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Kohler 20rz - neutral connection

JTN

Registered
I have a 20rz that came to me after 30 years, but only 600 hours of run time. Very well maintained. I'm getting ready to wire it into my house setup into a new 200amp Kohler RES transfer switch.

For it's entire life the neutral from the transfer and the neutral from the stator lands on what looks like a ground block. The 4th ground wire from transfer lands on this block also.

So, if I want to unbond ground and neutral since neutral is NOT switched at the transfer, can I simply connect the neutral to panel to the stator neutrals with a splice? It looks like they paralleled neutrals off of L2 and L3 (4 wires), and L1 and L4 are the hots with two wires each. Single phase. This is very confusing to me because kohler still bonds neutral to ground on their brand new generators sold today.

I have most of the manuals for this machine but no install manual or wiring diagram.

It runs fine off a 15 gal propane tank at idle. 20200228_115942.jpg
 

Zephyr7

Registered
I would leave the ground/neutral bond in the genset.

If you want to break the ground/neutral bond and have it bonded only at the ATS (you MUST MUST MUST have a ground/neutral bond in at least one of those two places!), the best way to do it is to use a glastic insulator. Bolt one end of the insulator to the ground bar that’s on the generator where everything is connected now, then land all the neutral connections on the bolt on the other end of the insulator. Use split lockwashers on the bolt heads and grade 5 hardware. You need 1/4-20 studs in the glastic insulator.

Bill
 
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JTN

Registered
I would leave the ground/neutral bond in the genset.

If you want to break the ground/neutral bond and have it bonded only at the ATS (you MUST MUST MUST have a ground/neutral bond in at least one of those two places!), the best way to do it is to use a glastic insulator. Bolt one end of the insulator to the ground bar that’s on the generator where everything is connected now, then land all the neutral connections on the bolt on the other end of the insulator. Use split lockwashers on the bolt heads and grade 5 hardware. You need 1/4-20 studs in the glastic insulator.

Bill
Bill,
I do have a ground/neutral bond immediately after the meter in a separate disconnect. The transfer switch is not my service disconnect, and follows after the main service disconnect. So it's meter>disconnect(ground/neutral bond)>transfer switch>main panel>several sub panels that all carry 4 wires.

My concern with them bonded again, with a 2 pole transfer switch that does not switch neutral, is that current could be sent back over ground while using 110v devices, which could lead to the panel cases having current on them. Low risk, yes, but it is something I have been thinking about.
 

Zephyr7

Registered
That issue with hot chassis only happens if the neutral opens, which is unusual. Admittedly, the reason I like to have a bond in the genset is in case the ground opens in the genset which is also unusual.

If you need to break that bond at the genset, use a glastic insulator. If you can’t find one let me know and I can get you in touch with one of my vendors who will sell you one (usually they like to sell larger lots).

Bill
 
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