Questions to ask
In order to provide the right equipment for your customer’s needs, you will need to get some important information. According to Garcia at Doosan, following are some questions to ask before supplying a generator:
- What is the generator being used for?
- How many hours per day will the unit run?
- If long-term, who will perform 250-hr service and do they need fuel delivery? Do you need an additional external fuel tank and who will hook it up?
- What voltage do you require? 208V, 240V or 480V and single- or three-phase?
- If you need 208V and 480V, do you want two generators or one generator and a transformer?
- How many amps do you need?
- If you want a transformer, what size (amps or kVA)?
- What kind of connections do you need? Lugs, stud, cam-lok or something more specific such as a certain NEMA configured pigtail?
- Do you need primary feeder cable? If you need #1, 2/0 or 4/0, how many four- or five-wire sections do you need? (If someone says they need 200’ of feeder, they might actually mean 1,000’ of cable or 200’ x 3 hots, a neutral, and a ground.)
- Do you need a PowerSource for standby generator? If yes, would you like a transfer switch? If so, do you want manual or automatic?
- Do you need distribution? If yes, how many 20-amp 110V duplex circuits do you need?
- How far apart do you desire the outlets to be?
- Do you have a layout?
- Do you need any 220V outlets? If yes, where, how many, what amperage, and what plug configuration?
- Do you need cable ramps? How many total feet?
- Do you need the equipment to be setup and taken down?
- Do you need a standby technician?
The rental perspective
Don Leher, industrial sales manager at Gen-Tech in Glendale, AZ, is in the business of helping customers choose the right generator for the job, and he says it comes down to getting as much information from that customer as possible.
Leher says they run into challenges when someone needs a generator set to start and run a large motor. This may be a pump system, or a building with a large number of small motors that can, and do, all start at the same time.
“In these instances we always try to determine the horsepower of the motors to be started, starting sequences if possible, and the method used to start the motor,” he says. “A motor starting across the line can have a starting kilovolt amps demand that is six to 10 times the normal running amps, or it could be coupled to starting methods that minimize the starting demand. With this information we can normally provide a temporary generator to meet their needs without over sizing, and therefore over pricing, the unit.”
He continues, “The more information we can glean up front, the better match we can suggest for the project in terms of on-site power generation.”
Unfortunately, many times temporary generators are sent to jobsites that are over sized because either the information was not available or no one asked the right questions. “In the rental generator business knowledge is king, just as it is in all business,” Leher says. “Knowing the right questions to ask, and asking them, is the best way to ensure the needs of the project are met.”