electrical

[coach]

ok guys, desparately need help with electrical in shop.
moved to new shop in June 2021. since then have burned out 2 fein vacs, 1 dust collector and 2 compressrs.
the compresor motor was smoking adthe on off switch wouldn't function. replaced the compressor friday and exact same thing happened today.

the switch burned up (literally) on the dust collector and the fein vacs.

this had happened over the last 6 months. I figured the feins just wore ot but the extractor was less than 2 years old. the comprssor was 5 yrs old but hen the new one was a weekend old.
electrician came out and could find nothing.
The electric company (FPL) just left and found nothing.

I came to the forum because I know a lot of you guys are smarter than the people I had here.
Any input or ideas what to look for would be greatly appreciated.
The shop is at a standstill. I cannot afford to burn up my shop bot or any other tools.
figures happens when we getting busy.

Thanks for any input.
Dave
www.cabinetsallwood.net

[dana_swift]

David- from your description it sounds like the voltage is far lower than the motors are expecting.

Check the voltage at the motors when they are running. I suspect that 120 volt motors are only getting 100 or so. 240 volt motors perhaps 200. That causes an increase in current and burns up the motors and switches like you described.

Compressors draw LOTS of current. When the motors are not running everything will appear normal.

Let us know what you learn with the voltmeter..

D

[planman]

What you are describing sounds like a textbook low voltage situation.

Two options:

a) You need to put a multimeter on the hot leads before and after you turn the machine on. Check the voltage. Call the power company (They will come out fast because it is a fire danger situation).

b) Just call the power company and tell them what is happening . (No mulitimeter required). (They will come out fast because it is a fire danger situation).

If you aren't familiar with a multimeter... I would opt for B and I bet you see them same day or tomorrow.

[jerry_stanek]

Is the feed 3 phase or 1 phase? It sounds like 3 phase if it is check into a buck booster.

[Ajcoholic]

In my last shop, I had an over-voltage issue. There was a mines-assaying shop right across the road (which used a huge amount of power, we both were fed from three phase 600V nominal). The transformer feeding our shop was set up for about 640V. Then the assaying place moved. All of a sudden, motors started to burn out. And three phase, multi speed/multi wind motors cost a fortune to get rewound.

AFter our shaper, power feed on the wide belt and the radial arm saw motor burned out, the rewind place said to check the voltage. 641V... I had the electrical company turn down the transformer to 605V, and for several years after, never had an issue and motors which ran hot, didnt anymore.

SO, too high a voltage can be just as much a problem, as too low.

AJC

[dana_swift]

Andrew- it is indeed just as bad a problem. Just not near as common.

David- one other thing occurred to me since I wrote my original response. You may have a bad (resistive) joint somewhere in the power feed. Not likely as the lights would be flickering a lot.

The other thing of course is you have had a run of bad luck. The voltmeter will figure out which case you have.

Good luck-

D

[dkrage]

David
Which, if any were 220v single phase?
Do you have three phase?

There is a problem called "single phasing" whereby one leg of the circuit goes soft/low/to zero and wreaks havoc on motors...causing excessive instantaneous current draw on one leg and killing them. The challenge is catching it as often it is somewhat intermittent.
In order to catch it the power company would need to set a line monitor in place.

This can be caused by any recently added large single ph loads in the area, and, when turned on, can cause an imbalance. It can also be caused by a transformer that is beginning to fail.

Regardless, hound your power company. As others have stated, this is a potentially disastrous situation on many levels if not remedied.

Good luck!