Do you monitor your shop voltage?

[Matt Mattingley]

I’ve been monitoring my shop the voltage for about three years. I’ve seen highs of 247 V and lows of 232 V. I keep Visual display on the wall. Right now I am running at 242.

I do run a RPC... so my other voltages could be out of whack a bit with the generated legs.

I’m not so concerned about high-voltage from the PC, but low-voltage can this be a problem for three phase equipment?

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[Art Mann]

I had a voltage problem in my old shop that caused me to monitor the voltage closely for a while. The root cause turned out to be a squirrel gnawing an exposed aluminum neutral wire from the utility pole. Depending on the load balance, one leg voltage would drop low with respect to neutral and the other one would go high. I finally figured it out and had the utility company come fix the problem. I was surprised to hear them say this problem with squirrels happens all the time.

In my old neighborhood, the transmission lines weren't quite adequate and the voltage would droop to around 110 on hot summer days with a high current load. That wasn't a real problem because electrical devices are still designed to work at that voltage even though the nominal voltage nationwide is 120/240. I monitored shop voltage for that reason as well on hot summer days.

As far as low voltage goes, check the placard on your motors. Quite often, 3 phase motors are rated for 208 volts.

[Jim Becker]

I don't monitor it, but a few years ago I was having an issue with my slider suddenly shutting down with frequency and it wasn't an internal breaker. At the suggestion of Sam Blasco, I began checking line voltage and found it was just outside of the acceptable range for the machine. It was likely an issue at the local transformer serving our property. A buck/boost transformer put on the saw fixed that. I've had no issues otherwise with voltage however. There's certainly no harm in monitoring things!

(to be clear, my power is strictly single phase)

[Darcy Warner]

Not really. Only time I know is when I am trouble shooting something. Pole power in is usually around 492v.

My low voltage from my 175kva transformer is usually around 242v and my single phase hangs out around 127v from my 480 to 120 transformer.

[Bill Dufour]

A smart meter installed by your utility should show voltage as one of the rotating extra readouts. Unfortunately my utility has disabled all the extra information so mine is a dumb meter. There is no indication of current, voltage etc just a odometer type readout of total watt hours used which does not move fast enough to see any movement.
I wonder if I can ask them to replace a defective meter since it is not a smart meter like thy said it would be? I think they disabled these features so people would not call them and ask what do the extra numbers mean. Like my Ford with idiot light switch to run the oil pressure gauge so folks do not complain that oil pressure varies with rpm and engine temperature.
Bill D.

[Rod Sheridan]

Nope, I measured it once, we're normally a couple percent high...........Rod.

[Mike Heidrick]

I put all my control voltages on 3phase equipment on the non generated legs of the rpc. I am balanced as well but controls like somewhat constants from the pc better. I just use meter. Nothing permanent needed for me. Many 3ph motors can handle 208v-240v so just check your motor but the controls if any might need more exacting voltages (timers, relays etc).