I've got kind of a puzzling problem.
I was called to a residence of a complaint of power dips. Customer stated that they usually came in batches of 5 to 6 dips at a time and seemingly at random times of the day.
I was lucky enough to experience it first hand. Fans plugged into outlets would very noticeably slow down and then recover.
This was independent of any major loads kicking on. My first thought was that a bad connection existed somewhere. The customer didn't want me to turn the power off that day so I'm going back later. I did notice that the problem seemed to be isolated to one leg of the single phase service.
Here's the puzzling part:
I flipped my meter over to hertz just out of curiosity. It was rock steady at 60 hz except during those dips where it would drop to the 57-59 hz range but then would bounce up to 120 - 155 hz. Some of the digital clocks on that leg had been speeding up since the problem started.
The more I've thought about this I just can't imagine any situation other than a utility problem that could cause that frequency fluctuation. However, I've never really monitored frequency during a voltage dip before.
Does anyone have any thoughts?
I was called to a residence of a complaint of power dips. Customer stated that they usually came in batches of 5 to 6 dips at a time and seemingly at random times of the day.
I was lucky enough to experience it first hand. Fans plugged into outlets would very noticeably slow down and then recover.
This was independent of any major loads kicking on. My first thought was that a bad connection existed somewhere. The customer didn't want me to turn the power off that day so I'm going back later. I did notice that the problem seemed to be isolated to one leg of the single phase service.
Here's the puzzling part:
I flipped my meter over to hertz just out of curiosity. It was rock steady at 60 hz except during those dips where it would drop to the 57-59 hz range but then would bounce up to 120 - 155 hz. Some of the digital clocks on that leg had been speeding up since the problem started.
The more I've thought about this I just can't imagine any situation other than a utility problem that could cause that frequency fluctuation. However, I've never really monitored frequency during a voltage dip before.
Does anyone have any thoughts?