Is 135v to 139v AC voltage too high?

[balloonshark]

My 2 UPS's started going off tonight. One has a display and it shows anywhere from 135v to 139v the last couple of hours. My multimeter gives the same readings. I called the power company to report it and a truck rolled and left. Is that voltage too high? Should I be worried about everything connected to an outlet right now?

 

[Blain]

My 2 UPS's started going off tonight. One has a display and it shows anywhere from 135v to 139v the last couple of hours. My multimeter gives the same readings. I called the power company to report it and a truck rolled and left. Is that voltage too high? Should I be worried about everything connected to an outlet right now?

Greater than ±5%... Yes it is too high.
Maybe the truck is going to pick up a new transformer.
Call them to check the status of your report.

 

[balloonshark]

The power just went out for a few seconds 19 minutes ago. When it came back on the voltage shows at 123v which is within range. I couldn't report back until now because the internet went off at the same time and just came back on. I'm glad that I called in and reported it. The issue must have been located elsewhere. I hope nothing got damaged when the voltage was high.

 

[who?]

I wonder if the moving center contact in a transformer is accessible on the outside of the transformer such that an animal could get stuck in the mechanism. They may have had to remove some remains so that it could move freely again.

 

[marvdmartian]

Your equipment connected to the UPS was in no danger, as the UPS has built in circuitry to bring that voltage down (or bring an undervoltage up). If you're worried about your other electronics, or major appliances, buy an inexpensive line conditioner to plug into the wall, then plug the equipment/appliance(s) into, as it will do the same thing your UPS does (only without the battery backup).

Most US electronics and appliances are rated to handle up to 150 VAC, without any difficulty, at 60 Hz. A more serious condition would be a brown out, or if one leg of the 3-phase transformer went down, which can mess up electronics, and usually isn't protected against (unless your UPS just cuts power input, and goes on battery backup).

 

[stormkroe]

The neutral on pole mounted transformers, especially old ones, will sometimes corrode and sometimes completely open. When they completely open you can get a full phase to phase path across anything plugged in. It's a super quick temporary fix for the linemen because all they have to do is 'crack' the post loose, then torque it back down to make the connection good enough to hold over until a new transformer can be installed.
The next time that happens, check with your meter from hot to ground instead of hot to neutral. If voltage to ground is ~120 then it's a compromised neutral almost certainly.

 

[balloonshark]

Thanks for the information everyone. When the voltage was high I did check from positive to ground at an outlet and the voltage was the same. I'm assuming you meant multimeter and not the outside power meter.

Hopefully it was an easy fix for the guys considering it was a weekend and it decided to snow yesterday.