generator ocpd and feeder

[electrofelon]

So I am far from home, kind of on vacation, helping a friend install a generator. I decided i would not bring my codebook because I thought things would be straightforward, but sure enough murphy came along and the generator is set up a bit differently than the ones I usually do. The location is a residence, 100A automatic 2- pole transfers swtich (thus not a sds). Generator is 17 kw kohler. Every generator I have done has a breaker on the generator, so I simply size the wire to that breaker. However the manual of this unit implies that it just has a terminak block (I dont have the unit yet but need to get the groundwork done due to limited time). If this is the case:

1. Do I need to install a dsco at the generator? From memory I think there is a "if within sight" qualifier but i dont recall if that is for a disco at the generator or where the feeder connects to the premises.

2. How is the generator feeder sized/protected. Do I need an ocpd or since the generator is current limited do I size the wire to the generator max current plus a safety factor like with a pv system?

Thanks, I much appreciate any input.

 

[73cj5]

Is there an OCPD in the transfer switch??

 

[electrofelon]

Sorry for the delay,

There is not OCPD in the transfer switch. The transfer switch is not service rated and is located in between a 100 amp service disconnect breaker and a MLO panel. I would say that the generator feeder needs overcurrent protection of some type, but I am not sure since it is a current limited source. I am willing to bet that the generator has a breaker in it, even though the manual says some versions do not.

 

[chris kennedy]

Every generator I have done has a breaker on the generator, so I simply size the wire to that breaker. However the manual of this unit implies that it just has a terminak block (I dont have the unit yet but need to get the groundwork done due to limited time)

If this gen-set doesn't come with an OCP device, I'll send you a dollar.

 

[360Youth]

If this gen-set doesn't come with an OCP device, I'll send you a dollar.

I have seen them and wired them, but they are usually much older units. If genset does not come ith onboard OCP then I would say that a disconnecting means needs to be installed before it enters the building. I did one a few months ago w/o OCP and set disconnect on outside of customer built shed enclosure. Wire size would be same with or without OCP, rated kw plus 15% per 445.13.