Temporary Generator Breaker

[FaradayFF]

Greetings,
Are the rental portable generators come with adjustable output breakers? For example, if I got 50kVA unit, would it have adjustable settings on the breakers which would allow me to set the trip at 100Amp? This would give flexibility with sizing the cable from the genset to the load.

Thanks,
EE

 

[zbang]

I've never seen one but I don't generally get anything larger than maybe 200-250kva; certainly haven't on something smaller like a 50kva. (Ideas of "small" may vary )

OTOH most rental companies also rent breakers in boxes (and temp attachment leads).

 

[Todd0x1]

Really depends on the breaker. Some rental units have the ABB SCAE breakers with the electronic trip. Other units have oddball cheap Japanese fixed thermal mag breakers.

I have one that has an interesting scheme to trip the breaker at a lower amperage when in 480v mode, there are CTs run through a motor overload relay which then activates the shunt trip on the breaker.

What cable are you using that needs to be breakered at 100A?

 

[hillbilly1]

I think the smaller units like that, do not, at least what I have seen, if they are multi voltage, they may have ct's that monitor for overload, and shunt trip the breaker.

 

[Todd0x1]

Really depends on the breaker. Some rental units have the ABB SCAE breakers with the electronic trip. Other units have oddball cheap Japanese fixed thermal mag breakers.

I have one that has an interesting scheme to trip the breaker at a lower amperage when in 480v mode, there are CTs run through a motor overload relay which then activates the shunt trip on the breaker.

What cable are you using that needs to be breakered at 100A?

Should have read "Really depends on the generator...."

 

[don_resqcapt19]

240.21(B)(5) can give you a lot of flexibility, if the load end OCPD is on the building , or nearest the point of entrance inside the building.