Name: Generac Home Standby-20 Generator Set
Brand: Generac

Fuel	Natural Gas or L.P. Vapor
Frequency	60.0 Hz
Standby power	20 kW
Standby kVA	39
Prime power	15 kW
Controller	Solid-state
Oil capacity	3.8 L
Alternator	MMC 4G15 (2-pole, Class Class F insulation)
Voltage options	120/240 V
Phase	1
Rated current	83.3 A
Power factor	1.0
Circuit breaker	100 A
Battery group	1
Battery voltage	12 V
Battery quantity	1
Coolant capacity	7.5 L

for the Generac MMC 4G15

Item	Spec	Capacity	Part #	Interval
Air filter	N.G./L.P.		—	100 hr
Fuel filter	N.G./L.P.		—	100 hr
Oil filter	N.G./L.P.		—	100 hr
Battery	N.G./L.P.		—	100 hr
Belt	N.G./L.P.		—	100 hr
Coolant	Cooling system with coolant capacity of 2 US gallons, radiator capacity of 1.75 US gallons, and coolant flow rate of 10.6 US gallons per minute		—
Oil	Gear type oil pump, full flow, cartridge oil filter	3.8 L	—
Spark plug	N.G./L.P.		—	1000 hr

What size generator is the Generac Home Standby-20?

The Generac Home Standby-20 is rated 20 kW standby (39.0 kVA).

What engine is in the Generac Home Standby-20?

The Generac Home Standby-20 is powered by the Generac MMC 4G15 engine.

What fuel does the Generac Home Standby-20 use?

The Generac Home Standby-20 runs on Natural Gas or L.P. Vapor.

How much oil does the Generac Home Standby-20 take?

The Generac MMC 4G15 engine in the Generac Home Standby-20 has an oil capacity of 3.8 liters.

What alternator does the Generac Home Standby-20 use?

The Generac Home Standby-20 uses a MMC 4G15 alternator. It has 2 poles. Insulation class Class F.

Rating	Load	L/h	gal/h
Prime	100%	204.0	85.0
Standby	100%	265.0	110.0

Reference — 0166590SBY (Generac)Parts manual — E21590SBY (Generac)