Overview#
The Generac SD020 is a 20-kilowatt industrial diesel standby generator powered by a Perkins 2.22-liter turbocharged inline-four engine. Rated at 20 kW standby and 18 kW prime, it is the top of the Perkins 2.22L platform within Generac's SD lineup, sharing the same compact footprint as the SD010 and SD015. EPA Certified for Stationary Emergency applications, the SD020 is available in single-phase and three-phase configurations across voltages from 120/240V through 346/600V.
Generac pairs the Perkins engine with their K0025124Y21 alternator (Class H insulation, synchronous brushless excitation) and the Digital H control panel with NFPA 110 Level I and II programmable operation. Standard equipment includes an engine coolant heater, closed coolant recovery system, and factory-filled coolant and oil.
At 20 kW, this unit covers most small commercial emergency loads. The ability to upsize from 10 or 15 kW within the same installation footprint makes the SD020 a popular choice when preliminary load calculations result in slightly higher demand than the SD015 can supply.
Technical Specifications#
| Parameter | Value |
|---|---|
| Standby Rating | 20 kW / 25 kVA |
| Prime Rating | 18 kW / 23 kVA |
| Engine Make | Perkins |
| Displacement | 2.22 L (135 in³) |
| Cylinders | 4, In-Line |
| Aspiration | Turbocharged |
| Compression Ratio | 23.3:1 |
| Engine Speed | 1,800 RPM |
| Alternator Model | K0025124Y21 |
| Insulation Class | H |
| Fuel Type | Ultra Low Sulfur Diesel |
| Fuel Consumption (100%) | 1.68 gph |
| Fuel Consumption (75%) | 1.38 gph |
| Fuel Consumption (50%) | 1.06 gph |
| Fuel Consumption (25%) | 0.80 gph |
| Exhaust Flow | 245 cfm at rated output |
| Exhaust Temperature | 625°F (329.4°C) |
| Heat Rejection to Coolant | 83,610 BTU/hr |
| Combustion Air | 87.9 cfm |
| Open Set (no tank) L x W x H | 76.0 x 37.4 x 44.8 in |
| Open Set Dry Weight | 1,456 -- 1,641 lbs |
| Max Ambient Temperature | 122°F (50°C) |
Our Service Experience#
The SD020 represents the limit of the Perkins 2.22L engine platform in the Generac lineup. Above 20 kW, Generac transitions to the larger 3.4L Generac-branded engine (SD035/SD050). The SD020 is well-supported from a parts perspective given the wide use of this Perkins 400-series engine across many industrial applications.
From a service standpoint the SD020 is practically identical to the SD010 and SD015: same oil capacity, same coolant system, same fuel filter servicing. The distribution injection pump is the component most sensitive to fuel quality -- maintain fresh ULSD and perform annual fuel polishing on tanks that see extended between-test intervals. Battery and coolant heater inspection should be standard at every annual service visit.
Frequently Asked Questions#
Is the SD020 appropriate for single-phase 120/240V applications? Yes. The SD020 delivers 20 kW at 83 amps (1.0 pf) on 120/240 VAC single-phase, making it suitable for small facilities with single-phase service. Most small commercial applications in this power range use single-phase service; the three-phase 120/208 or 277/480V configurations serve facilities with three-phase distribution panels.
What sub-base tank options are available? Sub-base fuel tanks are available with usable capacities of 54, 132, 190, 211, and 300 gallons. All are UL 142 double-wall construction with rupture basin alarms. Runtime at full load ranges from approximately 31 hours (54-gallon tank) to 176 hours (300-gallon tank).
Can the SD020 be installed in a sound-attenuated enclosure? Yes. Level 1 and Level 2 sound-attenuated enclosures are available in both steel and aluminum for all SD-series small diesel units. The Level 1 enclosure measures 112.5 x 38.0 x 49.5 inches (no tank configuration). The Level 2 enclosure adds additional sound absorption material for installations in noise-sensitive locations such as urban commercial districts.
