I was using a circular saw to cut some 4x8 sheets of 5/8" fiberboard (not
MDF, the less dense stuff). Halfway through my first cut of the day, the
blade wound to a stop and the saw appeared dead. Checking the outside
outlet I was plugged in to I found a huge black scorch above it and half of
the plug was melted. One of the prongs melted off and is stuck in the
socket. This outlet is located outside the house but underneath a protected
entryway. The house is 10 years old and in good repair.
The saw is a 2hp 10amp. The cord is a heavy gauge (was) in good condition,
40 feet long. Not sure the exact gauge of the cord but it's thicker than
the average outside extension cord.
After this incident I plugged the saw into a different outlet (GFCI
protected in the garage) with a shorter but lighter gauge cord and proceeded
without incedent to rip my five 4x8 sheets. The GFCI never tripped.
Is a 40 foot extension cord too long to run a 10amp saw with? If that's not
it, does anyone have any thoughts on what the problem might be? Thanks for
Four thoughts come to mind as to what may have caused this:
1. Loose connections inside of the plug of the extension cord.
2. Loose connections on the receptacle.
3. Water on or inside of the outlet.
4. Worn out receptacle was not making good contact with plug.
It could also have been any combination of the four. I think it is odd that
it happened so quickly on your first cut.
I install commercial grade 20 amp outlets in my house (also have 20 amp
circuits). These cost $3 each as compared with 69 cents, but I never have
such problems with them.
Also for construction work; saws, compressors, etc. I get the largest gauge
extension cords I can buy. 12 or 10 ga. (Home deplete your bank account has
these [Home Depot])
And if replacing plugs on an extension cord or appliance, I get commercial
grade heavy duty plugs which also have a screw down wire clamp.
And I *never* pull a plug out of the socket by pulling on the wire. This can
damage the connection between the wire and the plug.
Basically I don't have any trouble.
Note: If the outlet which got fried is a 15 amp circuit, replace it with a
15 amp commercial grade outlet, not a 20 amp outlet. Commercial grade
outlets have much better contact with the prongs on the plug. So the plug
will not be warm to the touch after use.
"Barry" wrote in message
Most likely you had the right equipment. Probably what happened was
that your outlet had a high resistance connection on it. If it was
wired as a poke and stab, this would be a likely cause, although a
loose wire on a loose screw could also give you high resistance.
The outlet sat there for years with no problem, but then you plugged
in your saw and started drawing high current. The high resistance
connection is going to heat up more and more and you saw the result.
Replacing with a high quality outlet and turning those screws tight
(with the power off) should solve the problem. Also, heed what the
previous poster said. Buy good, heavy duty extension cords. 10 ga is
best, minimum should be 12 ga.
I also *do not* wire my outlets by sticking the wires in the holes in the
back. I use needle nose plyers to make a round curve in the stripped wire,
then screw the wire down tight on the outlet.
"Beachcomber" wrote in message
Just a bad connection--probably the plug in the
socket or a short at the plug end of the cord.
For 40 feet you probably want to use at least #14
cord on that saw and you really don't want any
cord less than #16 for any distance. Course it
isn't 2 hp since it is only 10 amps (probably
closer to 1 hp, maybe even 1.25 hp).
I prefer to use a 12 gauge extension cord for
anything drawing that many amps, but sometimes use
a smaller gauge. You can buy a 50 foot 12 gauge
extension cord for $16 when Harbor Freight has
them on sale. (or if you hate Harbor Freight
enough, go to Lowes or Home Depot and buy the same
cord (same color same manufacturer) for $50 or more.
Ran into a similar problem daisy-chaining the 5-buck orange cords to use a
leaf blower out back. Didn't blow up, but the connectors were getting warmer
than I like. Went to Sams Club, and paid 30 bucks for their 100-foot
'contractor grade' (whatever that means) 12-3, with a triple tap (clear,
with an LED) on the downstream end. Gawd-awful yellow with a blue stripe,
and it only wants to roll up one way, but what do you expect from cheap
China junk? If I was still making a living with power tools, I'd pay the
money for a quality cord, or make one, but for occasional household use,
this will do. Are there any made-in-US cords any more? All I see in the
civilian stores any more is the China stuff.
Electricity seems so gentle until something like this happens. You had a
short (likely) or an arc on one side of the line (less likely); but both
make things hot enough to melt metal instantly.
Once while remodeling an old carriage house, one of the electrical guys
wiring outlets inside the building dropped his screwdriver across one side
of the line and the neutral in the CB box. I happened to be outside working
on the 3-wire feed lines. The current surge and resulting magnetic field
caused the lines to jump pulling them away from the building supports.
Fortunately, the inside guy was wearing safety glasses. There was molten
metal flying everywhere and the screwdriver disappeared. Scary.
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