kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
222 is within 10% of 240. But is still too much imbalance, particularly for three phase motor that is at/near rated loading. I think most motor manufacturers recommend 1-2% max voltage imbalance, particularly at full load rating. Derating the motor is recommended if imbalance is expected to be more than 3% for any significant time period.If my memory serves me right there are 2 transformers on the pole. There is 1 may be 2 other business besides us tapped to the larger of the two transformers and the other small one going to us.
I emailed our POCO rep., and he said that the voltages I gave him were within their voltage +/- 10%. Asked if we were seeing equipment issues. I replied with the forementioned VFD and speaking to the refrigeration guy the phase monitor is tripping our glycol system as well. Waiting on his reply.
Google suggests many utility companies consider up to 3% imbalance as being acceptable. Your no load voltage likely is rather balanced though. Still have a feeling the high leg transformer is overloaded or is at certain load conditions anyway. There likely is more load now than when the bank was first put into service.