My generator is sending power to the shore power cord

[billk42]

OK lets see if I can explain.  I will start with a statement of what is my issue, then try and explain the situation. 

My generator is sending power to the shore power cord

OK here goes:  Everything is fine, cleaning the RV, putting things away, no problem, nice weather dogs happy, life is good.  Coach is plugged in to shore power at our house (30 Amp system).  Everything is fine all day.  Nothing in coach running except TV.  Shut everything down, all fine.  Will leave the Coach plugged in as I always do when not travelling. 

Now, go outside after dinner,  notice there is no power to coach..hmmmmm.  Check the outlet, it is tripped, hmmm...reset, trips again.  Unplug the shore power , start investgating, decide to start the genny and see whats happening.  OK here goes the best part and my ISSUE.    When the genny starts and the transfer switch kicks in, I plug the shore power in and it blows the breaker....OK get out the meter,  guess what..120 volts on the plug....coming from the coach, the genny is putting 120 volts on my sore power cord??? HELP.  I gotta figure it has something to do with the transfer switch, but I don't know what to do next.

By the way, I have a Todd Transfer switch, we have 30 amp service .

 

[PancakeBill]

To state the obvious, the transfer switch is not working correctly.  I assume that it used to work fine, this rules out wired incorrectly.  Be very careful, don't run the gen.  Have it checked out.

 

[John From Detroit]

There are basically two types of auto-transfer switches

one type has a single set of double throw relays.  When the generator starts, and the timer expires the relays pull in and transfer the loads to the generator....

The other type has two sets of single pole normally open relays

When shore power is detected That set of relays pulls in and, one hopes, locks out the generator

When generator power is detected,, again one hopes, it pulls in the generator set and locks out the other

Now... If a relay gets "Welded" in the closed position (Can happen due to connecting/disconnecting/transfering under load) and does not drop out like it should


What you have can happen.

 

[Gary RV_Wizard]

You probably need to replace the transfer switch. I don't know anybody who repairs them. Obviously it could be done, but labor and parts to repair likely equals the cost of a new one in most cases, so shops don't bother. If you have the skills, you might be able to do it yourself.

 

[billk42]

I was afraid of that, I do have the skills, unfortunately money is a bit tight, any guess how much something like this costs?
ANd Thanks by the way

 

[Lou Schneider]

If you don't want to repair the transfer switch, get rid of it. 

Hard-wire the coach breaker panel to the shore power cord and put a 30 amp outlet on the output of the generator.  Mount the 30 amp outlet inside the compartment where you store your shore power cord for travel, and simply plug the rig into the generator outlet whenever you disconnect from shore power.

The only downside is having to go outside and manually transfer the cord to the generator if you lose shore power in the middle of a stay.

 

[Ned]

If it isn't obvious from Lou's post, all the needed connections are there where the transfer switch is located.  It would be an easy solution, even if it's only until you get a new transfer switch.

 

[John From Detroit]

Transfer switches consist of relays and control board(s).  The main part is the relay and if you can find them, or a slightly "Better" one (IE: if yours are rated at 50 amp and you find one that can carry 60 amp but is otherwise the same size, shape and coil, GO FOR IT) or if the relay you have is rated 150 volt and you find one rated 400 that can carry the current has the same coil draw and fits in the same mounting)  by all means

If you have to have it done professionally.. Cheaper to replace cause at 100+/hr for labor the control borad or boards are worth perhaps 25 bucks,  and the case, the same, that makes replacement less costly than repair.

 

[Just Lou]

You stated that your system was 30 amp.

The IOTA-30amp transfer switch ranges from $55 to $125 on the net.  It comes complete with a wiring diagram and description of typical installation and theory of operation.  I used this switch when installing my inverter three years ago and it's still working fine.

If you understand your current wiring you won't have any difficulty replacing the switch.  Go for it....

 

[John From Detroit]

Thnaks OnA... At 125 for a full replacement v/s 100+/hr 1 hr minimum plus parts to repair it.. NO CONTEST

 

[billk42]

Thanks for all the help, I am going to look at the one suggested, found it on-line already and it isnt expensive.  And Im very comfortable doing it myself.. Thanks to all

 

[Ron]

Thanks for all the help, I am going to look at the one suggested, found it alone already and it isnt expensive.  And Im very comfortable doing it myself.. Thanks to all

Gkad you found what you need.  Please let us know how it works out.