Community Forums

Las Vegas Rambler · 06-07-2010, 09:30 PM

A Class A in the spot next to me had a situation where all metal in the RV was electrically "hot". He was hooked to a 50 amp breaker and the breaker box had 90 volts on it. Everything metal he touched shocked him.

Using a stick and rubber gloves he unplugged the power. He then turned all the breakers off inside the RV. He then replugged in the 50 amp cable.

Turning on the breakers one at a time revealed that the hot water heater was the culprit.....

I learned something, so thought I'd pass it along to you......

hoppers4 · 06-07-2010, 09:53 PM

Good info. Thanks for the heads up!

Keith Orr · 06-07-2010, 10:53 PM

It also indicates that there is a bad ground on the system. If the metal in the RV was properly grounded he would have tripped a breaker when the water heater shorted to the metal on the body/chassis.

itdave · 06-08-2010, 06:49 AM

It sound like there is an open ground somewhere

ShapeShifter · 06-08-2010, 07:31 AM

Quote:

Originally Posted by itdave

It sound like there is an open ground somewhere

Agreed. And it sounds like that open ground was where the supply lines attach to the campground pedestal, or in the wires supplying it. If the open were in the socket, shore cord, or in the rig, then the pedestal cabinet wouldn't have also been hot.

Glad things worked out, this could've been a dangerous situation. While the immediate problem was the water heater, the ground in the pedestal should've prevented it from becoming so dangerous. The campground should get that pedestal tested and repaired.

wa8yxm · 06-08-2010, 07:52 AM

I will second the bad ground comment. This is fairly common

With a proper safety ground the short in the water heater would have caused the "Click of darkness" (Tripped breaker)

RV Mech Tech · 06-08-2010, 08:08 AM

LVR - just one more reason to test the outlet you are plugging your RV into before you do so - the small testers at HD and Lowe's and elswhere can be connected to a 15 to 30 amp wishbone/adapter for 30 amp and a 30 to 50 amp wb/adapter if required - testing takes very little time and is cheap insurance to prevent your RV from being damaged - over the years we have repaired several RV's with damaged electrical systems because of this , mostly appliance damaged but a couple had burned wiring as well - not alot of fun when you have to open walls in an RV to replace the wiring - it costs a lot of money to upgrade a campground to the electrical standards today and that's why a lot of them have defective systems - also the cg owners may allow a non-qualified non-licensed person to do the repairs to the electrical system- testing the power supply at your campground spot or wherever you plug into and having a surge protector with added functions that can tell you if something is wrong is a good way to protect your RV.

itdave · 06-08-2010, 10:40 AM

I really think these types of problems show why ever Motor Home should have some type of surge protector which also checks voltage and correct wiring.

RVRon · 06-08-2010, 01:33 PM

We went through 3 transfer switches and 1 -50 amp campground pedestal (melted and smoking) with ur '05 Ambassador before we found a short in the Magnadyne Chaeger/Invertor that was putting 117VAC on the neutral circuit in the coach. I heartily agree; check you outlet voltage with a meter and a polarity tester. As they say "An ounce of prevention....."

Las Vegas Rambler · 06-10-2010, 06:39 AM

Good inputs - thank you. Hearing other information is of great value.

The comments on the surge protector and verifying the parks AC confuses me a bit. Still learning I guess. If it was the parks AC or ground, why wouldn't the TV, refigerator, etc also cause the electrification of the RV?
It only happened when the hot water breaker was turned on.

Guess I just need a better understanding for future use. Thanks.

RV Mech Tech · 06-10-2010, 07:18 AM

LVR - that's because the HW heater is where there is a short to ground - if the shore power (campground ) power is o.k., and all the other appliances are o.k. and the electrical circuit in the water heater is the only defect then shutting off the power as the owner did will eliminate the trouble spot and that is isolating the problem circuit - this kind of problem can be anywhere- in the power supply to the RV, in the entrance wiring and panel in the RV, or it can be in an appliance or anything else powered by the electrical system - it's the same principal in a low voltage (12 volt system) as well only the battery is the power source - if you have a defect such as a power wire touching bare metal then the electricity can no longer go along its intended path and then the safety device -the circuit breaker or fuse will shutoff/burnout and shut down the power supply to the conductor(s) if it doesn't then the wiring heats up, the insulation melts and sets fire to any combustionable material nearby - that breaker for the water heater in his RV should have tripped and shut off after he turned it back on - if you want to learn more about RV electrical systems check out www.rvbookstore.com - they have several books on electrical systems and also the 'RV Repair and Maintenance Manual' by RJ Livingston.

itdave · 06-10-2010, 07:26 AM

You are right that the short was in the Water Heater, but what people are saying is if there had been a good ground touching metal in the coach should not have given you a shock. My comment on a surge protector was related to the fact that many of them have built in testing of the wiring of a campground pedestal. The testing checks that the ground is good by checking that there is no voltage between the Neutral and Ground, that there is 240 volts between the two hot legs and that there is 120 volts between the each hot leg and the neutral. Some also check that the voltage is between 104 and 132 at 60 Hz (cycles per second).

TandW · 06-10-2010, 08:14 AM

This to me sounds like the element in the tank burned "open". The current then had a path thru the water to the tank shell. The water is a high resistance path so therefore not enough current could flow to trip the water heater breaker. It is also the reason the poster was able to keep using himself as a ground tester. We can assume in this case that the pedestal had a poor ground.

RV Mech Tech · 06-11-2010, 07:18 AM

In addition to what Dave and others have said, for RV owners a surge protector with all the necessary indicators and built in protection is the minimum everyone should have in their RV-others who know e.systems and those that want to test the connection that they plug into can purchase the testers etc. and check the connections themselves before plugging in their RV's -but as we all know a lot of owners do not and some do not think it's important enough to have that protection - most owners do and they listen, read about, and then purchase whatever is required to protect themselves and their RV - my concern is with the power supply wherever it is that people connect to - in the last two years alone I have seen seven campgrounds with faulty systems - the local electrical authority was notified of the defects in each area and the campgrounds (4 of them) had their systems repaired (at great expense) but three did not and one of them is being sued because their defective system damaged a class C RV that we repaired in our shop - fortunately no one was injured (or worse) in any of those cases - in two of the cases it was found that unqualified people had been repairing the system including repairs to the posts and connectors at the RV sites and incorrect connections were the result- when it comes to electricity or propane no one can afford to take any chances- if someone has a problem with a campground connection then the owners should be notified and if they do not do anything about it then the local electrical authority should be notified before someone gets injured.