Estimating generators is relatively simple. A careful review of the specs and knowing where the generator is located will prove most helpful. The location sometimes can be tricky.
Be sure to review the acceptable manufacturers listed in the specification. Quotations from different manufacturers can vary greatly. Some manufacturer’s engines have different RPM’s. Be sure to check the specifications carefully.
Generator Estimate Checklist
- Generator labor for site conditions and location?
- Crane for offloading and setting?
- Rigging if generator is going in basement?
- Concrete pad?
- Bollards or fencing?
- Diesel fuel for load testing?
- Fuel for a full tank at completion?
- Natural gas piping?
- Exhaust work?
- Exhaust insulation?
- Commissioning labor?
- Factory representative required for start-up?
- Maintenance warranty?
Be sure to read the generator spec carefully. Be sure to get a clear scope of your responsibilities if the generator and ATS is owner furnished. Even though others furnish the generator, you may be responsible for the maintenance for the first year.
How many gallons do I need for testing?
Here is a general rule of thumb for estimating diesel fuel for testing:
100% Load Test = KW X .08 = gallons per hour
75% Load Test = KW X .06 = gallons per hour
50% Load Test = KW x .04 = gallons per hour
Example: a 100% load test for a 350KW generator for 8 hours
350KW x .08 x 8 = 224 gallons
I have a detailed listing of standard Caterpillar diesel generator units up to 2,000 KW. This listing has fuel consumption, weights, and dimensions. It also lists the weights and dimensions with weatherproof enclosures. A basic concrete pad size is noted with the size shown in square feet.
If you will send me a request by email, I will forward you this chart.
Remember, estimating is expensive, poor estimating is costly, and quality estimating is profitable!