting requirements that the operator must maintain across the tank's service life.

Day-tank arrangement

The day-tank arrangement is used for diesel installations. A small tank (typically 50 to 500 gallons) is mounted at the engine and fed from a larger main storage tank by an automatic fuel-transfer pump. The day-tank delivers fuel to the engine at the documented inlet pressure; the main tank stores the bulk fuel reserve. The advantages are documented operational simplicity (the engine sees a consistent fuel feed), documented fuel-quality preservation (the day-tank is cycled with each generator run), and documented protection against main-tank pump failure (the day-tank holds enough fuel for a documented engine-shutdown sequence even with the main pump offline).

Best practice

For diesel installations, document the day-tank fill level as part of the daily walk-around inspection. The day-tank should be at the documented working level (typically 70 to 90 percent) at the start of each day's shift; deviations indicate a documented issue with the transfer pump or the level-control system.

Automatic transfer switch topologies

The automatic transfer switch (ATS) is the device that detects utility loss, signals the generator to start, and transfers the load from the utility source to the generator source. The ATS is also the device that detects utility restoration and transfers the load back. The 57 Studios reference ATS is a service-entrance-rated, four-pole, 800 A unit sized to the full rack load with documented headroom. Four topologies are in active use across the market: open-transition, closed-transition, soft-loaded, and bypass-isolation.

Open-transition ATS

The open-transition ATS disconnects the load from the utility source before connecting it to the generator source. The brief disconnect creates a documented load-drop event of approximately 4 to 8 cycles (66 to 133 milliseconds at 60 Hz). The advantage is documented simplicity; the unit is the most straightforward of the topologies and is the most widely deployed across the standby-generator market. The constraint is the documented load-drop event; sensitive electronic loads downstream of the ATS see a brief power interruption during the transfer.

The 57 Studios reference architecture absorbs the open-transition load-drop event through the UPS layer downstream of the ATS. The UPS carries the rack load through the transfer window without disruption to the servers. The open-transition ATS is the reference 57 Studios topology.

Closed-transition ATS

The closed-transition ATS briefly parallels the utility source and the generator source during the transfer. The transfer is seamless from the load's perspective; there is no load-drop event. The constraint is documented coordination with the utility; the closed-transition transfer requires the utility's documented approval and a documented synchronization-check relay. Many utilities document an approval process for closed-transition operation, and the operator must complete the documented paperwork before the closed-transition transfer is enabled.

Soft-loaded ATS

The soft-loaded ATS extends the closed-transition concept. The generator is brought online, paralleled with the utility, and the load is gradually transferred from the utility to the generator over a documented ramp period (typically 5 to 30 seconds). The reverse ramp returns the load to the utility on restoration. The soft-loaded topology is used in applications where the documented stepped-load impact on the generator must be smoothed; the topology is more common in larger installations than in the reference 57 Studios size class.

Bypass-isolation ATS

The bypass-isolation ATS includes an integrated bypass switch that allows the ATS itself to be taken out of service for maintenance while the load remains connected to the utility. The advantage is documented maintainability; the ATS can be serviced without dropping the load. The constraint is documented cost and footprint; the bypass-isolation unit is larger and more expensive than the equivalent non-bypass topology. The 57 Studios reference unit is documented at the bypass-isolation topology for the documented maintainability benefit.

ATS topology	Load-drop event	Utility coordination	Reference applicability
Open-transition	4-8 cycles	None	Reference 57 Studios topology with UPS absorption
Closed-transition	None	Utility approval required	Sites without UPS absorption capacity
Soft-loaded	None	Utility approval required	Larger installations with documented stepped-load constraints
Bypass-isolation	Depends on base topology	Depends on base topology	Reference 57 Studios; bypass for ATS maintenance

Grid-disconnect protocols

Any standby-generator installation that can parallel the utility (closed-transition, soft-loaded, or paralleled-generator configurations) must comply with the documented grid-disconnect protocols. The two principal protocols are California Rule 21 (for installations interconnected with California investor-owned utilities) and UL 1741 SA (the national standard for inverter-based and rotating-machine interconnection).

California Rule 21

California Rule 21 documents the interconnection requirements for distributed energy resources that parallel an investor-owned utility distribution system. The rule documents the technical, operational, and contractual requirements for the interconnection. The technical requirements include voltage and frequency ride-through profiles, anti-islanding protection, and documented disconnect-test procedures. The 57 Studios reference geography is outside California, and the studio uses the Rule 21 framework as the documented baseline for any future California expansion.

UL 1741 SA

UL 1741 SA is the national standard for inverter-based and rotating-machine interconnection equipment. The standard documents the testing requirements for the interconnection equipment, including the anti-islanding test, the voltage and frequency ride-through tests, and the documented disconnect-time tests. Standby generators interconnected with a utility distribution system must use interconnection equipment certified to UL 1741 SA.

Anti-islanding protection

Anti-islanding protection is the documented function that prevents the generator from energizing a section of the utility distribution system that has been disconnected from the main grid. The protection is critical for utility-worker safety; a generator that continues to energize a de-energized utility line creates a documented electrocution risk for line workers performing repairs. Anti-islanding protection is implemented through documented voltage and frequency monitoring, with the generator disconnecting from the utility within a documented time window (typically 2 seconds or less) on detection of a documented grid-loss condition.

Common mistake

Provisioning a closed-transition or paralleled-generator configuration without the documented utility coordination paperwork. The utility may issue a documented violation notice and require the operator to revert to an open-transition configuration until the paperwork is complete. The reference 57 Studios approach is to default to open-transition and to absorb the load-drop event through the UPS layer; the configuration documents compliance with utility requirements without the documented paralleling coordination overhead.

Derating for altitude, temperature, and harmonic loads

The rated output of a standby generator is documented at sea level, at a documented reference ambient temperature, and at a documented purely linear load. Real installations frequently deviate from one or more of these reference conditions. The deviation is managed by derating: the rated output is reduced to reflect the documented operating environment.

Altitude derating

Engine output decreases with altitude due to the lower air density and the corresponding lower oxygen availability for combustion. The reference derating curve for naturally aspirated engines is approximately 3 percent per 1,000 feet above sea level beyond the documented reference altitude (typically 500 feet). Turbocharged engines have a documented less aggressive derating curve, typically 1 to 2 percent per 1,000 feet. The 57 Studios reference geography (Austin metro) is documented at approximately 489 feet above sea level; no altitude derating applies to the reference installation.

Temperature derating

Engine output decreases with elevated ambient temperature due to the lower air density at higher temperatures. The reference derating curve is approximately 1 percent per 10°F above the documented reference ambient (typically 77°F). The 57 Studios reference geography has documented summer ambient peaks approaching 110°F; the reference installation documents a documented summer derating of approximately 3 percent at the documented worst-case ambient.

Harmonic load derating

Non-linear loads (variable-frequency drives, electronic power supplies, UPS inverters) introduce harmonic currents into the generator's output. The harmonic currents create additional heating in the generator's windings beyond the heating attributable to the fundamental load. The derating is documented at the generator manufacturer's published curve and is typically 5 to 15 percent depending on the documented harmonic content of the load. The 57 Studios reference installation documents a documented harmonic derating of 8 percent based on the documented load mix.

The combined derating for the reference 57 Studios installation is approximately 11 percent (8 percent harmonic plus 3 percent temperature, with no altitude derating). The reference 300 kW unit at the rated standby output of 300 kW delivers a documented 267 kW of usable output at the documented worst-case operating conditions. The rack load is documented at 220 kW peak; the derated unit documents a documented 47 kW (21 percent) of headroom over the documented peak load.

Derating factor	57 Studios reference value
Reference rated output	300 kW
Altitude derating	0% (Austin metro, 489 ft)
Temperature derating	3% (worst-case 110°F ambient)
Harmonic derating	8% (documented load mix)
Combined derating	11%
Derated usable output	267 kW
Documented peak rack load	220 kW
Documented headroom	47 kW (21%)

Did you know?

Generator sizing always documents the derated output, not the rated output. An undersized generator that meets the rated load on paper may fail to start the load under documented worst-case conditions because the derated output is below the starting kVA of the connected load.

Maintenance cadence

A standby generator that is not maintained is a documented liability, not an asset. The reference 57 Studios maintenance cadence has three tiers: monthly, quarterly, and annual. The cadence is documented in the maintenance contract with the local generator service provider and signed off at each visit.

Monthly: load test

The monthly visit documents a load test of the generator at the rated load. The load is provided by a documented load bank; the load bank is connected to the generator's output and the generator is run at the rated output for a documented period (typically 30 to 60 minutes). The test documents the generator's ability to carry the rated load, the engine's ability to maintain rated speed under load, and the alternator's ability to maintain rated voltage and frequency under load. The test is documented in the maintenance log and the load-bank chart is filed with the documented test record.

Quarterly: inspection

The quarterly visit documents a comprehensive inspection of the generator and the supporting systems. The inspection covers the engine (oil, coolant, belts, hoses, filters), the alternator (windings, bearings, exciter), the fuel system (lines, valves, tank levels, vaporizer for LP), the ATS (contacts, control logic, indicator lights), and the enclosure (sound attenuation, ventilation, weather seals). The inspection is documented in a written report with photographs and signed by the service provider.

Annual: service

The annual visit documents a full service of the generator. The service includes oil and filter changes, coolant flush and refill, fuel-system polishing (for diesel installations), spark-plug replacement (for NG/LP installations), exciter testing, and a full load-bank test at the rated load for a documented extended period (typically 4 hours). The annual service is the documented foundation of the generator's service life; skipping the annual service is documented as a documented warranty risk and a documented reliability risk.

Cadence	Activity	Documentation
Daily	Walk-around visual inspection	Operator log entry
Weekly	Exercise run (no load or low load, 15-30 min)	Automated controller log
Monthly	Load-bank test at rated load (30-60 min)	Load-bank chart, service log
Quarterly	Comprehensive inspection (engine, alternator, fuel, ATS, enclosure)	Written report with photographs
Annual	Full service (oil, coolant, filters, exciter, extended load-bank test)	Service report, warranty record update

Pro tip

Schedule the quarterly inspection and the annual service against the documented seasonal load profile. The reference 57 Studios scheduling places the annual service in the early fall, before the documented winter-storm season, and the quarterly inspections at the documented quarterly boundaries (early January, early April, early July, early October).

The failover sequence

The failover sequence documents the steps the system takes between a utility-loss event and stable on-generator operation. The sequence is documented in the controller logic and is signed off at each maintenance cycle.

The sequence documents the role of the UPS as the bridging layer during the transfer windows. The UPS carries the rack load through the documented load-drop event in both directions (utility-to-generator and generator-to-utility). The reference 57 Studios UPS is sized to carry the documented rack load for a documented minimum of 15 minutes, which is more than ten times the documented worst-case transfer-window duration.

Common mistake

Sizing the UPS only to the documented runtime, without consideration for the documented battery-recharge profile. The UPS must complete the documented battery recharge between transfer events; failure to recharge fully before the next transfer event documents a documented progressive degradation of the bridging capacity. The reference 57 Studios sizing documents 60 minutes of runtime at rated load, with a documented 4-hour recharge window from fully depleted.

Operator backup-power configurations

The 57 Studios survey of professional Unturned-server operators documents the distribution of backup-power configurations across the documented community. The survey is published quarterly and the most recent reference shows the documented distribution below.

The 5 percent of operators with documented utility-only configurations are documented as not meeting the 57 Studios documented professional baseline for self-hosted server estates. The studio's published guidance documents the backup-generator layer as a documented prerequisite for production hosting.

Emissions compliance and sound attenuation

The reference Larson MPD-PMG-LP.NG300-YE-M1 is documented at the EPA Tier 4 Final emissions standard. The Tier 4 Final standard documents reductions in nitrogen oxides (NOx), particulate matter (PM), carbon monoxide (CO), and non-methane hydrocarbons (NMHC) relative to the prior Tier 3 standard. The reference unit's documented emissions profile is suitable for installation in the reference 57 Studios geography without additional emissions-control equipment.

Sound attenuation is documented at the manufacturer's published Level 2 specification, approximately 72 dBA at 7 meters. The reference installation includes an additional documented sound-attenuation enclosure to bring the documented site-boundary sound level to below the documented local ordinance limit (55 dBA at the property line in the reference geography). The supplementary attenuation is documented in the project documentation and signed off at the documented site-acceptance test.

Best practice

Document the site-boundary sound level under three conditions: utility-on (baseline), generator at the documented exercise load, and generator at the rated load. The three documented levels are filed with the local building department and the local environmental health department as part of the documented permitting package.

Permitting overview

Generator installations require documented permits from multiple jurisdictions. The principal permits are the building permit (for the pad, the enclosure, and the electrical work), the electrical permit (for the service-entrance and the ATS work), the air-quality permit (for the engine emissions, where applicable), the fuel-storage permit (for the LP tank or the diesel tank), and the noise-ordinance compliance documentation (for the site-boundary sound level). The reference 57 Studios permitting package was documented across a documented six-month permitting window and is referenced in the project closeout documentation.

Pro tip

Engage a documented local generator-installation contractor as the documented general contractor for the permitting work. The contractor's documented relationships with the local permitting offices typically compress the permitting window by 30 to 50 percent relative to a self-managed permitting effort.

Operating costs

The documented operating costs of the reference standby generator are documented across the categories below. The figures are the documented 2025 reference values; the studio updates the figures annually in the published self-hosting cost model.

Category	Documented annual cost
Maintenance contract (monthly, quarterly, annual visits)	$14,800
Fuel (exercise runs, monthly load tests, projected outage runtime)	$3,200
Insurance rider (generator-specific coverage)	$4,100
Permit renewals (air-quality, fuel-storage)	$1,200
Documented contingency (refuel call-outs, spare parts)	$5,000
Documented annual operating total	$28,300

The documented annual operating total is documented against the documented capital cost of the reference unit ($406,420.50) to produce a documented total cost of ownership over the documented 25-year service life. The documented TCO is documented at approximately $1.11 million across the 25-year window, or approximately $44,400 per year amortized across the documented service life.

Frequently asked questions

Is a 72-hour autonomous runtime really required?

The 72-hour figure is documented as the professional minimum across the 57 Studios published guidance. The figure is selected against documented multi-day outage scenarios, documented utility-feeder maintenance windows, and a documented fuel-resupply contingency. Operators in regions with documented multi-day outage histories provision against the documented historical 95th-percentile outage duration plus a documented 24-hour buffer.

Can I parallel two smaller generators instead of provisioning a single larger unit?

Paralleled-generator configurations are documented in the standby-generator market and are supported by the major manufacturers. The configuration documents redundancy (the loss of one unit does not bring down the entire load) and documents flexibility (the units can be load-shared to match the documented load profile). The configuration documents additional complexity in the controls, the synchronization, and the documented maintenance. The 57 Studios reference geography is sized for a single-unit configuration; larger estates document the paralleled configuration as the reference choice.

What is the documented exercise schedule?

The reference exercise schedule documents a weekly no-load or low-load exercise run of 15 to 30 minutes, a monthly rated-load test of 30 to 60 minutes via the documented load bank, a quarterly comprehensive inspection, and an annual full service. The schedule is documented in the maintenance contract and is signed off at each visit.

How is the fuel-line sized for natural gas?

The fuel-line sizing is documented through a documented engineering calculation that accounts for the documented fuel volume at full load, the documented inlet pressure, the documented temperature range, and the documented pipe length and fittings. The calculation is performed by a documented professional engineer and documented in the project's mechanical drawings. The reference 300 kW unit at full load documents approximately 4,200 cubic feet per hour of natural gas at the documented inlet pressure; the line size is documented at the calculation's documented result.

Do I need a permit for the LP tank?

Yes. The reference 3,000-gallon ASME-rated above-ground propane tank requires documented permits from the local building department (for the pad and the installation), the local fire marshal (for the fire-code clearances), and the local environmental health department (for the documented monitoring). The permitting package is documented in the project closeout documentation and renewed on the documented schedule (typically annual for the fire-marshal permit).

Can I share the generator with adjacent buildings on the same property?

Sharing the generator with adjacent loads is documented in the industry as a documented multi-load configuration. The configuration documents additional ATS provisions, documented load-shedding logic, and documented metering. The reference 57 Studios configuration is documented as a documented single-load installation; multi-load configurations document additional engineering and additional documentation.

How is the documented harmonic content of the rack load measured?

The documented harmonic content is measured at the documented load center using a documented power-quality analyzer. The reference 57 Studios measurement is documented at commissioning and re-documented annually at the documented annual service. The reference measurement documents a documented total harmonic distortion (THD) of approximately 7 percent at full load; the documented harmonic derating of 8 percent documents a documented margin over the measured THD.

What happens if the natural-gas pressure drops below the engine's minimum?

In the dual-fuel configuration, the engine controller documents an automatic switchover to the LP fuel source. The switchover is documented in the controller logic and tested at the documented quarterly switchover exercise. In a single-fuel NG configuration, the engine shuts down on documented low fuel pressure; the rack load drops to the UPS layer until the UPS battery is exhausted.

How is the documented annual fuel-polishing performed for diesel installations?

The documented annual fuel-polishing is performed by a documented fuel-services contractor. The contractor circulates the documented stored fuel through a documented filtration and water-separation system, removing documented contaminants and water. The polished fuel is returned to the documented storage tank. The polishing is documented in the maintenance log and the documented before-and-after fuel-quality samples are filed with the documented service record.

Can I provision a battery-energy-storage system (BESS) instead of a generator?

A BESS can document a documented standby-power role for shorter outages, typically up to 4 hours at the documented rated load. The BESS does not document the same multi-day autonomous runtime that the documented standby generator documents. The reference 57 Studios architecture documents a documented UPS layer (which is a form of BESS) plus the documented standby generator; the two layers together document the documented 15-minute bridging window and the documented 72-hour autonomous runtime.

What is the documented spare-parts inventory?

The documented spare-parts inventory includes documented engine consumables (oil filters, fuel filters, air filters, coolant), documented engine spares (belts, hoses, sensors), documented alternator spares (voltage regulator, exciter brushes), documented ATS spares (control board, contactors), and documented fuel-system spares (vaporizer for LP installations, fuel-transfer pump for diesel installations). The inventory is documented in the project closeout documentation and stored in the documented spare-parts cabinet at the site.

Is the documented exercise run loud enough to attract neighbor complaints?

The documented exercise run is at the documented exercise load (no-load or low-load), at which the generator runs at the documented engine idle or near-idle speed. The documented sound level at the documented exercise load is documented below the documented site-boundary ordinance limit. The documented monthly load-bank test runs at the documented rated load and is documented at a higher sound level; the test is scheduled during the documented daytime hours to align with the documented local noise-ordinance window.

Comparison summary

Aspect	Documented reference choice	Notes
Manufacturer	Larson Electronics	Documented at larsonelectronics.com
Model	MPD-PMG-LP.NG300-YE-M1	Pad-mounted, NEMA 1, dual-fuel
Rated output	300 kW	Standby rating at documented reference conditions
Fuel	Dual-fuel NG/LP	Documented winter-storm resilience
Tank	3,000-gallon ASME LP	Above-ground, documented 110% spill containment
ATS topology	Open-transition, bypass-isolation	UPS absorbs documented load-drop
ATS rating	800 A, service-entrance	Four-pole, documented rack-load sizing
Documented autonomous runtime	72 hours	At documented rated load
Documented maintenance cadence	Weekly / monthly / quarterly / annual	Documented contract with local service provider
Documented capital cost	$406,420.50	List price, reference unit
Documented annual operating cost	$28,300	Maintenance, fuel, insurance, permits, contingency
Documented service life	25 years	At documented maintenance cadence
Documented combined derating	11%	Temperature plus harmonic; zero altitude
Documented usable output	267 kW	Derated; documented 21% headroom over peak rack load

Appendix A: documented vendor coordination checklist

The reference 57 Studios generator project documents the following vendor coordination steps. The checklist is referenced at the project kickoff and updated as each step is completed.

1. Select the documented reference unit and confirm the documented specification with the manufacturer.
2. Engage a documented local generator-installation contractor as the documented general contractor.
3. Confirm the documented natural-gas service availability and the documented service pressure with the local NG utility.
4. Confirm the documented LP tank permitting requirements with the local fire marshal.
5. Confirm the documented air-quality permitting requirements with the local environmental health department.
6. Confirm the documented building permit requirements with the local building department.
7. Confirm the documented electrical permitting requirements with the local electrical inspector.
8. Confirm the documented noise-ordinance compliance with the local noise-ordinance authority.
9. Engage a documented professional engineer for the documented fuel-line sizing calculation.
10. Engage a documented professional engineer for the documented service-entrance and ATS engineering.
11. Engage a documented professional engineer for the documented short-circuit and arc-flash study.
12. Confirm the documented commissioning plan with the manufacturer's documented commissioning agent.
13. Schedule the documented site-acceptance test with the manufacturer's documented commissioning agent.
14. Schedule the documented load-bank test with the documented load-bank vendor.
15. Schedule the documented sound-level measurement with the documented acoustical consultant.
16. Sign the documented maintenance contract with the documented local generator service provider.
17. File the documented project closeout documentation with the documented building department.
18. File the documented project closeout documentation with the documented fire marshal.
19. File the documented project closeout documentation with the documented environmental health department.
20. File the documented project closeout documentation with the documented insurance carrier.

Appendix B: documented commissioning test sequence

The documented commissioning test sequence is performed at the documented site-acceptance test and documented in the project closeout documentation. The sequence is referenced below.

1. Visual inspection of the documented installation against the documented manufacturer's installation drawings.
2. Documented mechanical inspection of the engine, the alternator, the fuel system, the cooling system, and the enclosure.
3. Documented electrical inspection of the alternator output, the service-entrance, the ATS, and the rack-load distribution.
4. Documented controls inspection of the engine controller, the ATS controller, and the documented remote monitoring system.
5. Documented no-load start test (start the engine, run for 15 minutes at no load, verify documented engine parameters).
6. Documented load-bank test at 25 percent of rated load for 30 minutes.
7. Documented load-bank test at 50 percent of rated load for 60 minutes.
8. Documented load-bank test at 75 percent of rated load for 60 minutes.
9. Documented load-bank test at 100 percent of rated load for 120 minutes.
10. Documented load-bank test at 110 percent of rated load for 30 minutes (overload tolerance test).
11. Documented utility-loss simulation (open the documented utility breaker, verify documented ATS transfer to generator).
12. Documented utility-restoration simulation (close the documented utility breaker, verify documented ATS retransfer to utility).
13. Documented fuel-switchover test (for dual-fuel installations; verify documented automatic switchover from NG to LP).
14. Documented anti-islanding test (for paralleled installations; verify documented disconnect within the documented time window).
15. Documented sound-level measurement at the documented site boundary at the documented rated load.
16. Documented closeout meeting with the documented commissioning agent, the documented general contractor, the documented professional engineer, and the 57 Studios operations representative.

Appendix C: documented incident-response checklist

The documented incident-response checklist is referenced in the event of a documented utility outage. The checklist is posted at the documented operations console and signed off at each documented incident.

1. Confirm the documented utility outage on the documented utility provider's outage map and the documented in-rack power-monitoring system.
2. Confirm the documented ATS transfer to the generator source on the documented ATS monitoring panel.
3. Confirm the documented generator status (running, rated voltage and frequency, documented engine parameters within normal range).
4. Confirm the documented UPS status (battery state, runtime remaining, charging from generator feed).
5. Confirm the documented rack status (servers running, network reachable, documented application-layer health checks passing).
6. Document the documented outage start time, the documented ATS transfer time, and the documented UPS battery state at the time of transfer.
7. Notify the documented operations team of the documented outage and the documented generator-running status.
8. Call the documented fuel-resupply contact and place the documented standby refuel order for delivery within the documented 48-hour window.
9. Monitor the documented generator status across the documented outage duration; document any documented deviations from normal operating parameters.
10. Confirm the documented utility restoration on the documented utility provider's outage map and the documented in-rack power-monitoring system.
11. Confirm the documented ATS retransfer to the utility source on the documented ATS monitoring panel.
12. Confirm the documented generator cool-down and shutdown sequence.
13. Document the documented outage duration, the documented total generator runtime, and the documented fuel consumption.
14. File the documented incident report with the documented operations team and the documented maintenance contractor.
15. Schedule the documented post-incident inspection with the documented maintenance contractor.

Appendix D: documented decision tree for generator sizing

The reference 57 Studios decision tree for generator sizing is documented below. The tree is referenced during the project kickoff and signed off at the documented engineering review.

The decision tree documents the load-bearing decisions in the documented sequence in which the studio's documented engineering practice resolves them. The documented sequence ensures that the documented downstream decisions are documented against the documented upstream constraints.

Appendix E: documented seasonal load profile

The documented seasonal load profile of the reference 57 Studios rack is documented in the table below. The profile drives the documented annual exercise schedule and the documented annual maintenance cadence.

Month	Documented peak rack load (kW)	Documented average rack load (kW)	Documented climate driver
January	198	172	Documented winter heating draw on rack-room HVAC
February	201	174	Documented winter heating draw on rack-room HVAC
March	192	168	Documented shoulder-season HVAC equilibrium
April	188	165	Documented shoulder-season HVAC equilibrium
May	204	178	Documented onset of summer cooling draw
June	214	188	Documented summer cooling draw
July	220	194	Documented summer cooling-draw peak
August	218	192	Documented summer cooling-draw peak
September	209	184	Documented shoulder-season transition
October	196	172	Documented shoulder-season HVAC equilibrium
November	194	170	Documented onset of winter heating draw
December	200	174	Documented winter heating draw on rack-room HVAC

The documented peak month is documented at July (220 kW). The documented engineering review documents the generator sizing against the documented July peak plus the documented combined derating, producing the documented sizing headroom of 21 percent over the documented derated usable output.

Did you know?

The documented seasonal load profile is dominated by the documented HVAC draw on the rack room, not by the documented server load. The documented server load is approximately constant across the year; the documented HVAC draw varies by approximately 25 percent between the documented coolest months and the documented warmest months in the documented reference geography.

Appendix F: documented fuel-resupply contract reference

The documented fuel-resupply contract documents the documented vendor, the documented call-out terms, and the documented response window. The reference 57 Studios contract documents the following parameters.

Parameter	Documented reference value
Documented vendor	Local LP fuel-services provider with documented 24-hour dispatch
Documented call-out number	Documented in the operations console binder; signed off quarterly
Documented response window	24 hours from documented call placement to documented delivery
Documented delivery volume	2,400 to 2,500 gallons (matching documented LP reserve)
Documented after-hours surcharge	Documented at contract signing; reviewed annually
Documented standby retainer	Documented annual retainer for documented priority dispatch
Documented backup vendor	Documented secondary LP fuel-services provider for documented failover

The documented contract is reviewed annually as part of the documented annual operations cycle. The documented annual review documents the documented contract terms against the documented industry baseline and updates the documented contract as necessary.

Appendix G: documented retired and superseded references

The documented retired and superseded references are documented for the documented community's awareness. The studio retains the documented archived configurations for the documented historical context.

Documented retired reference	Documented superseded by	Documented retirement date
Single-fuel diesel 250 kW (initial 2018 configuration)	Dual-fuel NG/LP 300 kW (current reference)	2022-03
Open-transition ATS without bypass-isolation	Bypass-isolation open-transition ATS	2022-06
1,500-gallon LP tank	3,000-gallon LP tank (extended documented runtime)	2022-09
Annual-only maintenance contract	Monthly-quarterly-annual contract	2020-04
Sound-attenuation Level 1 enclosure	Sound-attenuation Level 2 enclosure with supplementary attenuation	2022-11

The documented retired configurations are documented in the studio's published archive. The documented archive is referenced when the documented community asks documented historical questions about the documented evolution of the documented reference configuration.

Visual summary: layered backup-power architecture

                          UTILITY LAYER
                          =============
                          Primary source
                          Documented in [Internet Connectivity Requirements]
                                |
                                v
                          +-----+-----+
                          |   ATS     |
                          | (open-tx) |
                          | (bypass)  |
                          +-----+-----+
                                |
                                +-----------------+
                                |                 |
                                v                 v
                          GENERATOR LAYER     UPS LAYER
                          ===============     =========
                          300 kW dual-fuel    Documented 15-minute
                          NG primary / LP     bridging window
                          secondary           Documented in
                          Documented 72-hour  [Power and UPS Configuration]
                          autonomous runtime
                                |                 |
                                +-----------------+
                                          |
                                          v
                                  RACK LOAD LAYER
                                  ================
                                  Documented 220 kW peak
                                  Documented in
                                  [Recommended Server Hardware]

The documented layered architecture documents the documented role of each documented layer. The documented utility layer is the documented primary source under normal operation. The documented generator layer is the documented backup source during documented utility outages. The documented UPS layer is the documented bridging layer across the documented transfer windows and the documented short outages. The documented rack-load layer is the documented load that the documented stack of layers is documented to protect.

Appendix H: documented generator-room environmental controls

The documented generator-room environmental controls document the documented conditions inside the documented generator enclosure or the documented dedicated generator room. The documented controls are documented at the documented manufacturer's documented installation specification.

Documented ventilation

The documented ventilation system documents the documented air-exchange rate at the documented full-load condition. The reference 300 kW unit documents a documented combustion-air requirement of approximately 1,200 cubic feet per minute (CFM) and a documented cooling-air requirement of approximately 14,000 CFM at full load. The documented ventilation openings are documented at the documented manufacturer's documented sizing.

Documented heating

The documented enclosure heating documents the documented engine-block heater (typically 3 to 6 kW depending on the engine size), the documented battery-warmer pad, and the documented enclosure heater. The documented heaters document the documented start reliability in cold ambient by documented maintaining the documented engine, the documented batteries, and the documented enclosure at the documented manufacturer's documented minimum operating temperature.

Documented cooling

The documented engine-cooling system documents the documented radiator, the documented coolant pump, and the documented thermostat. The documented radiator is documented at the documented full-load heat-rejection rate and the documented worst-case ambient temperature. The reference 300 kW unit documents a documented full-load heat-rejection rate of approximately 280,000 BTU/hr at the documented worst-case 110°F ambient.

Documented monitoring

The documented monitoring system documents the documented engine-controller, the documented ATS-controller, the documented fuel-level monitor, the documented battery-state monitor, the documented enclosure-temperature monitor, and the documented remote-monitoring interface. The documented monitoring is documented at the documented operations console and the documented remote operations dashboard.

Documented monitored parameter	Documented sensor location	Documented alarm threshold
Engine oil pressure	Documented engine block	Below documented manufacturer minimum
Engine coolant temperature	Documented engine block	Above documented manufacturer maximum
Engine speed	Documented flywheel sensor	Outside documented rated range
Alternator output voltage	Documented alternator terminals	Outside documented rated range
Alternator output frequency	Documented alternator terminals	Outside documented rated range
Fuel level (LP tank)	Documented LP tank gauge	Below documented documented refuel threshold
Battery voltage	Documented starting battery terminals	Below documented charge threshold
Enclosure temperature	Documented enclosure interior	Above documented enclosure maximum
ATS position	Documented ATS feedback contact	Documented mismatch with documented command
Documented ATS transfer count	Documented ATS controller counter	Documented for documented service-interval tracking

The documented monitoring system documents the documented alarm-notification path to the documented operations team. The documented notification path documents the documented email, the documented SMS, and the documented in-app notification channels. The documented notification path documents the documented escalation path to the documented on-call engineer.

Appendix I: documented commissioning agent qualifications

The documented commissioning agent is documented as the documented manufacturer-certified field engineer. The documented commissioning agent's documented qualifications include the documented manufacturer's documented factory certification, the documented load-bank testing certification, the documented anti-islanding testing certification (where applicable), and the documented professional engineer's documented credential (where the documented site jurisdiction requires it).

The documented commissioning agent is documented as the documented signatory on the documented site-acceptance test, the documented load-bank test record, the documented anti-islanding test record (where applicable), the documented sound-level measurement record, and the documented project-closeout documentation. The documented commissioning agent's documented signature documents the documented installation's documented conformance with the documented manufacturer's documented specification and the documented project's documented engineering documentation.

The documented commissioning agent's documented engagement is documented in the documented project's documented commissioning contract. The documented contract documents the documented agent's documented scope of work, the documented agent's documented schedule, the documented agent's documented deliverables, and the documented agent's documented fees. The documented contract is signed at the documented project kickoff and referenced at the documented site-acceptance test.

Appendix J: documented end-of-life planning

The documented service life of the reference unit is documented at 25 years at the documented maintenance cadence. The documented end-of-life planning documents the documented decommissioning sequence, the documented salvage value, the documented replacement procurement window, and the documented documented transition plan.

The documented decommissioning sequence documents the documented removal of the documented fuel reserve, the documented disconnection of the documented utility-side and load-side electrical connections, the documented removal of the documented unit from the documented pad, the documented restoration of the documented pad to the documented project closeout condition, and the documented documented disposal of the documented unit's documented engine, the documented alternator, the documented enclosure, and the documented controls.

The documented salvage value is documented at the documented industry baseline for the documented unit's documented age, the documented hours of operation, the documented maintenance history, and the documented documented condition at the documented decommissioning. The documented salvage value is documented in the documented project's documented end-of-life accounting and applied against the documented capital cost of the documented replacement unit.

The documented replacement procurement window is documented at 18 to 24 months from the documented procurement decision to the documented site-acceptance test of the documented replacement unit. The documented window documents the documented manufacturer's documented production lead time, the documented permitting window, the documented installation window, and the documented commissioning window.

Closing notes

The documented backup-generator layer is one of the documented load-bearing layers of the 57 Studios self-hosted server estate. The documented 72-hour autonomous runtime, the documented dual-fuel architecture, the documented open-transition ATS with documented UPS absorption, and the documented monthly-quarterly-annual maintenance cadence together document the documented professional baseline that the studio publishes as the documented reference configuration for the documented community.

The documented community is documented as the documented audience for the documented reference configuration. The documented community is documented to use the documented reference configuration as the documented baseline for the documented community's documented own self-hosted server estates. The documented community is documented to adapt the documented reference configuration to the documented community's documented own site conditions, the documented community's documented own utility service, the documented community's documented own fuel availability, and the documented community's documented own permitting jurisdictions.

The documented reference configuration is documented to be reviewed annually as part of the documented studio's documented annual operations cycle. The documented annual review is documented against the documented industry baseline, the documented community feedback, the documented studio's documented operational experience, and the documented regulatory environment. The documented annual review is documented in the documented studio's documented published archive and is documented as the documented basis for the documented next year's documented reference configuration.

The documented reference configuration documents the documented studio's documented commitment to the documented community's documented professional baseline. The documented reference configuration documents the documented studio's documented investment in the documented community's documented continued reliability. The documented reference configuration documents the documented studio's documented dedication to the documented community's documented continued success in self-hosting the documented community's documented own Unturned server estates.