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Service rated transfer switch

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I have a customer that purchased 20KW generator and 200 Amp service rated transfer switch. The only problem is that we would be wiring up transfer switch not as service rated but in basement feeding generator panel. He didn't realize he has a 300 Amp split service with two 150 amp main panels. Regardless my question is would it be fine to use this switch in this application? I would feed it with 100 amps from one of panels and put dedicated generator panel next to it. Obviously all bonding and grounding would stay as is in main discos but will the 200 amp main in transfer switch be a problem? I'm guessing not because it will just be a redundant disconnect and and wire will be protected by 100 amp feed in panel
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Gamit said:
I have a customer that purchased 20KW generator and 200 Amp service rated transfer switch. The only problem is that we would be wiring up transfer switch not as service rated but in basement feeding generator panel. He didn't realize he has a 300 Amp split service with two 150 amp main panels. Regardless my question is would it be fine to use this switch in this application? I would feed it with 100 amps from one of panels and put dedicated generator panel next to it. Obviously all bonding and grounding would stay as is in main discos but will the 200 amp main in transfer switch be a problem? I'm guessing not because it will just be a redundant disconnect and and wire will be protected by 100 amp feed in panel
Transfer switch is rated higher than the feeder, no problem.
 

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Big John said:
Service rated transfer switches need to be able to completely isolate the load. A normal TS isn't capable of doing that as it's always connected to either Normal or Emergency. That's the primary difference I'm aware of. In your case, you're fine because you have upstream isolation.
The generator panel could be main lug assuming the generator has ocp.
 
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