How to Convert Briggs & Stratton 5500 Wheelhouse to floating neutral

[Sir Topham Hatt]

The trassfer switch I have (Connecticut Electric 10-7501) appears not to switch
neutral. My B&S generator, bonds the neutral to the ground, as do most portable
generators. For reasons that I don't quite understand, this is not a safe combo
since neutral is grounded in 2 places, the service panel and the generator, so
with some research it appears I need to convert the bonded neutral to a floating
neutral. I would like to convert the B&S generator to floating neutral, has
anybody done this? Googling, I found a reference to how to do this for the
Genrac Wheelhouse model (which B&S purchased I believe) and all you had to do is
remove a jumper from one of the AC 120V outlets. So that I can still use the
generator (safely)ndalone generator, I can reintroduce the neutral bonded to
ground, by simply making a 120V plug with the neutral jumped to the ground and
plug it into one of the 120V outlets.

So basically I want to be able to use the generator as backup to my house and a
safe portable.

 

[Sir Topham Hatt]

If you are going to use it only for power failure and unplug it the rest
of the time then you don't need to make any change in the generator. If
it will be left connected to the transfer switch nearly all of the time
then you do have to have a means to open the bond when you leave it
connected to the house when using the utilities power.

Tom,
To start off, thanks for responding.

Just to clarify this statement, just having the generator plugged into the
transfer switch and not running, while under utility power is not recd.?
If this is the case, I have no problem with this since I only plan to connect to
the transfer switch during a power outtage

So lets say I hook the generator up during a power failure and switch all
crticial circuits to the generator at the switch. So far so good. Now 2 hours
latter, the utility power comes back on. If I go out to the yard to shut the
gen off, am I in any danger of shock if I touch the genrator frame?

The reason that having a bond on the load side of the service
disconnecting means is a bad thing is that in the event of a failure of
continuity of the neutral conductor the neutral current would be flowing
on the exterior conductive surfaces of appliances, metal face plates,
metal framed tools, raceway, etc.. A second failure in the continuity
of the equipment grounding (bonding) conductor would raise the surface
of all conductive parts of the system to the applied circuit voltage.

I don't quite understand this. This is what I understand from you post

- bond of the load side of the service (that is my genrator's neutral bonded to
ground)

I start getting confused with the "disconnecting means is a bad things ..."
sentence.

..

 

[Sir Topham Hatt]

Thomas,
Thxs again for answering my questions.
I understand the part to shut off the generator and disconnect it before
returning to utility power!

Let me explain my transfer switch. It is indeed a circuit by circuit design.

The wire whip coming out of the transfer switch for each circuit (10 circuits)
have a black and red pair. You diconnect the black (hot) from the circuit
breaker for the circuit you want to control with the black coming from the
switch and tie those together. You then connect the corresponding red to the
breaker. You do this for all of the 10 circuits. The whip of the switch also
has a white and green while. You connect the white to the neutral buss of the
panel and the green to the grounding buss of the panel. The 2 busses are bonded
in me service panel (GE Loadcenter). A 30 AMP power cord connects the gen, to
the switch.
Its all documented here:
(http://www.connecticut-electric.com/online/EmerGenManual.pdf)



So with that said and what I am interpetting the only dangeours condition is if
there is a neutral fault on one of the circuit under the generator power while
there is also utility power (to the other circuits) or is the fault condition
more complicated than this?

So if there is a fault, what gets energized in the path?

thxs
Joe

 

[Sir Topham Hatt]

Thxs. I called Connecticut Electric and basically has told the same by the
Engineer who designed the switch. He told me there is lots confusion and around
this portion of the NEC code and the next version will help clarify this issue.