OT: Electrical Fire

[Puckdropper]

I went to turn the pool pump on today and noticed the outlet the timer plugged in to was charred and black. I'm not 100% sure of the cause, but the important thing is the electrical box contained the fire and prevented it from spreading.

I'm not sure of the exact cause (I suspect it was a combination of things), but the outlet shows the most char (the fire happened in the box) while the pump power cord was melted to the timer.

I suppose I'll have to have an electrician come out on Monday. Anything I should ask them before accepting them?

Puckdropper

[Martin H. Eastburn]

My suspect is a loose wire (due to heat of the day or vibration) and arcing did the rest.

Mart> I went to turn the pool pump on today and noticed the outlet the timer

[Ed Pawlowski]

Any lightning in the area? Not a direct hit, mind you, but a jolt to the ground that found its way to the pool circuit.

I had a similar situation a couple of weeks ago. I'm not sure where the hit was, but an X-1- module in the garage was burned, as was the receptacle it was plugged into. Repaired that and found that the outside light fixture it control was out. One bulb had the base welded into the socket so I replaced the fixture. Doing so, If found a 3/16" hole in the downspout where there was an arc from the lamp holder that was nearly touching it. Travelled back to the main panel where it took out a breaker, AV receiver, and TV on that circuit.

[Puckdropper]

"Martin H. Eastburn" wrote in news:7fSXn.268835$ [e-mail]:

I took the timer apart, and think I've found a contributer. The timer outlet connected via 6" long wires with 16 gauge wire. The hot wire shows a significant amount of melting (plastic completely removed) while the nuetral and ground wires are fine.

Once I get some daylight, I'll take the outlet apart and look around there.

Puckdropper

[Lew Hodgett]

------------------------ Classic description of an arcing ground fault.

The fault current was less than the rating of the protective device which allowed it to continue until it reached open circuit which was probably a conductor that melted thru.

Consider yourself lucky.

During my career, had a customer who lost a 1,200 amp, 480V switchboard the same way when a rat touched a hot bus bar and case ground at the same time, on a cold winter's evening.

The plant was down almost a month while a replacement switchboard was built, then installed and fire repairs were made.

Lew

[Puckdropper]

"Lew Hodgett" wrote in news:4c301bf0$0$32442 $ [e-mail]:

That does make sense. I could see a partial short arcing and snapping for quite some time until something burns.

Isn't the GFCI supposed to detect and trip when this occurs? The outlet was an older GFCI (at least 3 years old, it was here when we moved in) and might have failed on. OTOH, if the arcing was occuring before the outlet it would have done no good to trip.

I do, but want to point out that the outlet box was responsible for stopping the spread of fire.

We've got space to mount the electrical box on its own post 6-18" away from the deck, so if something happens again a fire would have to travel that far to catch the deck.

*snip*

Puckdropper

[Michael Kenefick]

[Ed Pawlowski]

"Lew Hodgett" wrote

Was the rat OK? PETA wants to know about the poor fellow.

[Larry Jaques]

On 04 Jul 2010 01:44:57 GMT, Puckdropper wrote the following:

You might ask for references, hourly prices, quote for the job, and what they feel is the cause of the failure. It could have been something as simple as a loose connection at the outlet which built up enough resistance that heat built up and caused the meltdown. Was it the proper metal-canned high-wattage timer or a cheap plastic plugin, Pucky? What size pool/pump?

-- It's also helpful to realize that this very body that we have, that's sitting right here right now, with its aches and its pleasures, is exactly what we need to be fully human, fully awake, fully alive. -- Pema Chodron

[Larry Jaques]

On Sun, 4 Jul 2010 08:28:50 -0400, "Ed Pawlowski" wrote the following:

Riddle me this:

How do you lose a 1,200A/480V switchboard and NOT lose the rat, Ed? Hell, it was so crispified, Colonel Sanders couldn't even use it over at Kentucky Fried Rat.

-- It's also helpful to realize that this very body that we have, that's sitting right here right now, with its aches and its pleasures, is exactly what we need to be fully human, fully awake, fully alive. -- Pema Chodron

[Lew Hodgett]

------------------------------ You have answered your own question.

One of the advantages of having a GFCI c'bkr as opposed to a GFCI receptacle.

Lew

Lew

[krw]

A GFCI only trips on a fault to ground. This may have been a high resistance or intermittent connection, like a loose screw, which an AFCI would catch but a GFCI would not.

That's why they're required. ;-)

If it makes you feel better. An electrical fire isn't likely to get out of a weatherproof box before the breaker trips.

[Leon]

Not always the case , I have a GFCI in my bathroom, it covers my 2 boathrooms, out door outlets, kitchen, and garage outlets. It is not unusual for that thing to trip under a load form a power tool.

[krw]

Your tool has a leak to ground.

[J. Clarke]

If you want to be precise, a GFCI trips on an imbalance in currents between hot and neutral If it's tripping under a load from a power tool you really should find the leakage path and fix it.

[Josepi]

Your wiring has a leak to ground.

When you shut off the power tool they generate high voltage spikes on your wiring and the high voltage spike finds the nick in the insulation and the GFCI sees it and does it's thing. This soculd be in the tool also.

WTF are you doing sharing a GFCI in your bathroom with the garage and kitchen?...LOL

Nobody ever use a hairdryer while your engine block heater cuts in or a kettle gets plugged in?

[Puckdropper]

Larry Jaques wrote in news: [e-mail]:

The timer was a $15-20 outdoor timer rated at 15A for all types of loads. The pump is a 1.5 horse motor, with 15A on the motor information sticker.

I've looked in to better timers, and there's one for somewhere around $70 that can handle up to 24A. That's more than the circuit breaker.

Puckdropper

[Puckdropper]

"Ed Pawlowski" wrote in news:2pydnYwJNNpIZbLRnZ2dnUVZ [e-mail]:

*snip*

No lightning anywhere around for the last several days. Not even a drop of rain (pardon my use of that 4-letter word).

Puckdropper

[Lew Hodgett]

----------------------------- IOW, you're basic POS resi device.

You need a timer with a 2HP@120V rated set of contacts.

Lew

[Puckdropper]

"Lew Hodgett" wrote in news:4c317362$0$4745 $ [e-mail]:

Yeah, basically. It said something on the back about 15A motor load rating, but the outlet in the timer was 16 gauge wire.

I'm looking at replacing it with this timer:

have to replace the cord on the pump motor anyway, so it's no big deal to cut the plug off and wire it in to the timer box.

Puckdropper