I need a little info.
This is my problem :
Have nemerous sewage pump stations (10Hp & 15Hp duplex Units w/ motors wound to 230V) at the end of two long utility company 2 phase runs. Power company has installed center tap grounded open delta transformers to provide 3 phase, 240V, 60Hz service at each location soley for the operation of these stations. What I am getting is unbalanced phases - what I was typically seeing is 228V, 242V, 238V (or something close - workable), three days ago voltages were @ 245V, 244V, 263V.. after a conversation they tweeked something somewhere and it looks like 246V, 228V, 268V since yesterday. The motors do not have Hp to de-rate past 90%, and the phase unbalance is tripping the thermal overloads - as I do not have the choice to not run them. My recent conversations with the utility provider says that at this location, they try to keep the voltage within 5% avg, 10% max, but unbalanced may be 4% - yeah right..
Provided my motors don't burn out by the time a response comes - What information can I pick from your brains as far as the next logical step?
??Somebody said something about using some sort of line regulator, or voltage conditioner? Is one available for the service voltage present, and at what cost? Any info / help would be appreciated.
This is my problem :
Have nemerous sewage pump stations (10Hp & 15Hp duplex Units w/ motors wound to 230V) at the end of two long utility company 2 phase runs. Power company has installed center tap grounded open delta transformers to provide 3 phase, 240V, 60Hz service at each location soley for the operation of these stations. What I am getting is unbalanced phases - what I was typically seeing is 228V, 242V, 238V (or something close - workable), three days ago voltages were @ 245V, 244V, 263V.. after a conversation they tweeked something somewhere and it looks like 246V, 228V, 268V since yesterday. The motors do not have Hp to de-rate past 90%, and the phase unbalance is tripping the thermal overloads - as I do not have the choice to not run them. My recent conversations with the utility provider says that at this location, they try to keep the voltage within 5% avg, 10% max, but unbalanced may be 4% - yeah right..
Provided my motors don't burn out by the time a response comes - What information can I pick from your brains as far as the next logical step?
??Somebody said something about using some sort of line regulator, or voltage conditioner? Is one available for the service voltage present, and at what cost? Any info / help would be appreciated.