I have 2 100hp motors that will be installed on a barge to operate 2 conveyors. It will be run most of the time with shore power but we have the option of running it with generator power also. There will be 4 1000watt lights also installed with this service. I want to install a transfomer to run the motors so not as much load will be placed on the generator when the motors are switched on or off so there will be less surging of the generator engine. I believe I need a 400 amp service. My coworker says no transformer is needed and thinks we only need a 200 amp service. Please let me know what you guys think. Or do you guys have a better idea Thanks.
Proper way to hook up 2 3 phase 100hp motors
- Thread starter ryandumas
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- San Francisco Bay Area, CA, USA
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- Electrical Engineer
Uh, have your co-worker do the math on that. Even if you have a 600V service, that's 200A right there.
If you can keep both motors from starting simultaneously, you would have ~100+ amps steady-state with one motor running and you attempt to start the second load. What does the starting load look like, i.e. an easier centrifugal load or something very hard to start? You are asking to size the "service" but what is the generator capacity? That seems to be to be a larger issue than the service size right now.
dbuckley
Senior Member
- Location
- Canterbury, New Zealand
You may like to consider a soft start or VFD to limit the start up current that the genset will have to supply, or you will need either an oversized generator, or one with poor protection equipment, so that when you online start the second motor and the genny revs drop dramatically, the genny just keeps going through the overload and doesn't under-speed stop.
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