50-amp connection

[jdkinzenbaw]

Hi everyone,

I have a 2012 Road Warrior 30C fifth-wheel toyhauler. We were staying at a nice campground last night, and I was at a full 50-amp hookup. Late evening, the voltage in the camper appeared to fluctuate. The lights would dim significantly, the radio would shut off. The A/C never quit, although I'm not sure why. After a few minutes, the lights would get to full bright again. This happened many times over the course of 2 hours or more.

So, I'm wondering: Was the drop in voltage caused by a power overload on the campground's 50-amp service, or something inside my camper? In the process, I plugged a voltage meter into one of the indoor outlets, and the outlet was putting out a steady 130 volts.

I tried starting up the generator to see if that corrected it, but it did not. Now, hours later, I'm questioning whether I would have needed to also unplug the 50-amp service before the camper would begin using the generator for power. This morning, things seemed to work fine, all the appliances worked good, lights were nice and bright, etc.

So is this an issue with my camper, or am I right about the draw on the campground's 50-amp service, since I didn't unplug from that before starting the generator? This is the first electrical issue I've had with my camper, and I haven't made any modifications to any of its systems, and I store it indoors in a heated shed in winter, so it doesn't seem likely that I'd be having this issue this early on.

Thanks in advance,
Jonathan

 

[brianharrison]

Were they 120V lights and 120V stereo system - or were they the 12V lights and radio - ie will work when no shore power is connected? IF the latter I am wondering about your converter providing proper charge rate. Check the battery terminals while connected to shore power - should be greater than 13.2 V - probably 13.6 or 14.4V.

The power from the generator should switch over the transfer switch to take feed from the generator, shutting out shore power.

Brian

 

[Birchwood]

Where are you,sometimes if its really hot and most RVs have their AC s blasting the park electrical will not handle the load.

 

[jdkinzenbaw]

Thanks, Brian. That's a good point. The lights and radio do work when the shore power is not connected. They'll run off battery power, so you may be onto something. That would also explain why the A/C never quit and why the power outlets were showing steady voltage. It is obviously 120V.

As far as the power from the generator - wouldn't you still need to be disconnected from shore power before it would supply power? I would think you'd risk feeding power back onto the shore grid and wouldn't some kind of safety code ban that so you don't end up frying an electrician when he's out working on the lines?

Birchwood - the temps last night were actually in the low-70's. We were actually just running the A/C to chase some of the high humidity out - the air has been really damp here recently; more than we were comfortable trying to fall asleep in.

 

[danemayer]

Jonathan,

Most of the lights in our RVs are 12V, and the radio can be either 12V or 110V. So if the lights were flickering and the radio went off, the most likely cause is the voltage dropping below 12V coming off the combination of power converter and battery. If everything is working right, the power converter or the battery will supply adequate voltage to run lights and radio and more. So one possibility is that you may have a problem with the power converter. That would also lead to low voltage on the battery.

As Brian said, when you start the generator, after a few seconds the transfer switch operates relays that switch from shore power to generator power. It's not necessary to unplug from the pedestal. Since the problem is probably with the 12V system, switching to the generator probably wouldn't help. Except that it might get you back to normal voltage levels - keep reading.

The 130V reading on the outlets is concerning. That's pretty high. Electrical Management Systems/Surge Protectors will shut down at 132V to protect the coach. A Progressive Dynamics 9200 Power Converter will also shut down at 132V to protect itself.

Putting all that together, I suspect over voltage at the pedestal caused the Power Converter to temporarily shut down. The battery should have carried the load for the lights and radio without your noticing the changeover, but it didn't. That suggests the battery charge is low, or the manual-reset circuit breaker between battery and power converter has tripped and your lights aren't getting any power from the battery.

Our owner-written 12V Block Diagram and Diagnostics Guide may help you track down the problem. Of course, now that everything is working better, it may all check out ok.

Sounds like you'd benefit from an Electrical Management System/Surge Protector. The first page of this document explains some of the the reasons for getting one.

 

[jdkinzenbaw]

Jonathan,

Most of the lights in our RVs are 12V, and the radio can be either 12V or 110V. So if the lights were flickering and the radio went off, the most likely cause is the voltage dropping below 12V coming off the combination of power converter and battery. If everything is working right, the power converter or the battery will supply adequate voltage to run lights and radio and more. So one possibility is that you may have a problem with the power converter. That would also lead to low voltage on the battery.

As Brian said, when you start the generator, after a few seconds the transfer switch operates relays that switch from shore power to generator power. It's not necessary to unplug from the pedestal. Since the problem is probably with the 12V system, switching to the generator probably wouldn't help. Except that it might get you back to normal voltage levels - keep reading.

The 130V reading on the outlets is concerning. That's pretty high. Electrical Management Systems/Surge Protectors will shut down at 132V to protect the coach. A Progressive Dynamics 9200 Power Converter will also shut down at 132V to protect itself.

Putting all that together, I suspect over voltage at the pedestal caused the Power Converter to temporarily shut down. The battery should have carried the load for the lights and radio without your noticing the changeover, but it didn't. That suggests the battery charge is low, or the manual-reset circuit breaker between battery and power converter has tripped and your lights aren't getting any power from the battery.

Our owner-written 12V Block Diagram and Diagnostics Guide may help you track down the problem. Of course, now that everything is working better, it may all check out ok.

Sounds like you'd benefit from an Electrical Management System/Surge Protector. The first page of this document explains some of the the reasons for getting one.

Good information, Dan. I'll try some of these things out. Last night, we didn't have that problem in the camper, and I noticed that the batteries are showing full charge now. If it does it again, I'll check these symptoms you've mentioned. I really appreciate the help! Read that article, too, about the boy being killed by an incorrect electric ground. Scary stuff! Good lessons learned... like most things in life, take the time to do it right the first time, and you'll never have a problem.