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| Thread ID: 107817 | 2010-03-02 23:45:00 | Phase Angle - what is it? | Agent_24 (57) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 863281 | 2010-03-03 07:42:00 | The penalty is that you are paying for power that you haven't had. Most fluorescents have a capacitor to help restore their power factor misdemeanours caused by the inductive choke. | R2x1 (4628) | ||
| 863282 | 2010-03-03 07:57:00 | The penalty is that you are paying for power that you haven't had. Most fluorescents have a capacitor to help restore their power factor misdemeanours caused by the inductive choke. The capacitor raises the power factor reducing the losses the electricity supplier would incur by supplying VA and charging Watts. |
PaulD (232) | ||
| 863283 | 2010-03-03 07:59:00 | Is that true for domestic users here? The traditional metering has been kWh with no penalty for low power factor. I think most suppliers have a clause in their terms and conditions about power factor, but in practice it most likely only applies to industry and businesses :- Genesis: Some technical requirements relating to electricity In relation to your electricity supply, you agree that: * the power factor shall not be less than 0.95 lagging each month; www.genesisenergy.co.nz Westpower: 6 Power Factor (PF) Correction 6.1 General Requirements The power factor of a customer’s installation shall be maintained at not less that 0.95 lagging at any time. The power factor shall be determined by Westpower’s instruments and shall be assessed on the average value over a 30-minute period. Westpower reserves the right to charge a penalty in addition to the normal electricity charges when it is found that an installation is maintained at less than 0.95 lagging power factor. www.westpower.co.nz Since most households would have mainly resistive loads, like ovens lights and heaters, then a PF below 0.95 is unlikely, but with so many inverter heat pumps these days,and other appliances with motors, it could be worthwhile having a test carried out. I'm not sure whether unbalanced single phase domestic distribution from the 3 phase supply causes a lower power factor, or just voltage/current unbalance The lines companies would usually ensure that each of the phases are as balanced as possible, in terms of the number of households fed from each phase. |
Terry Porritt (14) | ||
| 863284 | 2010-03-03 08:14:00 | Yep; the red (or positive) electricity is used for heating and pumps etc. The black (or negative) electricity is used for refrigerators and vacuum cleaners. The newer brown or blue multicoloured electricity is reserved for TVs, traffic lights and Xmas decorations. Get the colours unbalanced and the race relations officer will be banging on your door. |
R2x1 (4628) | ||
| 863285 | 2010-03-04 08:27:00 | Is that true for domestic users here? The traditional metering has been kWh with no penalty for low power factor. That's the problem, power meters can't compensate for Power Factor error so you get charged for more power than you are actually using. I don't know about the modern electronic meters, they could be smart enough to compensate but there's no incentive for the power companies to do that, they make more money from PF error. In answer to tweak'e, yes, capacitor banks are still used, there is no real alternative. I did some work in a major TransPower substation/switchyard last year and they had megawatts of PF correction in place with computer controlled real-time correction. It is much more efficient than switched capacitor banks, but more expensive for sure. Cheers Billy 8-{) |
Billy T (70) | ||
| 863286 | 2010-03-04 09:06:00 | Nice explanation by R2x1 Agreed. Reading it I realised I was already on the right track as I had read about Power Factor before but had never heard the term "Phase Angle" I think I understand it all a bit better now anyway! So it does make sense to have a good Power Factor, even in your home? Maybe I should look into buying more PSUs with Active PFC :lol: |
Agent_24 (57) | ||
| 863287 | 2010-03-04 09:29:00 | Without a good power factor, you have some "wattless power", it costs a lot more than it performs. Unless your domestic situation is most unusual, it is likely that someone near you is messing things up, and you are paying too much for your power as a consequence. You could ask the power supplier to check the power factor if you think it is out of line. As Terry said, they are (or at least used to be) obliged to keep it up to par, so they will fix it and save you some money each month. Some neighbouring user is likely to get a "see me after school" note from the supply co, requiring them to fix up their act. No way should you have to pay to fix up a power supply that is off spec., nor should you have to pay for power you are not really using. (Of course, if the distortion is occurring on your premises, you will be the one getting a fix it order :( but as Billy T said, it is unlikely in domestic installations and as Terry noted, the specs appear to be a lot better than you are getting.) |
R2x1 (4628) | ||
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