Jayco RV Owners Forum
 


Reply
 
Thread Tools Display Modes
 
Old 05-19-2013, 02:08 PM   #1
Junior Member
 
Join Date: Feb 2012
Posts: 21
Shocking 5th wheel--Literally

All,

Just a word of warning.

It rained here in Kansas last night so everything is wet. We are headed to the lake for the week on Thursday so this morning I was out doing some prep work. I have a rack that I installed in my 5ver basement to store my fishing rods so they don't get damaged or tangled up. As I was putting the fishing rods into the rack I had to stick my head and upper torso into the storage compartment through a small back side storage door. As I did this there was rain water on the ledge of the door opening. This water wet my t-shirt which then transferred to the skin on my chest. I had on flip-flops so my feet were wet and I was standing on wet ground. Surprisingly I felt a pretty stiff tingle on my chest and on the side of my foot. I immediately thought that felt like an electrical shock. I got out my trusty volt meter and found that I had 60 volts from the frame of the 5ver to the wet ground. Needless to say I was mentally shocked to see this not mention the previous physical shock. I went to the RV.net forum and did a search for this issue and found a post that mentioned the possibility of the defective shore cord or a missing ground plug. I have my rig plugged into the sticks house power via a 50' extension cord. I went to look the cord over and found the male ground prong had broken off inside the 110 volt receptacle. I removed the cord and replaced it with a new out of the box cord and re-checked for the errant volts......GONE!!!

Hope this helps someone here.
__________________

__________________
2010 Jayco Eagle Super Lite 315RLDS
2013 GMC Sierra 2500HD 6.6L Duramax
2010 Pit Bull Terrier (Jake)
2010 Camping Nights 45
2011 Camping Nights 70
2012 Camping Nights 144
2013 Camping Nights 49
allen8106 is offline   Reply With Quote
Old 05-19-2013, 02:36 PM   #2
Site Team
 
norty1's Avatar
 
Join Date: Jan 2011
Location: Charleston, SC
Posts: 12,032
Sure glad you found it. An ungrounded extension cord can be dangerous in a RV.
__________________

__________________
Moderator
2011 351RLTS Eagle, Mor/Ryde suspension & pin box
06 F350 Lariat PSD, SRW, LB, CC, EGR delete kit, 16K DrawTite hitch, Timbrens, TST TPMS

Can't find what you're looking on JOF? Try:Jayco Owners Forum Custom Google Search
"It's easier to fool people than to convince them that they have been fooled." - Mark Twain
norty1 is offline   Reply With Quote
Old 05-19-2013, 03:19 PM   #3
Senior Member
 
RVhiker's Avatar
 
Join Date: Dec 2010
Posts: 1,253
Before we installed an EMS, we used a simple polarity tester. Cheap, and it tells you missing grounds or reversed hot/neutrals; it's available at Lowe's or Home Depot. Cheap Outlet Tester
__________________
There's lots of advice and information in forums... sometimes it is correct. For example, all of my posts are made by a political appointee who got the job as a reward for contributions to my diesel bill.

2011 Jayco 28.5RLS; 2008 Chevy Duramax; Pullrite Superglide Hitch

RVhiker is offline   Reply With Quote
Old 05-19-2013, 04:55 PM   #4
Senior Member
 
lx22f/c's Avatar
 
Join Date: Feb 2012
Location: Friendswood
Posts: 917
Shocking 5th wheel--Literally

Wow glad you found the problem.
lx22f/c is offline   Reply With Quote
Old 05-20-2013, 04:31 AM   #5
Senior Member
 
tinlizzie23's Avatar
 
Join Date: Sep 2011
Location: Luray, VA (central Shenandoah Valley of VA)
Posts: 1,416
If my understanding is correct, an RV electrical system is very different from your house system. In the house, both ground and neutral wires are connected together on the same buss inside your service panel, while in an RV they are NOT connected. So if you lose your ground in an RV, there is a strong possibility that you can get voltage applied to metal parts of the RV, and if you touch them while you yourself are grounded, you get a shock. Perhaps someone more familiar with an RV system can explain it better than I, but I feel it is mandatory to check for proper ground every time we are camping.
__________________
2003 Ford F-350 V-10 Crew Cab 4WD Long Bed
2004 Jayco Designer Medallion 29 RLTS 5th wheel
Bill, Gayle, and Mindi (dachshund)
Retired at last !

Nothing is foolproof to a sufficiently talented fool.
tinlizzie23 is offline   Reply With Quote
Old 05-20-2013, 06:47 AM   #6
Senior Member
 
RVhiker's Avatar
 
Join Date: Dec 2010
Posts: 1,253
I think that the neutral and ground of the 120v system in an RV are required not to be bonded; the neutral and ground at the pedestal are bonded. According to Progressive industries (from an instruction sheet for an EMS):

"RV wiring is different than the wiring found in homes; the neutral and ground conductors are isolated in the RV, unlike in a home where they are tied together at the service panel. The reason is: homes have a bonded ground system, whereas RV’s do not. Therefore, never bond the neutral and ground together for any reason. This will create a ground fault condition, and may result in electric shock and/or a fire hazard."

I believe that one reason for this RV wiring requirement is this: assume that the hot and neutrals are reversed; assume a defective ground connection--- then you have 120 volts at the frame and other metal parts of the RV. You touch your RV frame or metal parts standing on wet ground, and POOF!
__________________
There's lots of advice and information in forums... sometimes it is correct. For example, all of my posts are made by a political appointee who got the job as a reward for contributions to my diesel bill.

2011 Jayco 28.5RLS; 2008 Chevy Duramax; Pullrite Superglide Hitch

RVhiker is offline   Reply With Quote
Old 05-20-2013, 07:03 AM   #7
Senior Member
 
Join Date: Jun 2012
Location: Long Island, NY
Posts: 627
Quote:
Originally Posted by allen8106 View Post
All,

Just a word of warning.

It rained here in Kansas last night so everything is wet. We are headed to the lake for the week on Thursday so this morning I was out doing some prep work. I have a rack that I installed in my 5ver basement to store my fishing rods so they don't get damaged or tangled up. As I was putting the fishing rods into the rack I had to stick my head and upper torso into the storage compartment through a small back side storage door. As I did this there was rain water on the ledge of the door opening. This water wet my t-shirt which then transferred to the skin on my chest. I had on flip-flops so my feet were wet and I was standing on wet ground. Surprisingly I felt a pretty stiff tingle on my chest and on the side of my foot. I immediately thought that felt like an electrical shock. I got out my trusty volt meter and found that I had 60 volts from the frame of the 5ver to the wet ground. Needless to say I was mentally shocked to see this not mention the previous physical shock. I went to the RV.net forum and did a search for this issue and found a post that mentioned the possibility of the defective shore cord or a missing ground plug. I have my rig plugged into the sticks house power via a 50' extension cord. I went to look the cord over and found the male ground prong had broken off inside the 110 volt receptacle. I removed the cord and replaced it with a new out of the box cord and re-checked for the errant volts......GONE!!!

Hope this helps someone here.
I had the same thing happen to me on my old motorhome. The 30 to 15 amp adapter had the ground prong broken off. I was washing the awning one day and was getting shocked as I sprayed the hose and touched the awning support.

Stay safe out there !
__________________
Thanks,
Brian

TV = 2006 F-350 CC DRW 6.0
TT = 2018 Wildwood 31KQBTS
TT = 2007 Jayco Jay Flight 27bh - SOLD
Macrosill is offline   Reply With Quote
Old 05-20-2013, 08:10 AM   #8
Senior Member
 
VicS1950's Avatar
 
Join Date: Apr 2013
Posts: 517
Quote:
Originally Posted by allen8106 View Post
All,

Just a word of warning.
...

I removed the cord and replaced it with a new out of the box cord and re-checked for the errant volts......GONE!!!

Hope this helps someone here.
You may have treated the symptom, not the disease.

A couple quick comments. First, you really should be plugged into a 15 or 20 amp GFI protected receptacle with your adapter. Perhaps there is a GFI, but the leakage current you felt through your wet shirt never exceeded 5 mA to trip the GFI. GFI's protect against lethal shock, but not all shocks. Perceptible current can be less than 5 mA.

If the receptacle is GFI protected and didn't trip you should test it using the test button on the breaker or on the protecting receptacle. (A feed through GFI receptacle could be used upstream from the receptacle you are plugged into.

Within the RV system proper the ground and neutral should never, ever be bonded together. That can set up some really dangerous conditions. The neutral should only be bonded at specific main power system panels, never in an RV.

In the situation described where the now established ground has drained off the voltage you likely still have an electrical problem within the camper which could come back to bite you. The ground wire is not required to keep the TT frame at ground potential in a properly operating 240/120 volt electrical system. The current carrying parts of the system should be completely isolated from the RV frame/metal parts. You may still have a problem somewhere which is leaking voltage to the trailer frame.

Keep people away from the trailer as you test as I outline here.

I would suggest that you turn off all your trailer 120 volt trailer breakers, connect the trailer using your ungrounded broken cord and check for the 60 volts on the frame to ground. If you find the 60 volts is back then you have leakage or damaged insulation somewhere in the main cord system.

If the 60 volts is not there then unplug the trailer cord and have someone enter the trailer to switch breakers on and off. Plug the trailer back into the receptacle. Check again for the 60 volts to ground. If not there continue to monitor for the 60 volts and have the person inside switch individual breakers on and off until the 60 volts comes on. Test with all breakers even after you discover the bad circuit because you could have multiple problems. Once you isolate down to one breaker then you can continue to test whatever is plugged into the circuit by unplugging devices. Some electronics design can impose a voltage on the ground circuit.

Anyway, you should not just depend upon the ground wire to drain off the leakage you have in your trailer.

There is some very good information about RV electrics to be found here:

http://www.noshockzone.org/

Mike Sokol does a great job explaining things.

Please follow up on troubleshooting for problems with your trailer electrical system. Not all (almost none?) 30 amp recepatacles in campground power pedestals have GFI protection so you could have problems in the future should the grounding be lacking somehow. vic
__________________
Double Secret Probation
VicS1950 is offline   Reply With Quote
Old 05-20-2013, 02:46 PM   #9
Junior Member
 
Join Date: May 2013
Posts: 13
Quote:
Originally Posted by VicS1950 View Post
You may have treated the symptom, not the disease.
Anyway, you should not just depend upon the ground wire to drain off the leakage you have in your trailer.
There is some very good information about RV electrics to be found here:
http://www.noshockzone.org/
I'm Mike Sokol, the author of the NoShockZone.org website mentioned here. Hey Vic, thanks for posting my link.

Vic is correct in that there should be 100% isolation of the frame of the RV from the incoming 120-volt line, but sometimes appliances get a little "leaky" from age and vibration. If there IS any sort of leakage to the chassis, then the lack of a solid safety ground on the RV's shore power connection will drag the RV's skin voltage up towards 120-volts. However, it should be noted that some "double isolated" appliances (without a ground pin on their power cord) will quite normally rise up to 60-volts AC, which is half of the 120-volt line potential. I've read the "skin" voltage of slow cookers (for instance) at 60 volts, but there was way less than 1 mA (milliamp) of current available, so you would never feel a shock, even though you're providing the ground path. But I never really trust that sort of situation because worn or overheated insulation can turn that safe "high-impedance" hot-skin, into a dangerous "low-impedance" hot-skin without any warning.

And yes, you really should be plugged into a GFCI outlet, but only the 20-amp campground outlets are required to be a GFCI. And note that you're supposed to test all GFCI breakers once a month for proper tripping, because age or voltage spike can render them useless.

One final note.... a simple surge strip like you can buy for $10 at a big box store will cause a certain amount of leakage to the safety ground through the MOV devices. So plugging a surge strip into an open ground power connection will cause a high-impedance hot-skin with 2 or 3 mA of current. Crazy, but true.

Mike Sokol
mike@notshockzone.org
www.NoShockZone.org
jmsokol is offline   Reply With Quote
Old 05-21-2013, 03:36 PM   #10
Junior Member
 
Join Date: May 2013
Posts: 13
Quote:
Originally Posted by RVhiker View Post
I think that the neutral and ground of the 120v system in an RV are required not to be bonded; the neutral and ground at the pedestal are bonded. According to Progressive industries (from an instruction sheet for an EMS):

"RV wiring is different than the wiring found in homes; the neutral and ground conductors are isolated in the RV, unlike in a home where they are tied together at the service panel. The reason is: homes have a bonded ground system, whereas RVís do not. Therefore, never bond the neutral and ground together for any reason. This will create a ground fault condition, and may result in electric shock and/or a fire hazard."

I believe that one reason for this RV wiring requirement is this: assume that the hot and neutrals are reversed; assume a defective ground connection--- then you have 120 volts at the frame and other metal parts of the RV. You touch your RV frame or metal parts standing on wet ground, and POOF!
You are correct that the Neutral and Ground is separated in all RV electrical panels, and also correct that the reason is so that a swapped Neutral and Hot in a campground won't cause a hot-skin condition. But RV's are wired a lot more like your house than most people realize. In fact, RVs are wired exactly like a home SUB-panel, where the ground and neutral wires are kept separated and only bonded together at one point in the SERVICE panel, where they're tied together with the ground rod. I think of this entrance point as the G-N-E (Earth) point, and it creates an artificial "ground plane" that's supposed to supply the fault current path in the event that a wire shorts to a chassis somewhere. Most consumers aren't aware that the "ground rod" really isn't a very good "ground" to begin with, since they will normally have 25 to 100 ohms impedance to earth. So NEVER think that a ground rod will protect your RV from a hot skin if you don't have a solid "safety ground" wire connected back to the main service panel. A so called "ground rod" is only there for lightning protection, and to keep the system voltage of your building ground close to earth potential. It's has too high of an impedance to trip a circuit breaker in the event of a fault, though it should be enough to trip any GFCI. But GFCI's are only required on 20 amp campground outlets, and most RV owners quickly learn to use a 30-to-20 amp adapter to get rid of random GFCI tripping. Know that GFCI's rarely trip without a reason, so bypassing one with an adapter is a bad idea. You should find out what's actually tripping the GFCI rather than simply doing a workaround.

Mike Sokol
mike@noshockzone.org
www.noshockzone.org
__________________

jmsokol is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Virginia State Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -6. The time now is 12:03 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 2002-2016 Social Knowledge, LLC All Rights Reserved.