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Q: Normal voltage drop?

Yahoo Message Number: 11182
We recently dragged out and tried to use an electric skillet for the first time in our coach. As soon as I turned it on the voltage inside the coach dropped about 14 volts - from 118 VAC to about 104 VAC.
When we tried to use the electric toaster at the same time the voltage dropped to about 90 VAC. When I tried the same loads hooked directly to the power pedistal, the voltage drop way much lower - maybe only
2-4 volts. The coach is hooked to 50 amp shore power.

I'm wondering if others experience such large voltage drops when relatively large electrical loads are applied inside the coach.
One side-effect of the heavy load was that the TV cable connector in the wet bay overheated (actually melted the plastic insert in the connector) and I had to replace the connector.

My theory is that the electrical system was seeking more ground capacity and decided to use the path through the TV cable.

If the voltage drop is abnormal, any ideas how I might troubleshoot the problem?
--

Tom Harsch 2002 Allure 36'

Re: Q: Normal voltage drop?

Reply #1 –
Yahoo Message Number: 11186
Tom,

There should never, never be any significant amount of current through the Cable TV connector, -- period. The Ground conductor in the shore power cable is a protective safety ground and should never conduct any significant current. It's sole purpose is to trip a circuit breaker in case of a wiring fault or other short circuit condition, thus limiting the possibility of a fire or electrical shock. Any significant current on ANY Ground conductor indicates a serious and potentially dangerous electrical problem.

I would have a competent electrician check this out ASAP as you could have a serious problem on your hands.
As for the electric skillet and toaster, if they are connected to the same circuit, you are seriously overloading it. A standard 120 Volt outlet is only rated for 15 Amps total load, the coach circuits are rated for 20 Amps, and either of these appliances will use most if not all of that.

Good Luck,
Dave

2000 Allure 36'
#30444

Tom & Maxine Harsch wrote:

Re: Q: Normal voltage drop?

Reply #2 –
Yahoo Message Number: 11187
Hi Tom,

I have had this problem occur in houses also.
Generally, it's the return (white) wires not secure in the ac circuit breaker panel, certainly all the wiring is suspect in your case at the terminations on both ends. For the kitchen slide, there are splices in the slide area where flex and romex wiring are joined. CCI did not do a good job on documentation in this area. All terminations should be verified. Sometime ago I reported on a somewhat similiar problem: the strapping in the dc circuit breaker/fuse panels were never secured in our coach.
Fred Kovol

Inverter failure (was: Q: Normal voltage drop?)

Reply #3 –
Yahoo Message Number: 12114
Thought I'd update the group on the apparent cause of having current run through (and partially melt) the cable TV connection in our coach.
The bottom line is that the Trace(/Xantrex) (RV-2012) inverter was not properly switching the neutral line when shore power was applied.
Replacing the inverter control board solved the problem.

CC tech support, Xantrex tech support, several electricians and RV repair people were unable to explain or solve the problem. It wasn't until we parked overnight at a location where the shore power connection included GFCI protection that the source of the problem became apparent. Whenever I plugged into a GFCI protected outlet the breaker would trip if (and only if) the inverter input breaker was turned on - even if the inverter output line were turned off (i.e., only the charger section was active).

The Buffalo, MN Xantrex service center (Terry Korthof) was able to reproduce the GFCI trip condition and after consulting with Xantrex tech support, decided an internal neutral switching relay wasn't operating properly (probably due to a failed capacitor). Apparently this particular failure mode was previously unknown to Xantrex tech support.

Terry Korthof certainly earned my respect for diagnosing the problem.
I'd highly recommend contacting him for any inverter problems if you happen to need help while travelling in the upper midwest - I added an entry to the CC service/repair database with contact information (see the "Buffalo, MN" item).
--

Tom Harsch 2002 Allure #30791

Quote from: Dave Hills\[br\
]

Re: Inverter failure (was: Q: Normal voltage drop?)

Reply #4 –
Yahoo Message Number: 12120
On our old coach - a hunk of junk Fleetwood product - while replacing the U-Joints in Joplin Mo with only 12k miles on it and it was 100+ outside our generator quit - no plug-ins at the repair shop - couldn't get the generator fixed - drove to Kansas City, Topeka and Denver with stops between attempting to get generator fixed - north of Denver at a Fleetwood place they would not even look at our problem since we hadn't purchased the coach there - after repeated calls to Fleetwood (and some strong language) we were finally directed to Casper Wyoming - not planned but went there - problem diagnosed as an inverter problem - they would sell me a new one for $1500 - called Xantrex in Arlington WA - they told me it was probably a "slow-blow fuse" - problem there was the Casper shop didn't have one or know how to put it in - Xantrex shipped the fuse to my daughter in Boise - three repair shops in Boise couldn't take the inverter apart - called Xantrex back and finally just decided to go to Arlington WA - 20 minutes and no charge the "slow-blow fuse was replaced and the inverter checked out - thought our problem was solved but NO - at Redmond and FMCA a few years back Fleetwood thought it was my battery cables - those fixed or replaced and still had problems - went to Onan - they couldn't fix the problem there but could in Boise - so back to Boise and generator fixed - we finally traded the coach after the bay where the power comes in caught fire and U-Joints replaced again at 24k miles - Thank God for Country Coach -

Clint Frederick (Inspire #51038 - and glad of it)