Generator: Bonding Neutral to Ground

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Old 11-21-19, 04:12 AM
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Generator: Bonding Neutral to Ground

My old generator had a bonded neutral. The new one has a floating neutral. Currently the neutral bar is isolated from the ground in the generator sub panel. My question is should I bond them there or at the Inlet? "First point of disconnect" seems to be at the inlet where a 30 amp, 240v twist lock cord is plugged in. Also I called my generator manufacturer and the tech guy insisted on me cutting off the ground plug going from the generator to the inlet. What's the reasoning for that? It seems shady to me to not ground the generator. At that point I would need to drive a separate ground rod and ground the generator to that before I would dare operate it. Thanks for your help.
 
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Old 11-21-19, 04:20 AM
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The generator should float as usually the bond is made at the electrical panel when hooking a generator to the home through a transfer switch.

What panel/transfer switch do you have?

If your transfer switch is the type that switches out the neutral then yes you would want to have a bonded generator.

Currently the neutral bar is isolated from the ground in the generator sub panel.
Pictures would help. What do you mean isolated?
 
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Old 11-21-19, 04:23 AM
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It depends on how your inlet and transfer switch is wired.
If your inlet is wired to the load center (breaker panel) and your transfer switch does not switch neutral, then you want to just plug your generator as is.
Neutral and ground is bonded at the main panel. There is no need and you shouldn't bond at the generator end.

Why would anyone tell you to cut off ground when the generator has floating neutral? That makes no sense.
 
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Old 11-22-19, 03:51 AM
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Thank you both for your advice. It makes sense what you are saying. I have a power max 30 amp transfer switch that transfers 120v. It transfers the neutral and one of the hot lines from the generator into my "main" (inverter's) panel when the generator is turned on. The thing is that the inverter is a Xantrex that feeds the "main" inverter's panel through a gfci outlet so the neutral and ground are separate at that panel also because it would naturally trip the gfci outlet on the inverter. So the neutral is being dumped to the ground at the inverter. When the house outlets are being powered by inverter, a receptacle tester reads Properly Wired and Grounded. When the Generator is powering the outlets, the ground light on the receptacle tester blinks. In other words, the neutral is not being dumped into the ground. I noticed something was up when I had a breaker turned off and my volt tester went off when it was next to a neutral wire.
 
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Old 11-22-19, 04:35 AM
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Electrons are not trying to get to ground. They want to return to the source they came from.
 
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Old 11-22-19, 04:37 AM
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Maybe I should just bond the neutral to the ground at the generator plug. Didnt have any issues with my old generator that had a bonded neutral.
 
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Old 11-22-19, 05:29 AM
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Here's a Diagram

https://photos.app.goo.gl/hcMQifmMrM8dzAt56
 
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Old 11-22-19, 06:53 AM
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This is beginning to look how a boat is wired. I take it that there is a large battery bank feeding the inverter? And, if AC is available, the inverter is in a charge mode?

Basically, you want to get to the point where whatever is feeding the service attaches the N to G. But, only one. So, in your case, that should be either the service bonding at the service panel OR the invertor, Or any generator; but, only one. This will force you to understand if the N is switched at the transfer switch, and if the inverter has auto N to G connect. Also, there may be a requirement to NOT connect either battery + or - to G. Most invertors do not isolate between batts and line.
 
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Old 11-22-19, 07:12 AM
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The 4kw Inverter has a built in charger and transfer switch. It will transfer generator power to its loads and charge batteries at the same time. Battery bank is 500AH connected to both inverters and charged from solar panels/charge controller. I updated the diagram. See below.

https://photos.app.goo.gl/Cr57JhZmjx8RmjXA6
 

Last edited by Luke Underwood; 11-22-19 at 08:22 AM.
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Old 11-22-19, 09:57 AM
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So, I now see power sources included the genset, and two inverters. Is there no POCO connection? ie; this is all off-grid?
 
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Old 11-22-19, 10:17 AM
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Correct, no connection to grid. So maybe the gen panel is the "Main" Panel? It supply 7000w and can transfer to both inverters.
 
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