I borrowed a power analizer meter from work over the weekend and was amazed at how poor my power factor at the wash actually was. The goal here is a power factor of 1. Mine was as low as -.5 and the best I saw it was around .56. Keep in mind that when it was at .56 there were no pumps running, no customers in the wash, just a few lights and coin box heaters running. I had a 5KVAR capacitor box laying around so I put it on a circuit breaker and turned it on and off at different times to see what it would do. This is a small capacitor so it didn't do a lot, but it did raise my power factor by about .2 and drop my total amperage by a couple amps on each leg. I am now in the process of buying some more capacitors to see if I can get my power factor very close to 1. I think there is a huge potential for savings here and the capacitors can be found on ebay for less than $200 in many cases. Have to be careful not to over correct the power factor though which is just as bad. The meter I was using cost about $7000, but I am sure there are people who can come to your wash and measure this for you.
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Power factor correction
- Thread starter sparkey
- Start date
Sparky, this seems like one of things like the more you know, the more you realize, you don't know. First questions: 1. What exactly is power factor? 2. How important is it? There seem to be a lot of washes happily running with poor factors. 3. What guestimate of savings would there be by raising the factor? Inquiring minds want to know.
Indiana Wash
Member
Check out this link for the technical description of power factor http://en.wikipedia.org/wiki/Power_factor
In short it basically means the voltage and current are out of phase so less work gets done with the amount of energy used. The power company still bills you for all this power, you just don't get efficient use of the power you pay for. Induction motors or other inductive loads are terrible for messing up power factor. This power factor can be corrected though by simply adding capacitors or inductors depending on which way the power factor needs to go. It is usually capicitors that you need. I have seen different devices on this forum that say they save power. Basically they are capacitive devices you wire across your 3 power legs. Some of them are quite pricey, however you can buy the 3 phase capacitor boxes on places like ebay for a couple hundred bucks with much more correction ability. The capicitors are rated in kvars. The higher the kvar rating the more correction they will do. You have to be careful though that you don't over correct your power though or you will drive you power factor to far in the opposite direction and cause the same effect. This is why you should use a meter of some kind to actually measure your power factor. There are 2 ways to add capacitors. You can add they across your incoming power lines to correct your entire system, or you can add them across specific motors on the motor side of the starter to correct the power factor while that specific motor is running. Since induction motors lower you power factor, adding capacitors across the motor side of the motor starter is a common practice. That way when the motor is not running you don't risk over correcting the power factor. I am not sure on the exact savings, but with the little capicitors (5kvar) I added for experimental purposes I saw the over all current drop 2 - 3 amps and the power factor raise by .2. Remember you goal on the power factor is 1 and I was running as low as .2 at times.
In short it basically means the voltage and current are out of phase so less work gets done with the amount of energy used. The power company still bills you for all this power, you just don't get efficient use of the power you pay for. Induction motors or other inductive loads are terrible for messing up power factor. This power factor can be corrected though by simply adding capacitors or inductors depending on which way the power factor needs to go. It is usually capicitors that you need. I have seen different devices on this forum that say they save power. Basically they are capacitive devices you wire across your 3 power legs. Some of them are quite pricey, however you can buy the 3 phase capacitor boxes on places like ebay for a couple hundred bucks with much more correction ability. The capicitors are rated in kvars. The higher the kvar rating the more correction they will do. You have to be careful though that you don't over correct your power though or you will drive you power factor to far in the opposite direction and cause the same effect. This is why you should use a meter of some kind to actually measure your power factor. There are 2 ways to add capacitors. You can add they across your incoming power lines to correct your entire system, or you can add them across specific motors on the motor side of the starter to correct the power factor while that specific motor is running. Since induction motors lower you power factor, adding capacitors across the motor side of the motor starter is a common practice. That way when the motor is not running you don't risk over correcting the power factor. I am not sure on the exact savings, but with the little capicitors (5kvar) I added for experimental purposes I saw the over all current drop 2 - 3 amps and the power factor raise by .2. Remember you goal on the power factor is 1 and I was running as low as .2 at times.
Emerald in NJ
New member
I am very curious about this. I am trying to cut my electric bill down every way I can. Is anyone familiar with this device called a Black Hawk box? http://blackhawkenergysaver.com/ This sounds like it might be a capacitor like Sparkey is talking about but I am not an electrician and actually know very little about how these things work.
