Kohler 150ERESC generator wire pull

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electrofelon

electrofelon

Senior Member
Location
Cherry Valley NY, Seattle, WA
Occupation
Electrician
Is anyone familiar with this or similar generator? It's a typical Kohler 150kw natural gas light commercial generator. My question for anyone familiar with these, can I reasonably do a wire pull of two sets of 500 MCM into the wiring/breaker compartment of this unit or should we have the wires in place and lower the generator over top of the already pulled conductors? Conduits are in the slab at the proper location per the schematic I was given. I ask because I have done some smaller 40 to 50 KW Kohler generators where it would not have been real fun to do a wire pull into them (these didn't have conduit entries in the slab though so it didn't matter). The unit has not arrived so I am unable to look at it. This is a bit of a pain as I'm having to coordinate my travel, forklift rental, generator delivery, and a ditch being dug and it would help to know the required order of operations. Thanks.
 
I just looked at cheat sheet from another place, U seem high on wire size - is voltage drop involved?
looked at manufactured web site it is truly is NG - 600 amps, but
reading 310.16 using THHN 3Ph 4 wires size 350 gives 350 amps - wire 300 gives 320 amps , 2 - 3" parallels for 700 AMPS.
or 2 - 3" for 640 amps respectfully.

nothing else considered, is 3" PVC an answer your looking for? 3/0 EGC for first THHN.
I realize 310.16 3ccc...
 
cadpoint said:
I just looked at cheat sheet from another place, U seem high on wire size - is voltage drop involved?
looked at manufactured web site it is truly is NG - 600 amps, but
reading 310.16 using THHN 3Ph 4 wires size 350 gives 350 amps - wire 300 gives 320 amps , 2 - 3" parallels for 700 AMPS.
or 2 - 3" for 640 amps respectfully.

nothing else considered, is 3" PVC an answer your looking for? 3/0 EGC for first THHN.
I realize 310.16 3ccc...
Click to expand...
Nameplate current is 520 amps, X 1.15=598 amps so 2 sets of 500 AL. Yes 3" PVC.

BTW why were you using the 90° column for your ampacity numbers?
 
ActionDave said:
I'm not familiar with kohler generators that size, but given my experience with cat and onan I would not be surprised if the wiring compartment was the same size as a post office box.
Click to expand...
Yeah I pretty much assume things that were not designed by electricians are going to be absolutely retarded to wire. The smaller Kohler generators I did, wiring had to come in the side, had to drill through the c channel base skid, and a real pia coming into the cabinet with a 90° seal tight connector you could barely make fit or get your hand into.
 
L
electrofelon said:
Nameplate current is 520 amps, X 1.15=598 amps so 2 sets of 500 AL. Yes 3" PVC.

BTW why were you using the 90° column for your ampacity numbers?
Click to expand...
I believe he is using CU instead of AL for the calculation, you did not specify which in your original post, I believe that’s where the confusion is. If I remember correctly, with that big of an alternator, the breaker enclosure is fairly high off the frame. Seems like it is around 2’.
 
Just landed a 100kw NG Kohler the other day. Junction box is open bottom under the breaker. Probably 24" to bottom of the breaker. No issues fitting 2 sets of 500al in.Screenshot_20220617-220949_Photos.jpg
 
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