voltage reading on frame

[Buckeye-travelers]

We have a 2014 Sundance 3300 CK 5[SUP]th[/SUP] wheel thathas had strange electrical issues since we purchased it new. Some items wereaddressed by the dealer but some issues remain and now that we are out of warrantyI am working on my own to try to resolve the issues.
Thefirst issue is that the house battery seems to go dead very quickly (4-6 hourswith nothing left on and only an occasional light turned on to get to therestroom in the night). I am postingthis in the 120-volt section because I believe I have isolated the issue to bewithin those systems but don’t know enough about electrical systems to go muchfurther.
Pursuing the belief that the battery should last longer, Ihad to assume that there was a short causing the battery to drain. To test that theory, I attached an electricaltester to the frame and stuck the black probe into the ground and received a constantlychanging reading of .05 to .20 volts. (Voltage coming off of the battery issolid at 13v and house current is solid at 118v). Feeling that my theory had some merit Iguessed that there must be a staple in a wire somewhere so I set out to findout which circuit the damage might be on. One at a time I turned off breakers and pulled fuses but none of themcaused the small voltage reading to change or even drop. I then removed the leads from the battery andagain, no change. Finally, I cut theshore power and the reading went to “0”. I am assuming that this means there is an issue between the inverter andthe circuit panel but have not found any shorts etc.

The second issue is that two electrical components acterratically. The multi-function media system (DVD- Stereo etc.) works at timesand at others it won’t. The only thing that resolves the issue is to unplug andre-supply the shore power. The other issue is with the High Pointe microwave.It comes on by itself when shore power is connected and after shutting it off,works normally. (MW has been removed for safety reasons).

I havebeen planning to add a second battery to help with the power when dry campingbut want to be sure I don’t have a dangerous issue I am ignoring. These may also be separate issues but if thereis a chance they are related, I wanted to post all in the same area.

Any inputwould be greatly appreciated.

 

[danemayer]

Hi Buckeye-travelers,

I attached an electricaltester to the frame and stuck the black probe into the ground and received a constantlychanging reading of .05 to .20 volts. ........ Finally, I cut theshore power and the reading went to “0”. I am assuming that this means there is an issue between the inverter andthe circuit panel but have not found any shorts etc.

You have what's called a "Hot Skin". Since it goes away when shore power is unplugged, it's clearly a 120V AC problem. Although at the moment the voltage is very low, "Hot Skin" is a very dangerous condition. Normally the 120V AC power comes in on a 'hot' wire, goes through the appliance that's being powered, and returns on the 'neutral' wire. The ground wire in the circuit is to protect you in case there's voltage leakage through an appliance defect. The power is supposed to flow to the ground, and back to the pedestal and not through the skin, and potentially through you, to earth ground.

If the leakage gets worse, someone could be injured or killed by touching the trailer skin or steps while standing on wet ground.

To isolate the problem, try turning off one circuit breaker at a time until the leaking voltage goes to zero. That will identify the circuit where the leakage is occurring.

Also, check your power cords to make sure the connections are tight, and there's no discoloration that would indicate a bad connection. With shore power disconnected, you might also inspect the back side of the circuit breaker panel for loose or damaged wires.

Your surround sound and microwave problems could be a result of an earlier electrical problem. If you have a 50 amp trailer, problem with the neutral connection can cause voltage to go up toward 240V on one power leg. That can fry electronics or just damage the electronics causing weird behavior. It's similar to what can happen from a lightning strike.

Before going too far into battery drain, check the water level and if that's ok, have the battery tested.

 

[Garypowell]

Don't know a whole lot about this but with my first rig in 1996 ran into a hot skin condition. Got a tingle when I was checking my lug nuts before departure. Searched for an hour and finally had to leave. Never saw it again.

I have since learned that the shore power can have a "bad" neutral and this can cause voltage on the frame.

 

[MP_CS]

I worked as an electrician and electronics repair technician for motorola for some years and have seen loose nuetral and ground connections cause various oddball symptoms, stray voltage is one of them. You should check your shore power connections at the inverter and at the shore power recepticle on the outside of RV. To check the idle draw on you're battery turn your DVM to DCA and unhook the pos side of battery and check and see what the current draw is, with with everything off there should be very little draw.

 

[Buckeye-travelers]

I have turned off breakers and pulled fuses one by one an none made a difference which leads me to believe the issue is isolated between the shore power and the inverter (or possibly the panel, whichever comes first). I was counting out the 110v line through the camper because the reading was so low but it looks like some think those connections are worth checking. I will do more prodding as recommended and get back with you all. Thank you for your input!

Hi Buckeye-travelers,



You have what's called a "Hot Skin". Since it goes away when shore power is unplugged, it's clearly a 120V AC problem. Although at the moment the voltage is very low, "Hot Skin" is a very dangerous condition. Normally the 120V AC power comes in on a 'hot' wire, goes through the appliance that's being powered, and returns on the 'neutral' wire. The ground wire in the circuit is to protect you in case there's voltage leakage through an appliance defect. The power is supposed to flow to the ground, and back to the pedestal and not through the skin, and potentially through you, to earth ground.

If the leakage gets worse, someone could be injured or killed by touching the trailer skin or steps while standing on wet ground.

To isolate the problem, try turning off one circuit breaker at a time until the leaking voltage goes to zero. That will identify the circuit where the leakage is occurring.


Also, check your power cords to make sure the connections are tight, and there's no discoloration that would indicate a bad connection. With shore power disconnected, you might also inspect the back side of the circuit breaker panel for loose or damaged wires.

Your surround sound and microwave problems could be a result of an earlier electrical problem. If you have a 50 amp trailer, problem with the neutral connection can cause voltage to go up toward 240V on one power leg. That can fry electronics or just damage the electronics causing weird behavior. It's similar to what can happen from a lightning strike.

Before going too far into battery drain, check the water level and if that's ok, have the battery tested.

 

[mlpeloquin]

Unplug and check power connections, crimp lugs, at the back of your input connector. Then at all connections until you get to your breaker panel. All should be tight. Take a voltage meter and measure the voltage at the power pedistal from hot to neutral and then hot to ground. The voltages should be close. If the pedistal has good ground and the pedistal ground is connected to your chassis, then you should not have hot skin. Once the source is found and corrected, purchase an internally mounted Progressive surge protector. It will prevent power from getting through if there is an open ground or improper voltage. This will protect your rig and every device in it.

I forgot. Use a ohm meter to check your power cord. Power cords have been known to open up or become intermentent. Bend the ends while checking to see if the cord connectors have a loose connection. New connectors can be purchased and installed to replace the ones that came wit the cord.

 

[danemayer]

I have turned off breakers and pulled fuses one by one an none made a difference which leads me to believe the issue is isolated between the shore power and the inverter (or possibly the panel, whichever comes first). I was counting out the 110v line through the camper because the reading was so low but it looks like some think those connections are worth checking. I will do more prodding as recommended and get back with you all. Thank you for your input!

Some clarifications: inverters change 12V DC into 120V AC. Trailers come from the factory with Power Converters which change 120V AC into 12V DC. The Power Converter gets its power from an outlet controlled by a circuit breaker. So if you turned off each circuit breaker, you would have turned off the Power Converter.

Check the campground pedestal connections, the shore power cord connection to the trailer, and the connection on the back of the circuit breaker panel. If you're using any kind of adapters in the power path, get rid of them.

 

[Buckeye-travelers]

In thinking about this further, it may be that the battery issue and the small voltage reading on the frame are, at least in part, separate issues. I had them related in my mind as they are both electrical but the cure for stopping the reading on the frame is to unplug shore power. At the same time, the batteries are going dead to quickly when going dry camping so there would be no shore power connected. Unless this is a short somewhere that could affect both I may want to post about the battery drain in the 12v section. I will wait to hear some corroboration before cluttering the forum with far flung posts.
Thanks again for all of the help/responses
BT

 

[BuckeyeTravelers]

Same Login Name?

 

[Mattman]

Do you have a friend's power cord you can try or different shore power receptacle to see if the problem still remains?

 

[danemayer]

Same Login Name?

Almost the same

 

[mlpeloquin]

One more thing. Look at the grounding connection the batteries and the AC power ground is at. Make sure the connection to chassis is good. Unplug the AC. Remove the ground connections. Use sandpaper to clean the connection to chassis. Then put the grounds back.

 

[Bob&Patty]

Do as Mark suggested and add a star washer between the ground cable and the frame. You have an issue with the 120V system not the 12V system.

 

[JanAndBill]

All good advice. Have you tried changing pedestals?? Also , I didn't see it mentioned here but have you had the battery checked? A fully charged battery with no load should show 13.2 to 13.5 across the poles. A battery with a bad cell can read 13 or less when first charged but will discharge on its own

 

[macjj]

I had a similar issue on my 2002 BH. Wasn't noticed until I was working on some wiring in the rear. Found the problem with the Hubble 50 Amp twist connector for shore power. Although it seemed tight, as new it was tight. After making an extra twist effort, it seated correctly and problem gone. However, it has taken some time to loosen significantly for ease of removal


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