Community Forums

Spike25 · 10-18-2017, 12:47 PM

Can anyone tell me why when I plug my 30 amp class c into a 15 amp reducer and plug it in to my garage outlet it blows the breaker to my garage outlet? This never did this before. Just got the motorhome back from the shop and they replaced the whole breaker box. Nothing in the motorhome is on when I plug it in. Thanks.

powercat_ras · 10-18-2017, 12:56 PM

Make sure your Electric Hot Water switch is off when you plug in your RV to a 15 amp outlet. The Converter-Charger in your RV will draw about 4-5 amps when first powered up, the hot water heating element will draw 13-14 amps the combination of the two will open a 15 amp breaker.

l1v3fr33ord1 · 10-18-2017, 01:09 PM

Spike25-

Why did you have the breaker box replaced?

Is the outlet in your garage a GFCI outlet?

Did this happen before you had the breaker box replaced?

Rocky Larson · 10-18-2017, 01:12 PM

I agree with Powercat, plus add draw from refrig.
Then again, why was the breaker box in need of replacement?

Might start there and work backwards. Good Luck

PS: Anything in the garage or house on the same 15amp circuit? It all adds up....

Spike25 · 10-18-2017, 01:33 PM

Quote:

Originally Posted by powercat_ras

Make sure your Electric Hot Water switch is off when you plug in your RV to a 15 amp outlet. The Converter-Charger in your RV will draw about 4-5 amps when first powered up, the hot water heating element will draw 13-14 amps the combination of the two will open a 15 amp breaker.

I had the breaker box replaced because all the negative wires burnt up. Jayco said it was a bad transfer switch. But not sure. Someone said it was a power surge. I used to be able to plug it in with no problem but now it keeps popping. Water heater is off and so is the fridge.

BrianGlenn · 10-18-2017, 01:39 PM

Shut off all breakers including main in the coach AC distribution panel and plug it in - if it still blows then the shop may have miswired the main feed, or your shore power cord/plug is damaged.

Start by flipping on the main, and then individual breakers one-by-one until the problem repeats itself. When it trips, that's the problem circuit....

As mentioned, if your garage outlet is GFCI protected and there is a current leak in your coach then it will trip.

My thoughts,
Brian

Spike25 · 10-18-2017, 01:42 PM

Quote:

Originally Posted by l1v3fr33ord1

Spike25-

Why did you have the breaker box replaced?

Is the outlet in your garage a GFCI outlet?

Did this happen before you had the breaker box replaced?

The breaker box was replaced because all the negative wires inside burnt up. They said it was the transfer switch but after opening it they said it was a power surge. This never happened before it was replaced. The outlet in the garage is GFCI

Mr_D · 10-18-2017, 01:43 PM

Have you tried a different circuit in the house? I suspect the new panel is wired wrong but you need to try another plug in on a different circuit to be sure.

BrianGlenn · 10-18-2017, 01:48 PM

Quote:

Originally Posted by Spike25

The outlet in the garage is GFCI

For reasons that only electricians can describe

two GFCI's in series seems to give trouble and one/other will prevent electrical/current flow.

Possibly your GFCI in the coach is tripped? Now I'm talking beyond my knowledge level.....pay grade....

Brian

Spike25 · 10-18-2017, 02:42 PM

Quote:

Originally Posted by BrianGlenn

Shut off all breakers including main in the coach AC distribution panel and plug it in - if it still blows then the shop may have miswired the main feed, or your shore power cord/plug is damaged.

Start by flipping on the main, and then individual breakers one-by-one until the problem repeats itself. When it trips, that's the problem circuit....

As mentioned, if your garage outlet is GFCI protected and there is a current leak in your coach then it will trip.

My thoughts,
Brian

Thanks Brian. I called the repair shop and they told me to turn on the generator and put on the appliances. If nothing trips then the wording is fine. I will try what you said.

Spike25 · 10-18-2017, 04:20 PM

Quote:

Originally Posted by Spike25

Thanks Brian. I called the repair shop and they told me to turn on the generator and put on the appliances. If nothing trips then the wording is fine. I will try what you said.

Sorry wiring.

BrianGlenn · 10-18-2017, 05:35 PM

Quote:

Originally Posted by Spike25

Thanks Brian. I called the repair shop and they told me to turn on the generator and put on the appliances. If nothing trips then the wording is fine. I will try what you said.

By turning on the generator the transfer switch will energize and provide 120V AC power to your coach AC distribution panel from the onboard generator. Putting maximum load - Air conditioner, electric water heater (make sure it is full of water), hair dryer running plugged into outlet, microwave a cup of water, etc, etc will load up the generator. IF nothing trips then the wiring in the coach is OK. There is a breaker on the generator and it SHOULD trip if it is overloaded.

It does not confirm the main electrical cord up to the transfer switch is good, or that the shore power circuit is good.

Disconnect shore power before you power up generator (not usually needed) and it will confirm the transfer switch is working properly. If it is not, you'll have no AC power into the coach.

Good luck,
Brian

powercat_ras · 10-18-2017, 06:56 PM

Did you see burnt up wires yourself or is someone telling you this? Technically there is no way a bad transfer switch would damage your original breaker box. That said, it is not unusual for a loose wire connection in a breaker box to cause a problem, but this is normally resolved by cutting any damaged wire back to good and reconnecting with proper torque, verifying proper torque on all connections in the box while at it. If the loose connection is on a breaker, then sometimes this causes the breaker to fail too, but each breaker is removable and replacable.

Hopefully the replacement breaker box was correctly installed, per code and RVIA requirements for RVs, with all the neutrals and grounds kept separate as it was in your original breaker box. If not kept separate then your coach will never work on a GFCI like it did originally.

twinboat · 10-18-2017, 07:51 PM

A GFCI outlet is NOT a breaker. It doesn't trip due to amperage overload. It trips due to a fault to ground.

Many times the water heater element is run dry and shorts to the element covering, which is connected to the threads and ground. Even with the water heater breaker off, the neutral wire is shorted to the ground wire, a ground fault. Disconnect the white wire from the element as a test.

Other problems are ice makers and fridges. They can be unplugged to test.

If you added a surge guard, they also can trip GFCIs.

Of course, there is the possibility that they wired something wrong, but telling you to run it on generator, is not proof that all is well. The generator isn't grounded to the house electrical system, where the ground is actually driven into the ground.