Scheduled Electrical Power "Reset" Everyday?

[bicker]

I wonder if there is anyone other there who works for an electrical utility? Every morning at either 6:00 AM or 6:15 AM (90% of the time it is 6:15 AM, and I've seen this happen at no other times, not even off by a minute or two from either of those times) my UPS detects a power incident of some sort. Is there something that is scheduled to "happen" on the power lines every day at the same time each morning?

 

[Duckfan-in-Chicago]

Don't work for the utilities, but I'm in the industry.

There could be something on the same line as your UPS that is being turned on at that exact time. I work in a building where there are some chllers and generators that are actual jet turbines. When any of those things come online, there is a momentary dimming of the lights because of the initial inrush current.

I could easily see a factory tied to the grid on the same line with some big equipment that starts at 6 or 6:15 every day causing what's described.

If it's just an event the UPS is recording, but it's not transfering power, that's really not an issue-just sensitive equipment. If the UPS is taking over the power supply every morning, that's unacceptable and the power company should find the issue and isolate it.

 

[GeorgeG]

I worked for an electric utility for 37 years. The companies do not schedule interruptions like you described.

What you are seeing is what we call a "trip and reclose" of a primary distribution circuit. That is when a brief fault trips the circuit breaker in the substation and a device called a recloser automatically resets it. From my experience, it could be one of two similar things. Duckfan-in-Chicago is correct about a large factory being one possible source. Some factories or plants will start a large piece of equipment about the same time every morning and that surge can trip the circuit breaker at the substation or blow a line fuse feeding the equipment, which can also trip the circuit breaker. That is not supposed to happen and your electric company can track that down. It's likely they are already working on doing just that.

The other cause might be squirrels or other animals getting on the lines. It's common for this activity to occur around the time you describe and this can happen with some regularity. However, since your problem occurs at exactly the same time every day, I suspect a factory might be the culprit.

Either way, the electric company would keep records of all such activity and a call to them would be in order. Have a list of the dates and times ready so they can match the activity to what they have on record. It could even be a combination of different activity. If it is a factory or other large power user causing the problem, they will work with them to correct it.

 

[bicker]

Interesting. We live right on the Interstate, so I was thinking that perhaps the lights going off could cause this, but I guess if the lights going off could cause it then surely the lights going on would as well, and that's simply not the case. There is a factory about 3/4 mile down the block. They have several huge liquid nitrogen towers outside, so clearly they've got some heavy machinery inside. (It's actually pretty funny-looking; they had a leak, apparently, about six months back and the towers froze over like massive popcicles, and they still haven't defrosted...) However, the factory is (just) over the town line; Perhaps the electrical utility doesn't care about town lines, though.

 

[GeorgeG]

Interesting. We live right on the Interstate, so I was thinking that perhaps the lights going off could cause this, but I guess if the lights going off could cause it then surely the lights going on would as well, and that's simply not the case. There is a factory about 3/4 mile down the block. They have several huge liquid nitrogen towers outside, so clearly they've got some heavy machinery inside. (It's actually pretty funny-looking; they had a leak, apparently, about six months back and the towers froze over like massive popcicles, and they still haven't defrosted...) However, the factory is (just) over the town line; Perhaps the electrical utility doesn't care about town lines, though.

Town lines don't have much to do with electric companies except those that are stictly municiple. Even then, they usually buy their electricity from a larger company and may feed off a shared circuit. My company served three states and primary distribution circuits crossed state lines. At each crossing we had what we called "state line meters" to keep track of usage for interstate trade and tax purposes.

The best thing is to contact your electric utility company. A factory 3/4 of a mile away could very easily be causing your problem. The electric company can, and should, track down the cause (or causes) and resolve the issue. There could be some faulty equipment in the factory, new equipment that is bigger than what current fusing is set for, or even some electric company fuse coordination or device settings that need to be changed. I used to routinely assign engineers to investigate such things.