Extension Cord

Hi Wayne,

I know that the cord in my previous RV would "heat" when I did not pull it all the way out. I never bothered to measure the temperature--but from then on I always pulled it clear of the RV.

While it probably doesn't make much difference I believe that the shorter the cord to shore power, the better it is, provided such a cord can safely carry the number of amps being used.

I always use the 12 ga for cooling the fridge before a trip.

Wayne Dohnal wrote:

You should always pull the entire length of the trailer cord out whenever you plug in.

Why?

Verbatim from my owners manual: "WARNING: The power cord must be fully extended when in use and not left coiled in the electrical compartment or on the ground. If the power cord is left coiled, it may potentially create enough heat to melt its protective casing."

Why do the cords need to be unwound...

Two primary reasons, though one does not apply all that well to 30 amp cords.

First: All wires have multiple current ratings,, ONE of them is "Free Air"
Another is "Coiled" and yet another is "in a wall" This has to do with how well the wire can cool off when current heats it up. Somewhere I once saw a chart fo the coiled capacity but frankly, that was long ago. With the wires in a coil air does not circulate around the cable as well and it gets hotter.


Second is induction.. Coils offer "inductive" resistance (R sub j if I'm not mistaken, is the symbol) and like regular resistance I^2 R applies.. If you have one ohm of Rsub J and 20 amps, that's 400 watts of HEAT.

Even us not elect tech dummies know that a coiled 30 amp cord adds a little resistence, but we also know the is all factored in. I have never heard of anything so ridiculous as to completely uncoil a 30 amp cord before pluggin it into the generator, or anywhere else. Some of yous just love making RV'n complicated !
And I dint get old by being stupid either.

RJsfishin wrote:
Even us not elect tech dummies know that a coiled 30 amp cord adds a little resistence, but we also know the is all factored in. I have never heard of anything so ridiculous as to completely uncoil a 30 amp cord before pluggin it into the generator, or anywhere else. Some of yous just love making RV'n complicated !
And I dint get old by being stupid either.

Complicated? It's not really complicated, it takes me less than 5 seconds to pull the cord out. I did a mini risk assessment weighing the effort needed to pull the cord completely out (no effort) against the big warning printed in the manual, and it was a no brainer. No offense to you, but I'll take the manufacturers warning against your word any day.

Hi RJF,

That's why many of us "cut the cord". It made my (cold weather) life much much easier than trying extract a frozen cord through a small hole, let alone trying to stuff it back in at -30 c.

pianotuna wrote:
Hi RJF,

That's why many of us "cut the cord". It made my (cold weather) life much much easier than trying extract a frozen cord through a small hole, let alone trying to stuff it back in at -30 c.

-22F to us yanks. I makes the cord harder than a newly weds ...........

Never had a problem with keeping the 30A cord coiled and it's never got warm let alone hot. When I run the generator it all stays coiled inside the compartment. So if I plug it into the generator I should let it all hang out? When I'm plugged in at the house I use a smaller gauge extension. That would heat up before the larger 30A coiled up inside the compartment and it's never gotten warm either.

IMO the coiled up is not a huge deal unless you are running close to continuous max such as two air conditioners. Otherwise for normal use you are averaging half the rating or less.