Shore Power Cord Safety

Rustic Eagle · 06-02-2011, 07:08 AM

I was told years ago that the 30amp/50amp RV shore power cord can heat up depending on the load on the cord, so I have always pulled all of my cord out of the TT housing, even if I don't need the total length. I don't coil the excess of cord on the ground either, I just snake it around.

The longer the cord, the potential for heat build-up increases do to the additional resistance. The setups that scare me are where a camper uses a smaller extension cord added to their RV shore line cord.

Be careful out there.

Bob

coalrig · 06-02-2011, 07:22 AM

Yup seen them go up in flames, 50 to 30 setup on my trailer, using too much power at the time, poor cord, washer dryer going and the airconditioning.

I get two years out of a power cord.

David472 · 06-02-2011, 08:22 AM

Another reason for pulling out all the cord;
often the converter occupies the same space as the cord storage area. By pulling out all the cord, you are opening out more cooling space for the converter.

Denise · 06-02-2011, 09:28 AM

Had never thought about this. Thanks

Terry · 06-02-2011, 11:05 AM

Ok - I am starting to talk over my head here - but I had also understood that with A/C and coiling a cord it could cause some magnetic interference. Although I suspect this is somewhat small, I have enough of a difficulty using my cell phones or walkie talkies inside a big metal box there is no reason to make things worse.

Maybe it is this magnetic field that is created that also generates the heat? Dont know...but I always pull mine all the way out as I feel it is the safest way to operate.

David472 · 06-02-2011, 11:31 AM

Some background info;
Every conductor has some amount of resistance to it. Larger diameter conductors have less resistance. The current squared times the resistance is the power lost in the conductor. This power loss shows up as heat. This formula is used to determine the recommended conductor gauge size for a given application. Thirty amp cables need to be 10 gauge or larger, to be safe to use in a confined area.

The metal sides of your trailer form a Faraday shield, which will impede the passage of radio signals, such as cell phone etc. The coiled 30 amp cable would have a very weak magnetic field, and not really a factor for cell phones, unless you hold the phone against the coiled cable.

Hope this helps with understanding.

Terry · 06-02-2011, 04:58 PM

Haha...yeah...my wife always looks at me strange when I get frustrated at the signal and I tell her I am in a Faraday Cage - she has no idea what that means but knows it is not good! The field is probably weak, but given my cell phone usually is too...every little bit helps...lol....it also cant be good for that Jensen radio which as well all know has such great reception..

**Crabman** · 06-02-2011, 05:22 PM

I must say this is something I never considered and have always pulled out only what was necessary. I guess I will pull it all they way out from now on to be safe. When hooked to shore power just to keep up the battery, not running much, would it still be necessary to pull it out?

82corvette · 06-02-2011, 05:51 PM

I once had a retractable extension cord hooked up to a battery charger without pulling it out all the way. After seeing it catch fire I always pull my camper cord all the way out & let it snake out on the ground.

Rustic Eagle · 06-02-2011, 06:02 PM

Quote:

Originally Posted by Crabman

snip......When hooked to shore power just to keep up the battery, not running much, would it still be necessary to pull it out?

Lee,

IMO if the only load on the 30amp cord is the TT battery charger (converter/charger), I wouldn't think this would be a potential heat issue.

But remember, I'm more comfortable with grease, wrenches, and sludge hammers!

Bob

**Crabman** · 06-02-2011, 06:17 PM

Yeah even I can smear a little grease, or operate a sledge hammer (but not for very long!)

David472 · 06-02-2011, 07:31 PM

Quote:

Originally Posted by Crabman

snip.....When hooked to shore power just to keep up the battery, not running much, would it still be necessary to pull it out?

Well, that's what I do. When at home, want to charge the battery or other light loads, I don't pull the cord all the way out. If you're worried about it, just feel the converter box. If it's warm, but you are able to hold your hand against it, you're okay. If touching it is uncomfortable, then you know what to do.

skymutt · 06-03-2011, 11:14 AM

If a 30Amp cord went "up in flames" while pluged into a 30Amp service (or a 50A into a 50A service) something with the service was WAY wrong. The CB shoulld have popped well before any danger of a fire.

AR Banjo · 06-03-2011, 11:41 AM

We had something like this happen in Iraq several times with cheap Chinese-made extension cords/power strips (on 220). If you didn't uncoil the cord (which came coiled with twist ties holding it together) before use, after a while the coating/insulation would begin to melt. If you didn't catch it then, it would eventually start to burn. With flames!

After seeing this, I have always pulled out my shore power cord all the way--just to be safe. It may never happen to my TT, but it only costs a few more seconds to pull it out all the way.

David472 · 06-03-2011, 06:57 PM

Mentioning Chinese power cords.......there are some power cords out there (of many application types), which say they are 10 gauge (or other gauge), but due to high copper prices, the conductor is actually one or two gauges smaller than required by spec. The only way to tell for sure is expose the copper and measure the conductor diameter. A secondary check would be to touch the cable when under a 30 amp load. A true 10 gauge wire will be cool to the touch with 30 amps running thru it.

Terry · 06-03-2011, 08:18 PM

Quote:

Originally Posted by Crabman

I must say this is something I never considered and have always pulled out only what was necessary. I guess I will pull it all they way out from now on to be safe. When hooked to shore power just to keep up the battery, not running much, would it still be necessary to pull it out?

I would not hesitate to do that overnight to keep the battery charged and fridge running, but if I was going to run anything like the A/C or Water Heater - I would pull it all the way out. I also pull mine all the way out when it is storage and plugged up.

mustang · 06-04-2011, 06:26 AM

on our last outing we we disconnected our power cord the prongs were so hot they burned the skin. We assumed that because the campground was full and it was hot out that the campground power could not keep up with the demand or is this common for TT cords to heat up under a load of AC, Fridge etc. Is there anything we can purchase to help protect our TT from the cord overheating

David472 · 06-04-2011, 07:53 AM

Quote:

Originally Posted by mustang

on our last outing we we disconnected our power cord the prongs were so hot they burned the skin. We assumed that because the campground was full and it was hot out that the campground power could not keep up with the demand or is this common for TT cords to heat up under a load of AC, Fridge etc. Is there anything we can purchase to help protect our TT from the cord overheating

Excessive heating like that is a sign of a poor connection. If you only experienced that in the one CG, then it's possible the poor connection was inside the CG's pedistal recepticle, rather than inside your plug. One possibility is the terminals inside the CG's recepticle had become corroded from weather exposure. In that case, plugging and unplugging multiple times may help the condition. Electrical supply stores sell a grease called Penetrox meant for applying to electrical terminal connections to aid conductivity. The multiple pluging in and out, plus applying the grease to your cord prongs, is a possible quick fix. The best fix would be for the CG to replace the corroded terminal. These are all educated guesses on why your cord prongs were hot.

As a side note: routine preventive maintainence for industrial electrical panels, is to take infared pictures looking for hot connections. If found, steps are taken to correct the poor connection.

Seann45 · 06-04-2011, 07:56 AM

Quote:

Originally Posted by mustang

on our last outing we we disconnected our power cord the prongs were so hot they burned the skin. We assumed that because the campground was full and it was hot out that the campground power could not keep up with the demand or is this common for TT cords to heat up under a load of AC, Fridge etc. Is there anything we can purchase to help protect our TT from the cord overheating

I dont know if this will stop that.. BUT I would not plug into a campground without one of these inline..

http://www.campingworld.com/shopping...rge-guard/2279

expensive YES but well worth the price...

Terry · 06-08-2011, 10:23 AM

My plug melted pretty good about a year ago. It was in a very old pedestal and I can only assume it was a bad connection. The rubber melted some and the prongs were discolored. I purchased an EMS, but that probably wont be a fix-all...it just happens - which is why I always carry an extra plug with me.

One thing I do - I carry a 50 to 30 adapter. Whenever I am at a 50 spot, I use it instead. I figure it is less often used and will be in better shape.

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