Generac · MD Series (Modular Diesel)

Generac MD500

500 kW standby / 450 kW prime · Diesel · Liquid-cooled

500 kW modular diesel standby generator system. Factory-paralleled configuration with Perkins 15.2L inline-6 engine for N+1 redundancy.

Standby power
500 kW / 450 kW prime
Voltage options
277/480V, 346/600V
Frequency / Phase
60 Hz · 3-phase
Engine
Perkins 15.2L · 15.2L
Alternator
Generac K0500124Y23
CommercialManufacturingHealthcareData Centers
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Overview#

The Generac MD500 is a 500 kW modular diesel standby generator system powered by a Perkins 15.2-liter turbocharged and aftercooled inline-six engine. Part of Generac's Modular Power System (MPS) platform, the MD500 is factory-configured with integrated paralleling controls for plug-and-play scalability. Multiple MD500 units can be deployed together for N+1 or N+2 redundancy, supporting multi-megawatt backup power architectures for large data centers, hospital campuses, and critical infrastructure.

At 500 kW per module, the MD500 occupies a popular power node for mission-critical facilities. Two MD500 modules provide 1,000 kW of total capacity with full redundancy, comparable to a single SD1250 but with the operational flexibility of independent units. Individual modules can be serviced or replaced without taking the entire system offline.

Our Service Experience#

The MD500 shares the proven Perkins 15.2L platform with the SD500. At 32 gph full load per module, fuel logistics for multi-unit installations require careful planning. We recommend independent fuel supply verification for each module and staggered exercise schedules. Paralleling controller calibration should be verified at commissioning and annually, with particular attention to load sharing balance across modules under varying load conditions.

Engineering specifications

Physical

Length
154.4 in
Width
71 in
Height
67.3 in
Dry weight
10,435 lb

Fuel system & runtime

Fuel use @ full load
32 GPH
Fuel use @ 75% load
24.2 GPH
Fuel use @ 50% load
17.5 GPH

Thermal & ventilation

Heat to coolant
648,307 BTU/hr
Exhaust flow
3,955 CFM
Exhaust temp
1022 °F
Combustion air
1,483 CFM
Ventilation air
30,582 CFM

Documents & downloads

Spec sheets & manuals

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Estimate runtime for the Generac MD500

Adjust load percent and tank size to estimate runtime. Pre-filled with this model's spec where available.

Estimate runtime on this tank

Estimated runtime

8.1 hours(0.3 days)

Fuel consumption ≈ 24.69 GPH at 75% load. Estimate based on industry-typical 1800 RPM standby curves (≈0.07 GPH/kW at full load). Actual consumption varies by engine, ambient temperature, fuel quality, and tuning.

Service intervals

Manufacturer-recommended intervals for the Generac MD500 under standby duty. Field intervals may differ based on load profile, ambient conditions, and fuel quality.

Oil & filter
Every 500 hours or 12 months
Air filter
Every 1000 hours
Fuel filter
Every 500 hours
Load bank test
Every 12 months

Common failure modes

What we've seen fail on this platform. Use as a service-planning reference, not a diagnostic — actual failure modes depend heavily on duty cycle and maintenance history.

ComponentSymptomTypical hoursSeverity
Fuel quality / degradationHard starting, filter clogging, reduced power output4,380+moderate
Paralleling controller synchronizationFailed sync, load sharing imbalance, hunting20,000+moderate
BatteryFailed to start, slow cranking8,760+minor

Frequently Asked Questions

What is the difference between the MD500 and the SD500?
The MD500 is a modular (factory-paralleled) system designed for scalable, redundant power architectures. It uses the same Perkins 15.2L engine as the SD500 but comes factory-configured with integrated paralleling controls, enabling plug-and-play expansion with additional MD units. The SD500 is a single-unit standalone generator at the same power rating. The modular approach provides N+1 redundancy, easier installation logistics, and the ability to service one unit while another continues operating.
What is the fuel consumption of the MD500?
The MD500 uses the same Perkins 15.2L engine as the SD500. At standby rating, fuel consumption is approximately 32.0 gallons per hour at full load, 24.2 gph at 75% load, and 17.5 gph at 50% load per module.
What voltages are available?
The MD500 is available in three-phase configurations at 277/480V and 346/600V, both at 60 Hz.

Compatible equipment

Transfer switches

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