converting a portable generator to a floating neutral

[Cleveland Apprentice]

I have a manual transfer switched that doesn't switch the neutrals between utility and gen power (non-SDS). I have a generator that does not have a "floating neutral." I understand that I must have a floating neutral to work with this type of transfer switch or I would have parallel current traveling on the EGC back to the gen. If I converted this to a floating neutral, wouldn't this make the generator a dangerous set up if I decided to use this as a stand alone generator for other purposes? I am curious of what options there are. Thank you.

 

[zbang]

I think you named them- bonded neutral when you're using it as a SDS/standalone and floating neutral when it's connected to the transfer switch. Some people modify the generator with a bonding switch. Honda does have some service bulletins that describe how to remove the jumper, other manufacturers might too.

 

[kwired]

After you do remove the bonding jumper, it will not be any different than any generator that does have a floating neutral. All non current carrying equipment still needs to be connected together via equipment grounding conductors. The resulting system if not connected to a premises wiring system is an ungrounded system, and is code compliant and some may actually claim is overall safer than a grounded system. (there are advantages as well as disadvantages to an ungrounded system) One advantage is if you have a ground fault on any conductor you don't really have much of a hazardous condition, you simply have a system that is now grounded at the point of the fault. A second ground fault on another system conductor will cause high current flow and cause overcurrent protective devices to open the circuit.

If it is connected to a premises wiring system the neutral to ground bond is done at the service main bonding jumper and equipment grounding conductor of the generator supply conductors/cable is what bonds the generator frame to the premises wiring and it becomes part of a grounded system.

 

[hillbilly1]

I wish I could find my owners manual on my 5 kw Coleman generator, but it shows using a dummy 15 amp male cord cap with the neutral and ground jumpered together when being used as a SDS.

 

[kwired]

I wish I could find my owners manual on my 5 kw Coleman generator, but it shows using a dummy 15 amp male cord cap with the neutral and ground jumpered together when being used as a SDS.

Dummy is the correct term. Guess what happens to the bonding jumper when somebody wants to plug in another cord and forgets or doesn't realize what this device is for?

 

[hillbilly1]

Dummy is the correct term. Guess what happens to the bonding jumper when somebody wants to plug in another cord and forgets or doesn't realize what this device is for?

Yeah, I was really surprised the manufacture had that in print! Of course this is a 25+ year old generator, but there were lawsuits back then too!