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Current measurement without concurrent phase-to-phase voltage measurement, especially when determining "actual" load, can be misleading! What are the corresponding ph-to-ph voltage measurements? Do you want to know actual load with, or without, the benefit of electrical instrumets...

Rahul, I strongly disagree! The starting current, as well as breakaway torque, are functions of only the motor's design parameters. However, the available acceleration torque determines the time to accelerate the driven machine from standstill to full speed. Acceleration torque is a...

If a US-design, the data is available on the nameplate, in the former of a multiplying factor. The factor has a code letter, i.e., ... D, F, G, ... etc, which is listed in the NEC. It wll reveal the inrush kVA per Hp. If for general information, then the rms starting current may be 5 to 6...

Spraque had a ULN series of IC's specifically for Automotive Lamp Failure detection. Regards, Phil Corso, PE Boca Raton, FL [[email protected]] ([email protected]) {[email protected]}

Was your problem resolved? Regards, Phil Corso, PE Boca Raton, FL [[email protected]] ([email protected]) {[email protected]}

Amit, Was was your problem resolved? Regards, Phil Corso, PE Boca Raton, FL [[email protected]] ([email protected]) {[email protected]}

Replying to Bongiwe's Apr 11, 10:53am query: 1) Which circuit are you using... Transistor? or Op-Amp? 2) What do you mean "amplifier is operating alright"? 3) Does your detection circuit consist of two C'c and an L arranged in a Pi configuration? If so then amplication factor is...

Because you haven't stated what the values were, nor how they were obtained! By power measuing instruments? Or by calculation of measured paameters, i.e., phase-phase volts, phase-neutral volts, line-amps, power factor? Regards, Phil Corso, PE Boca Raton, FL [[email protected]]...

What are your input and output measurements? Regards, Phil Corso, PE Boca Raton, FL [[email protected]] ([email protected]) {[email protected]}

Amit, re: ur query on starting time: 1) The uncoupled starting time for a 2-pole motor of the size you have is about 3 to 5 seconds. 2) Add two or three seconds if coupled to an "unloaded" (and I stress unloaded) rotary compressor or pump! Cautionary Note: The above is solely based...

What alarm flags are displayed? Regards, Phil Corso, PE Boca Raton, FL [[email protected]] ([email protected]) {[email protected]}

Amit, I don't question your veracity, but, the locked-rotor value(s) are not realistic. That said, here is the formula: VoltDrop=SQRT(3)xIsxLx[RxCos(theta)+XxSin(theta)]x10E-3, where: Is = Starting current, Amps. L = Circuit length, Meters. R = Cable Resistance, Ohms/km. X =...

Responding to Amit Roy's Wed, Mar 26, 5:04pm, query: The calculation is straight forward. But, before answering, please confirm the following: Motor Rating: 1,500kW, 6.6kV, Amp ?, pf 0.9! Locked-rotor test data is unclear. Do you mean that when tested at locked-rotor, the applied...

Further to my earlier reply: A pump operating near shutoff is not operating at full-load. Lookup the "fluid" Hp formula! Regards, Phil Corso, PE Boca Raton, FL [[email protected]] ([email protected]) {[email protected]}

Three comments: 1) The correct equation for input power is: Pin = Sqrt(3) x Vpp x I x PF, where Vpp = ph-to-ph volts. I = Line current. PF = Power Factor. 2) The equivalent current is not Iavg, but instead, it should be obtained from the square root of the (sum of the...

Starting current is determined by the motor's "locked-rotor" parameters. Typically, a value is supplied by the manufacturer that relates the starting current in multiples of full-load current. That factor is called the starting-kVA per rated-Hp multiplier. The effects upon the power system...

Please provide detail, such as: 1) Hp, Volts, speed, starter-type, size, type, & length of downhole feeder! 2) What setup are you using to measure "powerfactor?" Are you using a 3-phase Watt/Var meter? Or are you monitoring individual phases? 3) What are service parameters? 4)...

Shahid, I apologize for reaching you via the List, but e-mail address I received didn't work. Please retry with your Fax No. The point I was trying to make was that I/O Diagnostics has far greater impact on SIS (even Traffic Control) performance, not Redundancy... especially not TMR...

Anand, "Hazard Prevention" magazine is published by AS Watermam Inc. Their tel # is, 508-336-8879, and their e-mail is : [email protected] Regards, Phil Corso, PE Boca Raton, FL [[email protected]] ([email protected]) {[email protected]}

Anand, I'm notclear about what you are proposing. If you want diversity of viewpoints, then, checkout my approach. Based on I/O diagnostics, it has been published in The Journal of the System Safety Society magazine: "Hazard Prevention" Vol 35, No. 3, 3rd Qtr 1999. My paper is...