rvupgradestore.com Composet Products Fridge Defend
RV Life Magazine RV Park Reviews RV Trip Wizard

Author Topic: This is disturbing... (calling all electricians)  (Read 4192 times)

JeffPax

  • ---
  • Posts: 100
This is disturbing... (calling all electricians)
« on: December 18, 2013, 09:55:55 AM »
Noticed something new from the window :-\ So I went outside to investigate. Unfortunately, my suspicions were confirmed. This can't be good...
Not sure when this occurred. Been having electrical issues lately, but it's been almost 2 weeks since the j-box fire underneath so I don't know if they are related. I think this is newer, like in the last 24 hours, but I can't be sure. I have a surge protector on the 50A CG supply and the CG is wired correctly. Let's hear from experts.

Molon Labe
2006 GMC Duramax Crew
2005 Fleetwood Regal Prowler AX6 385FKQS

JeffPax

  • ---
  • Posts: 100
Re: This is disturbing... (calling all electricians)
« Reply #1 on: December 18, 2013, 09:57:36 AM »
The hole is deep (you can't tell in the pic). I have wrapped it in electrical tape to keep the water from getting to the internals.
Molon Labe
2006 GMC Duramax Crew
2005 Fleetwood Regal Prowler AX6 385FKQS

Punomatic

  • ---
  • Posts: 668
    • Life in Black and Blue
Re: This is disturbing... (calling all electricians)
« Reply #2 on: December 18, 2013, 10:19:52 AM »
Looks like you have a loose connection inside the plug that is arcing and burning the plastic.  Get a new plug. Remove the old plug and any wire that has burned insulation (yes, this will make the cord a little shorter, but not much). Install the new plug, and you should be good to go.  I had a similar problem a few years ago. I suspect the weight of the cord hanging on the plug eventually loosens the wires.  I would also suggest dismantling the plug, say, annually and checking your connections. If you are uncomfortable with any of this process, remove the cord and take it to a competent electrician. Happy travels.
2016 Riverside White Water Retro 195
2014 Nissan Titan SL Crew Cab
DW and me

SeilerBird

  • ---
  • Posts: 14795
Re: This is disturbing... (calling all electricians)
« Reply #3 on: December 18, 2013, 10:25:43 AM »
Obviously the plug needs to be replaced. However there is more. The breaker that controls the 50 amp CG outlet is obviously defective. The breaker should have tripped long before the plug started melting. You need to replace that breaker also. It is really up to the CG owner to do the job but if you are going to be there awhile I would think about doing the job myself.

JeffPax

  • ---
  • Posts: 100
Re: This is disturbing... (calling all electricians)
« Reply #4 on: December 18, 2013, 10:28:01 AM »
Thanks Puno! I figured somebody had seen this before. I am a carpenter by trade so I can get around in the electrical world okay and the plumbing world a little better, so I will get it done. Was already on ebay looking for a new plug. Mainly wanted to know if this could indicate anything else or be related to the previous burn.

Seiler, Understand, I will let the CG owner know right away. Thank you!
Molon Labe
2006 GMC Duramax Crew
2005 Fleetwood Regal Prowler AX6 385FKQS

Harvard

  • ---
  • Posts: 208
Re: This is disturbing... (calling all electricians)
« Reply #5 on: December 18, 2013, 11:36:30 AM »
Obviously the plug needs to be replaced. However there is more. The breaker that controls the 50 amp CG outlet is obviously defective. The breaker should have tripped long before the plug started melting. You need to replace that breaker also. It is really up to the CG owner to do the job but if you are going to be there awhile I would think about doing the job myself.

In all likelihood there is a bad connection, which is a point of high resistance, that is generating the hot spot AND as such IS NOT DRAWING any extra current. Those circumstances would not trip a normal circuit breaker.

In Canada, it is now mandatory to service bedroom duplex plugs with "Arc Fault Circuit Interrupter" (AFCI) breakers to catch these kind of "high resistance" hot spots that do NOT draw extra current that would trip a normal "current limiting" circuit breaker.

SeilerBird

  • ---
  • Posts: 14795
Re: This is disturbing... (calling all electricians)
« Reply #6 on: December 18, 2013, 11:41:45 AM »
I give up
« Last Edit: December 18, 2013, 12:46:39 PM by SeilerBird »

Harvard

  • ---
  • Posts: 208
Re: This is disturbing... (calling all electricians)
« Reply #7 on: December 18, 2013, 12:09:37 PM »
If there is a bad connection that is heating up the plug then it is drawing extra current. That is why it melted. The breaker is bad since it is not doing it's job properly.

If extra resistance is inserted in a series circuit (as in a bad connection) the current in the circuit is reduced. Either that or Mr Ohm was wrong. :)  When this unintended additional resistance is larger then the normal load resistance excessive (and destructive) heat will be generated across the bad connection.

Gary RV_Wizard

  • Forum Staff
  • ---
  • *
  • Posts: 69991
  • RVer Emeritus
Re: This is disturbing... (calling all electricians)
« Reply #8 on: December 18, 2013, 12:13:17 PM »
Quote
The breaker is bad since it is not doing it's job properly.

I have to disagree, Tom. With a partially broken wire or high resistance due to corrosion, a lot of heat will be generated without ever exceeding the 50A breaker rating. The problem is that the internal connection can no longer handle normal amperage, which is probably in the 25-35 amp range. The breaker on the power pole likely never even got close to its trip rating.
Gary
--------------
Gary Brinck
Summers: Black Mountain, NC
Home: Ocala National Forest, FL

Great Horned Owl

  • ---
  • Posts: 1487
  • Lake county, IL
Re: This is disturbing... (calling all electricians)
« Reply #9 on: December 18, 2013, 12:35:13 PM »
Obviously the plug needs to be replaced. However there is more. The breaker that controls the 50 amp CG outlet is obviously defective. The breaker should have tripped long before the plug started melting. You need to replace that breaker also. It is really up to the CG owner to do the job but if you are going to be there awhile I would think about doing the job myself.

Probably not. A localized hot spot like that is caused by a high resistance contact inside of the plug. It very likely did not draw any extra current, and should not have tripped the breaker.

Joel

Joel & Dorothy
Retired electronics engineer. Avid photographer, paddler & birder.
2011 Silverado 2500HD, Duramax, 4x4,crew cab, 8' bed
Palomino Puma 253-FBS  27' 5th wheel
1994 19' Class B Horizon / Chevy

Great Horned Owl

  • ---
  • Posts: 1487
  • Lake county, IL
Re: This is disturbing... (calling all electricians)
« Reply #10 on: December 18, 2013, 12:44:58 PM »
If there is a bad connection that is heating up the plug then it is drawing extra current. That is why it melted. The breaker is bad since it is not doing it's job properly.

Tom, I was an engineer at UL for 10 years. Among other things, I tested plugs. If there is a loose connection inside the plug, the heating will oxidize the wire and cause the resistance to keep going up. Ultimately, the resistance can be as much as 5 or 10 ohms. The power being dissipated is I2xR. At 10 amps, that is 1000 watts. Easily enough to melt (or even ignite) the plug without being even close to tripping a 15 amp breaker much less than a 30 amp.

Joel
Joel & Dorothy
Retired electronics engineer. Avid photographer, paddler & birder.
2011 Silverado 2500HD, Duramax, 4x4,crew cab, 8' bed
Palomino Puma 253-FBS  27' 5th wheel
1994 19' Class B Horizon / Chevy

bucks2

  • Guest
Re: This is disturbing... (calling all electricians)
« Reply #11 on: December 18, 2013, 01:12:17 PM »
Uhm...... UNPLUG THE CORD NOW! That is an extreme fire hazard! I don't mean to frighten anyone but many many fires start from exactly that cause. Ordering a plug on the internet is not the answer. Plugs like that oxidize, create heat and eventually the heat finds something that will burn. I'll bet you don't use contact cleaner and clean both sides of that plug often do you? In the marine environment we do it every 6 months.

Gary and Owl are right, you have a resistance heater inside your electrical plug,it won't trip the breaker.

If you don't believe me, go inside and turn on a few high draw items then come back out and watch the red glow develop inside the plug. That is a fire waiting to happen.

Ken

JeffPax

  • ---
  • Posts: 100
Re: This is disturbing... (calling all electricians)
« Reply #12 on: December 18, 2013, 02:31:04 PM »
Okay, no local suppliers had it, and could only get it by tomorrow. I ordered it Amazon prime, upgraded to next day delivery. It will arrive tomorrow same as local suppliers but it will come to my door rather than run into town to get it.

bucks2: I have not cleaned the contacts. On this connector, they are inaccessible as it is the female plug. The male connectors in the rv side receptacle are bright shiny clean so it never occurred to me to take this apart and go to the internals for a cleaning.

We will be running on batteries until repair is made.
Molon Labe
2006 GMC Duramax Crew
2005 Fleetwood Regal Prowler AX6 385FKQS

bucks2

  • Guest
Re: This is disturbing... (calling all electricians)
« Reply #13 on: December 18, 2013, 09:11:01 PM »
Good choice on the plug ordering and delivery. Excellent choice on using batteries.

To clean the contacts spray the cleaner on and into both sides (male and female) and then insert, twist and take the plug back out several times. The cleaner will loosen the corrosion and the mechanical action of the plug prongs rubbing against each other will take it off. Spray the little wand up into the plug, with the plug end pointing down to flush the crud out.

ken

JeffPax

  • ---
  • Posts: 100
Re: This is disturbing... (calling all electricians) FIXED!
« Reply #14 on: December 19, 2013, 02:16:39 PM »
I removed the plug, cut the melted portion away with the multi tool so I could remove the cover. Upon inspection, I found the black wire inserted only part way, and the screw was tight. Only about 1/4 of the stranded wires were crushed in the clamp. I was able to pinch it and pull it out with no effort.

As a side note, was up every two hours charging the batteries (new in March) from my pickup. It appears I have a 12V problem as well. *sigh* When it rains it pours and this winter, which isn't even here yet, sucks!

Molon Labe
2006 GMC Duramax Crew
2005 Fleetwood Regal Prowler AX6 385FKQS

John Canfield

  • Forum Staff
  • ---
  • *
  • Posts: 13053
    • Jane and John's Internet Home
Re: This is disturbing... (calling all electricians)
« Reply #15 on: December 19, 2013, 05:59:42 PM »
Tom, I was an engineer at UL for 10 years. Among other things, I tested plugs. If there is a loose connection inside the plug, the heating will oxidize the wire and cause the resistance to keep going up. Ultimately, the resistance can be as much as 5 or 10 ohms. The power being dissipated is I2xR. At 10 amps, that is 1000 watts. Easily enough to melt (or even ignite) the plug without being even close to tripping a 15 amp breaker much less than a 30 amp.

Joel
Exactly.
--John
2005 Horizon 40AD, 2006 Jeep Rubicon Unlimited
Our Horizon projects
Our weather