Load Power
2010
 |
 Power relay SPDT 15A LOAD 24VDC COILOR 9V SONGLE5pcs $3.50 Time Remaining: 16d 17h 54m Buy It Now for only: $3.50 |
 NEW LOAD CONTROLS UNIVERSAL POWER CELL MODEL UPC $75.00 Time Remaining: 7h 38m |
 Power relay SPST 30A load Coil 12VOR 24V top mount x5 $9.99 Time Remaining: 16d 17h 53m Buy It Now for only: $9.99 |
 Load Controls Inc Power Cell Transducer PH 3 HG PH 3 HG PH3HG WARRANTY $150.00 Time Remaining: 8d 19h 17m Buy It Now for only: $150.00 |
 Power relay SPST 30A load 1 form A 48V coil Songle x5pc $14.99 Time Remaining: 16d 17h 54m Buy It Now for only: $14.99 |
 Power relay DPDT 5A load Coil 5VOR 12V pcb mount SRE series SONGLE5pcs $9.99 Time Remaining: 16d 17h 55m Buy It Now for only: $9.99 |
 Power relay SPDT 15A LOAD 12VDC COILOR 5V SONGLE5pcs $3.50 Time Remaining: 16d 17h 54m Buy It Now for only: $3.50 |
 GE POWER MARK MAIN LUG 125 AMP LOAD CENTER TLM612FCUD MOD 2 $35.00 Time Remaining: 15d 16h 43m Buy It Now for only: $35.00 |
 New Load Controls Power and Energy Meter 4 20ma KWH 2 $152.99 Time Remaining: 10d 23h 51m Buy It Now for only: $152.99 |
 Power relay DPDT 5A load Coil 9V pcb mount SRE Series SONGLE5pcs $12.99 Time Remaining: 16d 17h 55m Buy It Now for only: $12.99 |
 LOAD CONTROLS PH 3A 460V 30A 0 10v POWER CELL INV2349 $39.20 Time Remaining: 14d 23h 44m Buy It Now for only: $39.20 |
 LOAD CONTROLS INC POWER CELL TRANSDUCER PH 3A R $65.00 Time Remaining: 5d 21h 24m Buy It Now for only: $65.00 |
 Load Controls Inc Power Cell S Module PH 3 HHG WARRANTY $25.00 Time Remaining: 19d 16h 49m Buy It Now for only: $25.00 |
 Load Controls Inc Power Cell PH 3 460 V 40 Amp WARRANTY $30.00 Time Remaining: 13d 16h 48m Buy It Now for only: $30.00 |
 QVR 10A E SUPPLY LOAD VARIABLE POWER REGULATOR LNNLO $30.00 Time Remaining: 24d 13h Buy It Now for only: $30.00 |
 LOAD CONTROLS Power Cell Transducer PH 3A PH 3 HG PH3HG $245.00 Time Remaining: 23d 38m Buy It Now for only: $245.00 |
 Load Controls Inc PH 3 Power Cell Transducer 380V 20A PH3 CFC 1 94V 0 $40.00 Time Remaining: 16d 3h 24m Buy It Now for only: $40.00 |
 NEW LOAD CONTROLS UNIVERSAL POWER CELL MODEL UPC $330.00 Time Remaining: 7d 16h 14m Buy It Now for only: $330.00 |
 Load Controls Inc PH 3 Power Cell Transducer 230V 10A CFC 1 94V 0 $45.00 Time Remaining: 16d 3h 28m Buy It Now for only: $45.00 |
 MOTOR LOAD CONTROLS COMPENSATOR POWER CELL W METER $299.00 Time Remaining: 4d 4h 17m Buy It Now for only: $299.00 |
 REDUCED New Veris Hawkeye H421 Current Transducer 4 20 mA Loop Powered Lg Loads $129.00 Time Remaining: 8d 19h 55m Buy It Now for only: $129.00 |
 NEW LOAD CONTROLS POWER CELL PH 3A 350 460V 210A $89.00 Time Remaining: 29d 17h 51m Buy It Now for only: $89.00 |
 LANTECH LOAD CELL POWER SUPPLY BOARD 55030702A NEW $199.99 Time Remaining: 8d 23h 37m Buy It Now for only: $199.99 |
 Woodward Automatic Power Transfer and Load Con 9905 007 $299.00 Time Remaining: 12d 16h Buy It Now for only: $299.00 |
 0F9084 GENERAC POWER SYSTEMS LOAD CENTER $1,685.00 Time Remaining: 10d 20h 42m Buy It Now for only: $1,685.00 |
 OMRON EE SPX301 NPN voltage output Load power supply voltage 5 to 24 VDC $20.00 Time Remaining: 15d 6h 24m Buy It Now for only: $20.00 |
 LOAD CONTROLS INC PH 3A POWER CELL POWER TRANSDUCER $274.99 Time Remaining: 17d 18h 40m Buy It Now for only: $274.99 |
 POWER CELL SENSES 3 PHASE PWRLOAD CONTROLS P N PH 3A $125.00 Time Remaining: 22d 19h 51m Buy It Now for only: $125.00 |
 Load Controls Inc Universal Power Cell Motor Power monitor GENTLY USED $79.99 Time Remaining: 2d 14h 52m Buy It Now for only: $249.00 |
 LOAD CONTROLS INC PH 3A R POWER CELL 460V 30A 0 10V PH3AR $175.00 Time Remaining: 1d 19h 56m Buy It Now for only: $175.00 |
 LOAD CONTROLS 230V 40A 3 PHASE POWER CELL $159.99 Time Remaining: 28d 19h 9m Buy It Now for only: $159.99 |
 ABB ASEA QMAU 803 YM 321 001 Y BACK UP POWER SUPPLY UNIT QIPA 122 LOAD CELL $299.15 Time Remaining: 3d 7h 26m Buy It Now for only: $299.15 |
 Lambda Veeco LCS A 12 Regulated Power Supply 12VDC Output FULLY LOAD TESTED $80.00 Time Remaining: 13d 2h 9m Buy It Now for only: $80.00 |
 Load Control Inc LCI Power Transmitter PH 3A $185.00 Time Remaining: 19h 29m Buy It Now for only: $185.00 |
 Load Controls Inc Power Cell For V Load Controls PH 3 $299.99 Time Remaining: 12d 40m Buy It Now for only: $299.99 |
 Load Controls Transducer PH 3A R PH3AR Power Cell $240.00 Time Remaining: 22d 21h 52m Buy It Now for only: $240.00 |
 LOAD CONTROLS INC PH 3A POWER CELL POWER TRANSDUCER $249.99 Time Remaining: 13d 19h 3m Buy It Now for only: $249.99 |
 50pc TTi TR94 24VDC PC A 80A 14V load Power Relay SPST Coil24V $148.00 Time Remaining: 5d 9h 34m Buy It Now for only: $148.00 |
 1 LOAD CONTROLS PH 3A HG POWER CELL Q9 3 $199.99 Time Remaining: 12d 18h 22m Buy It Now for only: $199.99 |
 Load Controls Power Cell PH 3A R 260 V 20A 7207 $299.00 Time Remaining: 9d 19h 56m Buy It Now for only: $299.00 |
 Load Controls Model UPC Universal Power Cell $379.99 Time Remaining: 27d 21h 9m Buy It Now for only: $379.99 |
 Load Controls INC UPC FR Universal Power Cell $325.00 Time Remaining: 15d 20h 54m Buy It Now for only: $325.00 |
 Load Controls INC PH 3A Power Cell Power Transducer $200.00 Time Remaining: 15d 21h 17m Buy It Now for only: $200.00 |
 Load Controls INC UPC Universal Power Cell $325.00 Time Remaining: 15d 21h 34m Buy It Now for only: $325.00 |
 WATTSTOPPER POWER PACK 277 VAC 20A BALLAST LOAD B277E P $29.50 Time Remaining: 18d 18h 1m Buy It Now for only: $29.50 |
 EPT EMERSON POWER TRANSMISSION WM7000 LOAD MONITOR PLUS 120 240V $695.00 Time Remaining: 29d 23h 16m Buy It Now for only: $695.00 |
 Load Controls Inc Universal Power Cell UPC FR new $429.99 Time Remaining: 27d 21h 22m Buy It Now for only: $429.99 |
 Load Controls Inc Universal Power Cell UPC FR nib $479.99 Time Remaining: 27d 21h 26m Buy It Now for only: $479.99 |
 LOAD CONTROL INC MOTOR POWER SENSOR TP 1 $132.30 Time Remaining: 16d 6h 26m Buy It Now for only: $132.30 |
 LOAD CONTROLS UPC POWER CELL 3ph CT MODULE w COMM $199.99 Time Remaining: 23d 23h 51m Buy It Now for only: $199.99 |
 PMT AC MOTOR LOAD SURVEYOR POWER REPORTER MODULE $99.99 Time Remaining: 26d 22h 51m Buy It Now for only: $99.99 |
 Power One Load Booster TE 99 + 6x 5VDC 6A Power Supply HC5 6 OVP A $249.99 Time Remaining: 19d 1h 56m Buy It Now for only: $249.99 |
 Load Controls PH 3A Fast Response Power Cell Transducer $274.99 Time Remaining: 22d 1h 20m Buy It Now for only: $274.99 |
 Powers Fasteners 50506 Yellow 22 Cal Load 100 $19.99 Time Remaining: 4d 4h 18m Buy It Now for only: $19.99 |
Load Power
Power System Resonance
Hot vibes can result when harmonics and capacitors get together
Is it possible to install "Power Factor Correction Capacitors" and have PF get worse? It certainly is, and a starting place to understanding this puzzle lies in the distinction between Displacement PF (DPF) and Total Power Factor (PF). The penalty for not understanding the difference can be blown capacitors and wasted investment. Total PF and Displacement PF are the same in one basic sense: they are the ratio of Real Power to Apparent Power, or Watts to VA. DPF is the classic concept of power factor. It can be considered as the power factor at the fundamental frequency. Total Power Factor, abbreviated to Power Factor (PF), now includes the effects of fundamental and of harmonic currents (it is also referred to as True PF or Distortion PF). It follows that with the presence of harmonics, PF is always lower than DPF and is also a more accurate description of total system efficiency than DPF alone.
Strictly speaking, the term "Power Factor" refers to Total PF, but in practice can also be used to refer to DPF. Needless to say, this introduces some confusion into discussions of power factor. You have to be clear which one you're talking about.
Displacement Power Factor
Lower DPF is caused by motor loads which introduce the need for Reactive Power (Volt-Amp Reactive or VARs). The system has to have the capacity, measured in Volt-Amps (VA) to supply both VARs and Watts. The more VARs needed, the larger the VA requirement and the smaller the DPF. The cost of VARs is accounted for in a power factor penalty charge. Utilities often levy additional charges for DPF below a certain level; the actual number varies widely, but typical numbers are 0.90 to 0.95. To reduce VARs caused by motor loads, power factor correction capacitors are installed. Upstream system capacity, both in the plant and at the utility level, is released and available for other uses. Historically, this has been the gist of the PF story: a relatively well-known problem with a relatively straightforward solution.
Harmonics and Capacitors
Harmonics have had a dramatic impact on our approach to Power Factor correction. The motor and capacitor loads described above are all linear and for all practical purposes generate no harmonics. Non-linear loads such as ASDS, on the other hand, do generate harmonic currents. Take a plant which is step-by-step putting adjustable speed drives on its motor loads. ASDs generate significant harmonic currents (5th and 7th on six-pulse converter drives). Suddenly the fuses on existing PF correction caps start blowing. Since these are three-phase caps, only one of the three fuses might blow. Now you've got unbalanced currents, possibly unbalanced voltages. The electrician replaces the fuses. They blow again. He puts in larger fuses. Now the fuses survive, but the capacitor blows. He replaces the capacitor. Same thing happens. What's going on? Harmonics are higher frequency currents. The higher the frequency, the lower the impedance of a cap. The cap acts like a sink for harmonic currents.
Power System Resonance
In a worst-case scenario, the inductive reactance (XL) of the transformer and the capacitive reactance (XC) of the PF correction cap form a parallel resonant circuit: XL= XC at a resonant frequency which is the same as or close to a harmonic frequency. The harmonic current generated by the load excites the circuit into oscillation. Currents then circulate within this circuit which are many times greater than the exciting current. This so-called "tank circuit" can severely damage equipment, and it will also cause a drop in power factor. Perversely, this resonant condition often appears only when the system is lightly loaded, because the damping effect of resistive loads is removed. In other words, we have what the audio buffs call a "high Q" circuit.
Imagine coming to work on a Monday and seeing the insulation on your cables melted off. How can this happen over a weekend when there was hardly any load on the system? Has Ohm's Law been overruled? Not quite. Your power system just spent the weekend tanked out on the Harmonics. It was quite a party, but now comes the clean-up.
Start with Harmonics Mitigation
The correct solution path starts with measuring and mitigating the harmonics generated by the drives. (One useful tool for measuring harmonics and capacitance is the Fluke 43B Power Quality Analyzer.) Harmonic trap filters would generally be called for. These trap filters are installed locally on the line side of the drive. Their effect is very much like the traditional PF correction cap, in two senses: they reduce DPF as well as PF, and also they localize the circulation of the problem harmonics (generally the 5th). Harmonics mitigation and traditional DPF correction should be addressed as one systems issue. In other words, manage Total PF, not just DPF.
About the Author
A graduate of Oakland University (Rochester, MI), Steve Glad is a writer with Structured Information (http://www.strucinfo.com/) in Needham Heights, MA. He frequently writes about industrial technology topics.
Does Uninterruptible Power Supply Modifier Load Power?
When you use a 500VA UPS to supply back up power to a 50VA load at 120VAC, does the current increase on the circuit? Instead of being .416A which is drawn by the load, is the circuit now drawn 4.58A with the UPS added?
Or should the UPS has no effect on the circuit?
No, the VA rating of a UPS has to do with the power it can supply in the event of a power failure. That is, without wall power, it can supply power at that rating for, say, five minutes.
The UPS would only draw power to charge the battery and supply any internal circuitry.
ONE Man EZ Load loads a large emergency / backup power generator onto a pickup truck
