Overview#
The Generac SD175 is a 175-kilowatt industrial diesel standby generator powered by a Generac-branded 6.7-liter turbocharged and aftercooled inline-six engine. Rated at 175 kW standby and 158 kW prime (219/197 kVA), the SD175 is a technical step above the SD130 despite sharing the same displacement: its 4-valve cylinder head, electronic fuel injection, and a larger 19.6-quart crankcase deliver higher output. Exhaust temperature is 1040°F (560°C) -- the highest in the mid-size SD Series -- and heat rejection to coolant is 497,718 BTU/hr. The generator is EPA Certified for Stationary Emergency applications.
The SD175 uses Generac's 520 mm alternator frame with Permanent Magnet excitation, Class H insulation, and THD less than 5%. The Digital H control panel provides NFPA 110 Level I and II programmable operation, Modbus communications, and a 7-day programmable exerciser. The 1500W block heater and closed coolant recovery system are standard.
At 175 kW, this unit serves the upper tier of commercial standby: large office campuses, hospitals and healthcare facilities with significant critical loads, larger data center UPS bypass power, industrial manufacturing with motor-heavy loads, and large retail or mixed-use developments.
Technical Specifications#
| Parameter | Value |
|---|---|
| Standby Rating | 175 kW / 219 kVA |
| Prime Rating | 158 kW / 197 kVA |
| Engine Make | Generac |
| Displacement | 6.7 L (406.9 in³) |
| Cylinders | 6, In-Line |
| Bore x Stroke | 4.09 x 5.2 in (104 x 128 mm) |
| Compression Ratio | 16.5:1 |
| Aspiration | Turbocharged/Aftercooled |
| Fuel Injection | Electronic |
| Engine Speed | 1,800 RPM |
| Alternator Model | Generac 520 mm |
| Insulation Class | H |
| Fuel Type | Ultra Low Sulfur Diesel #2 |
| Fuel Consumption (100%) | 13.5 gph |
| Fuel Consumption (75%) | 10.5 gph |
| Fuel Consumption (50%) | 7.3 gph |
| Fuel Consumption (25%) | 3.9 gph |
| Exhaust Flow | 1,326 cfm at rated output |
| Exhaust Temperature | 1,040°F (560°C) |
| Heat Rejection to Coolant | 497,718 BTU/hr |
| Combustion Air | 470 cfm |
| Ventilation Air | 7,946 cfm |
| Open Set (no tank) L x W x H | 117 x 50 x 57 in |
| Open Set Weight (no tank) | 3,980 lbs |
| Max Radiator Air Temperature | 122°F (50°C) |
| Max Ambient Temperature (Before Derate) | 104°F (40°C) |
Our Service Experience#
The SD175's electronic fuel injection system is more complex to service than the mechanical Stanadyne injection found in the SD130. Electronic injectors require clean, dry ULSD fuel -- maintain biocide treatment and annual fuel polishing for any tank that sits for extended periods. Injector removal and testing requires dedicated diagnostic equipment.
The 1040°F exhaust temperature is demanding on exhaust system components. Exhaust flex connectors must be rated for this temperature range and replaced on a shorter interval than in lower-output machines. Verify clearances from combustibles at installation and at every annual service visit.
At 13.5 gph full load, a 510-gallon sub-base tank provides approximately 37 hours of runtime. For 72-hour NFPA 110 Class 72 applications, the 946-gallon or 1325-gallon tank options are required.
Frequently Asked Questions#
Why does the SD175 use a Generac engine when the SD130 uses an Iveco/FPT engine? The SD130 uses the Iveco/FPT 2-valve version of the 6.7L with mechanical Stanadyne injection. The SD175's spec sheet identifies the engine as Generac-branded, with a 4-valve head and electronic injection. This is a higher-output variant of the same 6.7L block with a different cylinder head and injection technology. The larger crankcase capacity (19.6 vs 17 qt) and higher BMEP (257 vs 213 psi) confirm the more demanding output calibration.
What motor starting capability does the SD175 have? With the standard 520 mm alternator (rated 200 kW) at 480 VAC and a 30% voltage dip, the SD175 can start 560 sKVA of motor load. With Upsize 1 (250 kW alternator), the capability reaches 790 sKVA. With Upsize 2 (300 kW alternator), it reaches 908 sKVA at 480 VAC. This is sufficient for large HVAC chiller starting in facilities with multiple rooftop units.
Is the SD175 appropriate for hospital emergency power systems? Yes. The SD175 with NFPA 110 Level I programmable control meets the requirements for Type 10, Class X, Level 1 emergency power supply systems in healthcare applications subject to NFPA 110 and NFPA 99. Confirm with the project's electrical engineer that the specific installation meets the authority having jurisdiction's requirements, particularly for life-safety loads.
