Power Conditioning Equipment
Power Conditioning Equipment
(OP)
For the Utility Guys Here:
I have an issue where a fairly large (480 volt, 1200 kW) customer feels they have voltage regulation issues. PF averages 75 to 80%. The customer is served from 2 miles of 336 Al. OH line at 25 kV and a 2500 kVA padmount tx. We have recorded the voltage on 2 separate occasions at 1 minute intervals and found the service voltage to vary +/- 4 to 5 percent which we believe is pretty good and the levels are well balanced.
Probably a 3000 amp plus service.
Facility is located in the Southeastern US.
The problem appears that the customer has purchased some equipment that has a +/- 2% tolerance, to which we have told them that we could not gaurantee that level of swing on the system and they would need to install additional equipment to maintain their required level of voltage. The customer is asking for +/- 1% swing!
Aside from ideas anyone might have, I am also interested in others that have seen this issue and any equipment/mfg that might have been used to solve the problem.
Thanks in advance!
Alan
I have an issue where a fairly large (480 volt, 1200 kW) customer feels they have voltage regulation issues. PF averages 75 to 80%. The customer is served from 2 miles of 336 Al. OH line at 25 kV and a 2500 kVA padmount tx. We have recorded the voltage on 2 separate occasions at 1 minute intervals and found the service voltage to vary +/- 4 to 5 percent which we believe is pretty good and the levels are well balanced.
Probably a 3000 amp plus service.
Facility is located in the Southeastern US.
The problem appears that the customer has purchased some equipment that has a +/- 2% tolerance, to which we have told them that we could not gaurantee that level of swing on the system and they would need to install additional equipment to maintain their required level of voltage. The customer is asking for +/- 1% swing!
Aside from ideas anyone might have, I am also interested in others that have seen this issue and any equipment/mfg that might have been used to solve the problem.
Thanks in advance!
Alan
Alan






RE: Power Conditioning Equipment
RE: Power Conditioning Equipment
But davidbeach is correct that utilities are not required to provide that level of service. However, many utilities do offer expanded service, like this, for an additionl price.
RE: Power Conditioning Equipment
The problem is a bit sensitive as you might understand. The customer is unhappy, wants to expand, but says they can't as long as the voltage problem exists. As always they play the loss of jobs card.
Alan
RE: Power Conditioning Equipment
Here it's a mixed bag, with complaints also making it into the papers, and irritating rate payers about shifting costs.
Small towns, and local coops are worse about things like bending over for larger businesses.
RE: Power Conditioning Equipment
Alan
RE: Power Conditioning Equipment
If the customer installs conditioning equipment for just the problem machine, it may be of much less capacity, and much more economical.
If the customer wants premium quality power he may have to pay a premium price.
I would consider a two pronged approach;
1st, find a good negotiator to work with the customer.
2nd, apply to your regulatory agency for an amended tariff to recover the cost of supplying power at higher quality levels than presently specified, should a customer request request such service.
On the public relations front, rather than saying it yourselves, it may be better if a third party "discovers" that his business wants to unload his extra costs onto the community as a whole.
You may consider starting the process of seeking regulatory approval to raise the rates of all your other customers to pay for this installation. The PR may cause the customer to back off and if and when the regulatory body prohibits higher rates to pay for the installation, you can offer to install whatever the customer desires.
Question;
Do you install industrial services free or does the customer pay as in many jurisdictions? If the customer pays the original installation, you should be able to charge him for upgrades.
Once the customer realizes that he will have to pay, he will probably opt for the much less expensive course of installing his own conditioning equipment.
Bill
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"Why not the best?"
Jimmy Carter
RE: Power Conditioning Equipment
We have about 4 options here:
Do nothing....probably NOT!
Customer installs, owns, and maintains equipment.
Utility installs, owns, and maintains equipment for a fee.
Utility installs, owns, and maintains equipment for free...not the recommended course of action.
We are already discussing the options with the customer, and of course they want it for free, but I am recommending that not happen.
Mainly looking for mfg's/equipment some of you may have experience with.
Thanks
Alan
RE: Power Conditioning Equipment
This can't be the first bad experience that the manufacturer has had with such finicky equipment. That is the first place to inquire.
Bill
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"Why not the best?"
Jimmy Carter
RE: Power Conditioning Equipment
I have looked at the STACO Energy and UST equipment. Does anyone know of other vendors?
Thanks
Alan
RE: Power Conditioning Equipment
RE: Power Conditioning Equipment
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If we learn from our mistakes I'm getting a great education!
RE: Power Conditioning Equipment
Alan
Alan
RE: Power Conditioning Equipment
Didn't know that S&C was in that business, thanks for the info!
Scotty,
Looks like Waterford may not have a large enough unit, but thanks as well!
Alan
Alan
RE: Power Conditioning Equipment
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If we learn from our mistakes I'm getting a great education!
RE: Power Conditioning Equipment
Thanks
Alan
RE: Power Conditioning Equipment
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If we learn from our mistakes I'm getting a great education!
RE: Power Conditioning Equipment
Alan
RE: Power Conditioning Equipment
Alan
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"It's always fun to do the impossible." - Walt Disney
RE: Power Conditioning Equipment
RE: Power Conditioning Equipment
Liebert's "datawave" could be a magnetic solution. Bulky but reliable. Not too state of the art but very rugged.
Mitsubishi's static UPSs can work without batteries as power conditioners and can be stacked up to a few MVA. All other static UPSs in the USA need batteries, I believe.
You can also look at the M-G sets.
The question still remains, why would you want to do it when the customer should be doing it. But that is not your question at the moment. As stated before, installing a PC system just for the problem load will be much more economical.
Rafiq Bulsara
http://www.srengineersct.com
RE: Power Conditioning Equipment
Just exploring options at this point to see who has the equipment available. My first recommendation was certainly to correct for the specific equipment, but the customer says it is "plant wide".
First step is to get past the posturing and finger pointing so we can get down to a solution for the issue. I do believe that the customer is aware of what needs to be done to get the voltage regulation that are requesting, but would love for someone else to pay for it. Wouldn't we all.
Thanks
Alan
RE: Power Conditioning Equipment
After several weeks of voltage recordings, we found that the mins and max were approx. -.5% to +5%. Pretty good for service one would think. Had to chuckle when the customer complained about a dip to 456 volts. Asked for how long...the answer was a whole 8 milliseconds!
We are looking at simply changing the tap on the service transformer 2.5% to see if the customer can live with it. Should take it to about -2 and 3 to +2 and 3% if circuit load variations don't hurt us to badly.
Otherwise the customer has a problem to fix!
Thanks
Alan