Pool motor switch zapped

[Kurt Ullman]

So, I open up the box following my wife telling me the motor isn't working and that there was a zap sound. I find a rather large black, sooty spot next to the on-off switch for the motor and the black wire burnt and the spade thing that the black wire was attached to still screwed into the switch, although as I mentioned the wire itself was no longer attached. Is this just a matter of switching out the switch or something worse that I should maybe call in repair people for?? I can do the latter, but that about exhausts what I am comfortable doing with electricity.

[RBM]

The connection was probably loose, overheated, and burned. Just replace the switch and any charred sections of conductor

[Terry]

With the power off, take the switch loose and wire nut the two wires together that were going to the switch. If the pump works then replace the switch. If it trips the breaker call an electrician.

[Kurt Ullman]

Thanks, I'll do that.

[Kurt Ullman]

Okay. This is a new pump, I'm not likely to mess with the guarantee or anything if I do this?

[Jeff Wisnia]

It may just be that whoever attached what you call "that spade thing" to the black wire didn't make a solid crimp and the joint developed high resistance over time, heated up, arced enough to melt the metal and failed.

Try shutting off the breaker feeding power to the switch and connect the black wire directly under the switch's terminal screw by bending a half loop on the wire.

Clean the wire and the switch terminal and screw so they are bright and shiny before attaching the wire to the switch, and tighten that screw firmly. (Check the other switch screw for tightness while you're at it.)

Turn the breaker back on and see how things go. Report back with results.

HTH,

Jeff

[RBM]

In the event that the pump is toast, Terry is just saving you time in replacing the switch on a bad pump

[Kurt Ullman]

Now that you mention it. I just remembered that the pool guy fixed the same problem a month or two ago. We replaced the pump this spring, then it went out again and we traded out the the new pump with another new one. Then he realized that the the black wire had come loose. He tightened it back up by taking off a little more insulation and crimping putting the connector (what I called the spade)and then it happened again. I am sorry not to tell you guys this earlier, but I forgot entirely about it until you mentioned. He kept the same switch and just rewired the black wire to the switch. The switch itself is probably about 6 years old. This change the calculus any? Could it be the new pump is pulling too many amps or something? Again, I am sorry, but I completely forgot about this.

Kurt

[RBM]

If it were pulling to much for the switch, the switch would fail. It does pull a pretty substantial amount of current, but the real problem is the cheesy spade terminals. If you have a choice, use ring terminals, and solder them

[Kurt Ullman]

Okay. Thanks

[Terry]

How far is the pump from the panel? The wire might be getting warm enough to cause problems. The lugs (spades) might be the weakest link.

[Kurt Ullman]

Panel as in the box that has the switch? 2-3 feet or so. Of course the space between the two is completely open. From the electrical panel in the breakerbox, clear on the other side of the house.

[Terry]

I was talking about the electrical panel. If it is over 100 ft then the electrician should have used a larger size wire or wired the pump for 240V.

The voltage drop could cause the pump to fail.

The smoke at the switch makes me suspect the lug or maybe the switch first, but if the pump does fail again it might be due to the wire size.

[Kurt Ullman]

I am also wondering if this was the real culprit and the pump may still have been good. We got about 9 years out of the pump we just replaced and the current one is just the third in 20 years, so I would doubt there are major problems with the wiring to the pump.

[Chris Lewis]

Couple of random thoughts:

1) Are you using a regular household electrical switch to control the pump? 2) Is this switch outdoors? How dampproofed is it? 3) is the crimp-on connector on solid or stranded wire?

Generally speaking, ordinary household switches shouldn't be used to switch motors (>= 1/4HP say) on and off routinely. As a power interrupt fine (mine has an ordinary switch for that purpose, but uses a timer with HP rating to control the pump cycle), but not for controlling routinely.

Motors, particularly pumps and compressors are hard starts, and pull a lot of amps momentarily. This erodes switch contacts, makes poor connections, and can cause the switch contacts and/or terminals to overheat.

If the switch shows any signs of burning, I'd recommend replacing it, even if it seems okay.

If replacing, go to a proper electrical supply and ask for a switch with a "HP rating" at least as big as the pump HP rating.

[I built a 1/2HP stationary belt sander. I'm using a toggle switch with a 1.5 HP motor rating for on/off switching.]

Failing that, ask for a "spec-grade" switch (eg: Hubbell). It'll cost considerably more than a cheap HD bulk pack switch, but should still be

[Kurt Ullman]

"Heavy duty" toggle switch

I think that may be the problem. As I was putting the new in, I noticed that the rubber "boot" on the outside had a hole in it. I am going to look around for another one. Maybe some silicon or similar on the switch?

Stranded.

I did

I got it at Ace, but if this was goes South, I'll try that the next time. I got this message after doing all the work. ALso, the switch I got is pretty the same one and the what I took out when the pool people replaced the switch about 5 years ago.

Already there. The g g askets look to be intact. No problems with the switch for the light directly below the ones with the prooblem, another reason I am leaning toward a leak at the "boot" as being the troublemaker.

This is stranded already.

Thanks for the help.

K

[Chris Lewis]

According to Kurt Ullman :

On the original and/or replacement, examine the switch very carefully.

It may have voltage/amperage and voltage/HP ratings listed on it. The "better" quality switches you should be using often have them stamped on the switch or a label.

I've "re-purposed" some industrial heavy duty relays/breakers/switches my dad tried to throw out out many years ago, and they all had HP ratings listed on them -

The radio control switch (good only to 600W incandescent ;-) powers my 1HP dust collector thru a relay that's rated for 15HP motors on 600V ;-)

Being a Canadian, I don't know Ace hardware, but if they cater to farmers & their requirements as I suspect, it may well be the proper switch. If from the automotive section, probably not ;-)

[Kurt Ullman]

It was 10 amp, 120 or 110 volts (can't remember right off). There was also a 20 amp side, but since the rating on the motor was less than that, I figured I was probably okay.

Ace is a smaller, neighborhood chain. As opposed to the big boxes like Home Depot and Lowes.

[Chris Lewis]

According to Kurt Ullman :

Sounds perhaps more like a generic utility ("hobby project") switch, not HP rated. If your pump is 1/2HP or larger, I suspect you're outside of its comfort zone :-(

If the switch has two poles, run them in parallel. May improve lifespan somewhat.

H'm. I thought it was going to be similar to our Home Hardware chain, which has quite a bit of light industrial/farm focus in semi-rural and rural areas. Their catalog contains, for example, chick incubators and can be ordered through any of their outlets (they have a _lot_), whether stocked or not.

That plus a feed & seed and Farm equipment dealer is just all a farmer here needs. (The more rural Home Hardware stores stock building materials too.)

Ace's web page makes it look like its doesn't seriously cover farm stuff. But that may just be the web pages.