DIYbanter - View Single Post

[email protected]

On Mon, 21 Jan 2008 00:42:00 +0000 (UTC), (Don
Klipstein) wrote:

In article , Ralph Mowery wrote:

wrote in message
. ..
On Sat, 19 Jan 2008 11:12:10 -0600, Steve IA
wrote:

ransley wrote:

Get a clamp on amp meter that goes to 0,01 amp, not found a stores but
electric supply houses, a 35$ Greenlee is good. Clamp on each circut
on your panel to check consumption and compare it to what is plugged
in by their watt ratings, then check with everything off, then
unplugged. You might find a direct short to ground.

Can two extension cords, plugged together and covered with ice and snow
cause a direct short without breaking the circuit breaker?

I'm a farmer and every winter I have these livestock tank heaters
connected by extension cords. I often plug 2 cords together. This
year we had a bad ice storm come early. I normally try to lift the
cords out and on top of the snow, and also usually tape a plastic bag
around the plugs. This year bad weather came early and the ice/slush
froze and all cords are buried. Where they plug together, I recently
found holes melted in the snow. Obviously there is some leakage.
Yet, these are all plugged into GFI outlets. I highly doubt this
would amount to much loss though.

What you are seeing with the plugs is probably just a loose or bad
connection. It may not even be worth worring about. If it was much
loss to the ground , the GFI would trip. It only takes a few miliamps of
leakage to trip the GFI. Not enough to be noticiable on the electric
bill, Maybe a dime a month.

Heating at plugs is usually from partial breakage of the conductors due
to metal fatigue. One common cause is pulling on the cable rather than
the plug to unplug them. Also, pulling on cords to move them while they
are plugged to others, to the extent as to move the connected cords, may
cause this.

Plugs warming up can be a fire hazard. See if they warm up
significantly, or there is only negligible heating that may be a normal
amount from contact resistance. If plugs/sockets or wire within a couple
inches of the them gets noticeably warm, or warmer than the cable more
than a few inches from the ends, then it is good to cut off the ends (and
a few inches of cable) and replace the plugs/sockets. (Or replace the
whole cord.)

A few milliamps leakage from hot to ground and several milliamps more
from hot to neutral (which is closer than ground) can ammount to a good
watt - and I see that sometimes melting snow in a localized area over a
day. However, I think warm plugs/sockets are more likely to warm up from
extra resistance from contact resistance, cheap connection of wires to
plugs/sockets, or wires with some strands broken at the plugs/sockets due
to metal fatigue.

- Don Klipstein )

Thanks

There is likely a bit of heating on these plugs no matter what,
because these tank heaters are 1000W. (or 500W on the smaller tanks).
I am running 12 of them right now. I know my electric bill will panic
me this month, but the animals got to drink. I tend to use the
smaller 500W tanks as much as I can, but in the severe cold we are
having I use anything that wont freeze.

I'm not too worried about a fire starting in the middle of an icy
lawn in January.