Transfer Switch Trouble

[Paul]

I have a automatic transfer switch with RV power protection that works with shore power.
It does not work with the portable generator and shore cord from the bus. The generator is a Honda EX4500S with a floating neutral. I would like to use this generator to power our bus till we get a diesel unit mounted permanently on our bus.
Can anyone help me figure out how to make this work, without letting the smoke out?
Thanks to anyone that can help.
Paul

[bevans6]

Which transfer switch do you have?  120 or 240 volt ac?

Brian

[Sean]

Paul,

You need to bond ground and neutral IN the generator.

For one, it is a safety issue -- without this bond, none of your safety grounds can do its job.  But secondly, this is probably the reason your transfer switch will not connect.

You don't say what make and model of ATS you have.  But you did mention "power protection."  Most such systems are looking to see the same voltage hot-neutral and hot-ground, and your un-bonded generator will fail this test.  The protection circuitry sees this as a fault (as well it should) and refuses to connect.

Consult your Honda documentation to see how to properly bond ground and neutral inside the generator.  Do NOT implement this bond in the coach wiring -- that will create a very different hazard when you connect to shore power.

-Sean
http://ourodyssey.blogspot.com

[Paul]

Thanks Brian & Sean For the reply

The transfer switch is a TRC Surge Guard model 40250   240 volt 50 amp.
             www.surgeguard.com

My Honda Manual no help.

Honda Power Equipment Division telephone help NO HELP.
Ask them about bonding the ground in the generator. They would not reply on doing the bounding.

[Paul]

Try this

http://www.trci.net/products/surge-guard

[Sean]

...My Honda Manual no help.

Honda Power Equipment Division telephone help NO HELP.
Ask them about bonding the ground in the generator. They would not reply on doing the bounding.

OK.  I could not find any documentation for this model on-line, either.  You have a couple of choices:

First, since the genny is no longer under warranty (I assume), there is probably no harm in simply opening up the panel cover and installing a bonding jumper between the ground and neutral of whichever receptacle you are using.  That would be the "best" solution in terms of the bus, although it may create problems if the generator gets used for house-backup purposes.

The other option would be to do it in the pigtail.  Since your coach likely has a 14-50P plug on the shore cord (standard 50-amp, 120/240-volt RV plug), but the generator has an L14-30R receptacle (twist-to-lock type, 30-amp, 120/240-volt), I assume you have either purchased or built an adapter which converts from one to the other, IOTW it has an L14-30P plug on one end, and a 14-50R receptacle on the other.

Unless this is a pre-made adapter with molded ends, you should be able to open up either the plug or receptacle end of the pigtail.  Note: do this only on the pigtail, not on the shore cord.  Once you have it open, loosen the ground and neutral terminals and add a short length of #8 wire, green or white, between the neutral and ground terminals, then re-tighten the terminals.  Make sure you torque them properly -- you are basically now mashing two stranded wires in each terminal.

All of this still applies if you have a 30-amp coach, in which case your shore cord will have a 5-30TT-P ("travel trailer") plug, whereas the genny has an L5-30R (30-amp, 120-volt, twist-to-lock) receptacle, and, again, you will have an adapter to switch between them.

If your adapter is the molded-end type, you will have to cut one end or the other off and replace it with a screw-on plug or receptacle.  Plugs are easier to come by, but locking type are pricey, whereas the non-locking receptacles are probably cheaper when you can find them.

Give me a shout if you need further.

-Sean
http://ourodyssey.blogspot.com

[Sean]

http://www.trci.net/products/surge-guard

I'm familiar with those products.  Which model do you have?

Most of these will "protect" you from an open ground, which is how your genny will read to the control circuitry.  If you have the one with the display, that's what you should be seeing -- "open ground."

-Sean
http://ourodyssey.blogspot.com

[Paul]

Working on coach 4 years 2 months 6 days some equipment out dated before first trip.

The generator is a 120/240 volt, with 30 amp 120 volt twist lock receptacle, 120 volt duplex receptacle and a 120/240 volt four wire twist lock receptacle.

I use the 120 volt 30 amp twist lock receptacle on the generator with.

120 volt 30 amp twist lock male to 120 volt 30 amp RV female receptacle adapter with.

120 volt 30 amp RV male to 50 RV female receptacle adapter to.

50 amp RV Shore Cord

Do you think the 30 amp 120 volt male twist lock would be the safest place for the bounding?  That way I would not be altering the generator. We plan on getting a generator soon we hope.

This will be are first time out with the Bus in four years. It is still a steel tent BUT INSULATED WITH PLYWOOD WALLS!!!!!!!

Paul

[Marcus]

You all just reminded me why I didn't put a transfer switch in . I guess I just made  it idiot proof. I have to manually unplug the shore cord , so I just plug it into the genny receptacle. Kiss method. Marc

[Sean]

Do you think the 30 amp 120 volt male twist lock would be the safest place for the bounding?  That way I would not be altering the generator.

Yes, just make certain that (1) the pigtail thus altered does NOT remain connected to the shore cord when the generator is not in use and (2) the pigtail is properly labeled as to use and function (e.g. "Coach connection only -- ground and neutral bonded").

-Sean
http://ourodyssey.blogspot.com

[Sean]

You all just reminded me why I didn't put a transfer switch in . I guess I just made  it idiot proof. I have to manually unplug the shore cord , so I just plug it into the genny receptacle. Kiss method. Marc

And if you were using the described generator with this method, you would have a potentially deadly situation.

Note that the problem we are talking about has little to do with the transfer switch -- it has to do with an improperly bonded generator, and a "protector" device (that is available with or without a transfer switch).  The protector device did its job, and alerted Paul to a dangerous generator.  With your setup, you would have no such warning.

So, KISS, maybe, but better, not so much.

-Sean
http://ourodyssey.blogspot.com