Author Topic: Outlet measuring 137Vac. Something to get checked out?  (Read 3899 times)

forummm

  • Walrus Stache
  • *******
  • Posts: 7374
  • Senior Mustachian
Outlet measuring 137Vac. Something to get checked out?
« on: July 26, 2016, 11:59:09 AM »
We had a power outage (8 hours) following a thunderstorm. There was a loud bang nearby and we had a power surge (DW's computer shocked her). Some fans sound louder now (e.g. the microwave and refrigerator). And there's a buzz on a subwoofer. And our higher speed electric car charging station isn't working. I checked the voltage and noticed it was 137Vac for 120V outlets. I verified this at the breaker box. Is this something to be worried about? I called the power company and they said they'd have an engineer call me in a few days.

Sibley

  • Walrus Stache
  • *******
  • Posts: 7428
  • Location: Northwest Indiana
Re: Outlet measuring 137Vac. Something to get checked out?
« Reply #1 on: July 26, 2016, 12:18:44 PM »
Well, I'm not an electrician. But it sounds like the surge caused a lot of damage. Not being an electrician, I'd assume that there's something seriously wrong and cut power to the house before getting someone out to check everything ASAP.

However, I'm not an electrician, and I don't understand and I know it, so I'm going to be very conservative.

Spork

  • Walrus Stache
  • *******
  • Posts: 5742
    • Spork In The Eye
Re: Outlet measuring 137Vac. Something to get checked out?
« Reply #2 on: July 26, 2016, 12:22:24 PM »
IANAE... but that seems a little high to me.  I have graphs going back to 2012 and have never seen above about 126v (but it only measures once every 5 minutes... not continuously).  The "tough to burn out" incandescent bulbs are 130v.

And good luck.  We have a TON of little spikes and drop outs.  We've had the electric company out twice to put recording meters on.  Neither time would they even tell us the results of their tests.  But I sure have had a lot of circuit boards burn out.  I've learned to have all computer equipment on UPS and have a whole house surge as well as little surge plugs on pretty much every 120v appliance.

forummm

  • Walrus Stache
  • *******
  • Posts: 7374
  • Senior Mustachian
Re: Outlet measuring 137Vac. Something to get checked out?
« Reply #3 on: July 26, 2016, 01:06:35 PM »
The neighbor's outlet was 135V. Definitely not just my house. I assumed it was the same as mine because the wires from the street are shared.

zolotiyeruki

  • Walrus Stache
  • *******
  • Posts: 5603
  • Location: State: Denial
Re: Outlet measuring 137Vac. Something to get checked out?
« Reply #4 on: July 26, 2016, 01:40:32 PM »
IANAE... but that seems a little high to me.  I have graphs going back to 2012 and have never seen above about 126v (but it only measures once every 5 minutes... not continuously).  The "tough to burn out" incandescent bulbs are 130v.

And good luck.  We have a TON of little spikes and drop outs.  We've had the electric company out twice to put recording meters on.  Neither time would they even tell us the results of their tests.  But I sure have had a lot of circuit boards burn out.  I've learned to have all computer equipment on UPS and have a whole house surge as well as little surge plugs on pretty much every 120v appliance.
Unless you're paying a bunch of extra money on an "online" UPS, the UPS doesn't do any power conditioning besides surge protection and providing power when the mains goes out.

Spork

  • Walrus Stache
  • *******
  • Posts: 5742
    • Spork In The Eye
Re: Outlet measuring 137Vac. Something to get checked out?
« Reply #5 on: July 26, 2016, 01:58:23 PM »
IANAE... but that seems a little high to me.  I have graphs going back to 2012 and have never seen above about 126v (but it only measures once every 5 minutes... not continuously).  The "tough to burn out" incandescent bulbs are 130v.

And good luck.  We have a TON of little spikes and drop outs.  We've had the electric company out twice to put recording meters on.  Neither time would they even tell us the results of their tests.  But I sure have had a lot of circuit boards burn out.  I've learned to have all computer equipment on UPS and have a whole house surge as well as little surge plugs on pretty much every 120v appliance.
Unless you're paying a bunch of extra money on an "online" UPS, the UPS doesn't do any power conditioning besides surge protection and providing power when the mains goes out.

I seem to have an almost infinite supply of nice rack mount APC UPS's that I have acquired for free over the years.

BudgetSlasher

  • Handlebar Stache
  • *****
  • Posts: 1212
Re: Outlet measuring 137Vac. Something to get checked out?
« Reply #6 on: July 26, 2016, 02:52:31 PM »
The neighbor's outlet was 135V. Definitely not just my house. I assumed it was the same as mine because the wires from the street are shared.

Good assumption and good catch. If you haven't I'd call and inform/tell/complain to the power company.

Most modern electronics are built to be around the world (115-250v) so the voltage for you computer (at least laptop)/cellphone/pretty much everything else that converts should be alright you can check the label. Can you tester also give you hertz, having the hertz would be a bigger concern to me.

As Spork pointed out items meant to be be on 120v might have issues.

Spork

  • Walrus Stache
  • *******
  • Posts: 5742
    • Spork In The Eye
Re: Outlet measuring 137Vac. Something to get checked out?
« Reply #7 on: July 26, 2016, 03:09:58 PM »
The neighbor's outlet was 135V. Definitely not just my house. I assumed it was the same as mine because the wires from the street are shared.

Good assumption and good catch. If you haven't I'd call and inform/tell/complain to the power company.

Most modern electronics are built to be around the world (115-250v) so the voltage for you computer (at least laptop)/cellphone/pretty much everything else that converts should be alright you can check the label. Can you tester also give you hertz, having the hertz would be a bigger concern to me.

As Spork pointed out items meant to be be on 120v might have issues.

BTW... The only thing I have that will display Hz is a Kill-a-watt.  If you've got one of those, plug that sucker in.

forummm

  • Walrus Stache
  • *******
  • Posts: 7374
  • Senior Mustachian
Re: Outlet measuring 137Vac. Something to get checked out?
« Reply #8 on: July 26, 2016, 04:59:04 PM »
I seem to have an almost infinite supply of nice rack mount APC UPS's that I have acquired for free over the years.

<nods> Hey, nice rack...mount.

forummm

  • Walrus Stache
  • *******
  • Posts: 7374
  • Senior Mustachian
Re: Outlet measuring 137Vac. Something to get checked out?
« Reply #9 on: July 26, 2016, 05:19:15 PM »
Power company came out. Said I was right that it was way high. The power went out for about an hour while he fixed it. Now it's registering 119Vac and my electric vehicle charging station is working again! And the refrigerator is quieter now.

wienerdog

  • Pencil Stache
  • ****
  • Posts: 587
Re: Outlet measuring 137Vac. Something to get checked out?
« Reply #10 on: July 26, 2016, 06:37:20 PM »
Sounds like a transformer blew and it probably switched in power from a different route.  They either adjusted the tap on the transformer that was feeding your area now or fixed the original transformer and put the route back to how it was.

paddedhat

  • Handlebar Stache
  • *****
  • Posts: 2228
Re: Outlet measuring 137Vac. Something to get checked out?
« Reply #11 on: July 26, 2016, 08:40:36 PM »
This can also be the result of a damaged neutral at the transformer, or the incoming line. It can result in a weird series/parallel delivery problem, where the neutral is creating a bridge between both of the 120V legs. I actually had a customer who had reading as high as 156V to ground in his home, after the neutral on an underground service feed had developed a lot of resistance. The power company lied their butts off, and denied responsibility, until I met with their engineer, and showed him some of the readings.

zolotiyeruki

  • Walrus Stache
  • *******
  • Posts: 5603
  • Location: State: Denial
Re: Outlet measuring 137Vac. Something to get checked out?
« Reply #12 on: July 27, 2016, 07:20:12 AM »
IANAE... but that seems a little high to me.  I have graphs going back to 2012 and have never seen above about 126v (but it only measures once every 5 minutes... not continuously).  The "tough to burn out" incandescent bulbs are 130v.

And good luck.  We have a TON of little spikes and drop outs.  We've had the electric company out twice to put recording meters on.  Neither time would they even tell us the results of their tests.  But I sure have had a lot of circuit boards burn out.  I've learned to have all computer equipment on UPS and have a whole house surge as well as little surge plugs on pretty much every 120v appliance.
Unless you're paying a bunch of extra money on an "online" UPS, the UPS doesn't do any power conditioning besides surge protection and providing power when the mains goes out.

I seem to have an almost infinite supply of nice rack mount APC UPS's that I have acquired for free over the years.
That doesn't necessarily mean they're online UPSes, though.  I've had a few APC units myself, and they're all offline UPSes.

Rollin

  • Handlebar Stache
  • *****
  • Posts: 1230
  • Location: West-Central Florida - USA
Re: Outlet measuring 137Vac. Something to get checked out?
« Reply #13 on: July 27, 2016, 08:46:17 AM »
The neighbor's outlet was 135V. Definitely not just my house. I assumed it was the same as mine because the wires from the street are shared.

Good assumption and good catch. If you haven't I'd call and inform/tell/complain to the power company.

Most modern electronics are built to be around the world (115-250v) so the voltage for you computer (at least laptop)/cellphone/pretty much everything else that converts should be alright you can check the label. Can you tester also give you hertz, having the hertz would be a bigger concern to me.

As Spork pointed out items meant to be be on 120v might have issues.

BTW... The only thing I have that will display Hz is a Kill-a-watt.  If you've got one of those, plug that sucker in.

My local library offers these for loan - maybe yours?

Spork

  • Walrus Stache
  • *******
  • Posts: 5742
    • Spork In The Eye
Re: Outlet measuring 137Vac. Something to get checked out?
« Reply #14 on: July 27, 2016, 08:56:54 AM »
IANAE... but that seems a little high to me.  I have graphs going back to 2012 and have never seen above about 126v (but it only measures once every 5 minutes... not continuously).  The "tough to burn out" incandescent bulbs are 130v.

And good luck.  We have a TON of little spikes and drop outs.  We've had the electric company out twice to put recording meters on.  Neither time would they even tell us the results of their tests.  But I sure have had a lot of circuit boards burn out.  I've learned to have all computer equipment on UPS and have a whole house surge as well as little surge plugs on pretty much every 120v appliance.
Unless you're paying a bunch of extra money on an "online" UPS, the UPS doesn't do any power conditioning besides surge protection and providing power when the mains goes out.

I seem to have an almost infinite supply of nice rack mount APC UPS's that I have acquired for free over the years.
That doesn't necessarily mean they're online UPSes, though.  I've had a few APC units myself, and they're all offline UPSes.

No... it's line interactive.  APC line interactive UPS's DO have power conditioning.  In fact, where your power fluctuates a lot, they will kick in quite a lot, running for a few seconds on the batteries here and there throughout the day.  My power sucks.  I get several short transfers a day.  (3 yesterday, for example)