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I tested my outlets the other day and found 148-152 volts at all my outlets. I then tested all my outlets with a commercial electric ms112h outlet tester and all tested good but still 150 volts. I then shut off all breakers except 1 outlet circuit still 150 volts. I then tried a different outlet circuit still 150 volts. What would my next step be?

I live in Oregon. I was using a Craftsman volt meter 82141 low end but seems like a good meter.

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    ALL your outlets? Or did you only test a few? Test them all. If you see any 90V, shut off your main right away and call the power company. This is a lost neutral affecting more than just your house. – Harper Jun 17 at 4:07
  • How old is your service at the meter? Do the wires have a cloth like jacket, and is falling apart? Can you see wires exposed and a green film? If so may be loosing the ground and 120 volt circuits could go 240 volt .Unplug tv and all electronic items. Turn off main breaker call power company. Any time they will come. – user101687 Jun 17 at 5:26
  • measure voltages at another house ... you may have a bad meter – jsotola Jun 17 at 6:03
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    When last did you replace the batteries in your multimeter? In some low-end meters, low batteries can cause inflated voltage readings (even before the low-bat warning appears on the display). – brhans Jun 17 at 12:26
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BRHANS Nailed it, I had a bad battery in my multimeter. Replaced the battery and I have 119 volts. Thats a fricking relief.

As far as balancing my panel I know nothing about it except I read that you should try and have equal amp breakers on either side to help keep it balanced.

You guys have been a great resource and I appreciate the advice!

  • That actually makes some sense. Low battery would mean normal voltage higher relative to the battery. – manassehkatz Jun 17 at 18:54
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    Glad it makes sense to somebody, I was totally lost. I was almost willing to bet money it was my panel. – Marc Jun 17 at 22:02
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    Occam's Razor Every battery-powered multimeter will eventually have a low battery and potentially problems along the way. It is very rare that anyone gets a lost neutral or other strange problem with their utility power. But because of the consequences, both need to be considered when you see 150V (or 90V). – manassehkatz Jun 17 at 22:23
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A typical "Magic 8-Ball" tester like the one you are using will activate with a broad range of voltages. The exact voltage will vary depending on the technology used, but I'd say it is a reasonable bet that anything between 70V and 250V (which would allow for some really messed up wiring without zapping the device or the user) will light up.

The multimeter is a more reliable device when it comes to specifics. It would be very unusual, though not impossible, for a modern multimeter to be 20% off - reading 125V as 150V. As it turns out, the problem was the multimeter battery, but keeping this answer as it could be relevant to others in the future. I would do the following:

  • Test against a different voltage source. Simplest would be mains voltage in a different building. If that is not an option, try a battery powered device, though AC and DC could be "off" by different amounts. You can also try the output of a device that takes a broad range of inputs and produces one stable output - e.g., a laptop charger will typically take 90V - 250V and output 18V or some other very specific value. Assuming the multimeter checks out OK on other stuff...
  • Determine whether you have "all high" or "half high, half low". The easiest way to do this is to check a "240V with neutral" receptacle - e.g., for a dryer or oven. You should measure nominally 240V hot-hot and 120V for both hot-neutral measurements. If you get 300V hot-hot and 150V for both hot-neutral measurements then you are "all high" (which I would find very unusual). If you have 240V hot-hot, 150V for one hot-neutral and 90V for the other hot-neutral then you likely have a lost neutral.

If the end result is either "all high" or "lost neutral", CONTACT YOUR ELECTRIC UTILITY IMMEDIATELY. Either one would be a very dangerous situation. "All high" will zap anything that is finely tuned for the standard 110V-120V or 220V-240V ranges. But potentially even worse is a lost neutral - it will zap 1/2 your devices by being too high, 1/2 by being too low ("brownout" type problems) and it can vary unpredictably as devices get turned on and off and pose a real human safety hazard.

  • So since I tested 2 different outlet circuits 1 at a time with all other circuits shut off at the breakers, can I assume its a problem at the panel or power company supply? – Marc Jun 17 at 5:16
  • Generally speaking, yes. But ideally you want to test circuits that are on "opposite sides" - which are typically alternating breakers. If you can turn on a 240V hot/hot/neutral (e.g., electric clothes dryer if you have one would be perfect) then you could clearly test hot/neutral vs. hot/neutral vs. hot/hot. But in the end, any significantly below 110V (below 220V for hot/hot) or above 125V (above 250V for hot/hot) with few or no breakers/devices on is likely to be a utility problem. – manassehkatz Jun 17 at 5:19
  • I believe the circuits were on opposite sides as I try to keep my panel balanced. I dont have an electric stove or dryer but I might rig a 240 outlet for testing. One other thought, just recently they installed a smart meter any chance this might be the culprit? – Marc Jun 17 at 5:51
  • A smart meter working properly should not have any effect on the voltage. It really should be monitoring voltage and current, draw a very small amount of power to power itself and may have a remote cutoff capability (for emergencies and/or delinquent payment) but should not itself be a transformer or otherwise modify the power. – manassehkatz Jun 17 at 5:55
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    That's exactly what I was warning you about @Marc. Two circuits is too small a sample, there's a 50/50 chance they are on the same leg. As far as your claim they are on opposite sides, everyone assumes they think they know how panels are phased, and 90% of them are wrong. How it actually is, is weird and counterintuitive... and unless you regularly phase panels, assume you are incorrect. – Harper Jun 17 at 14:43
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The likeliest explanation is a lost neutralaffecting several homes. This is a red alert! You should call your power company and report a power outage (seriously).

The interesting thing about yours is that it doesn't move much. Normally they move a LOT when you add and remove 120V loads. That suggests it is affecting several houses and they are averaging.

Why aren't your neighbors up in arms? Trust me - they don't know. When our entire complex was stricken, It took me days to notice, and only when my sweetie apologized for having to put the toast down several times. It took another day for me to get motivated to buy a voltmeter (my meters were elsewhere), at which point Pull mains, pound the alarm, power company is out in 30 minutes, done, happy toast. Meanwhile other tenants had major appliances fry, so lucky us. Anyway, you noticed, which makes you the hero.

But you checked all your circuits! Meaning two. Those have a 50/50 chance of being on the same pole, so giving the same reading. My whole apartment was on the same pole, just found that out that day.

But you checked circuits on opposite sides! Oh really. Pushmatic is the only panel with L1 on the left and L2 on the right. On all others, panel phasing is weird as heck, and you definitely do not understand it, unless you do. So revisit that assumption.

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