Power Usage-Voltage and Current Interaction
Power Usage-Voltage and Current Interaction
(OP)
We are doing a power quality monitoring at the main service. Atsome particular time of the day a voltage sag happened which the main 347V drpped down to 120V and caused all the equipment to shutdwon for around 16Cycle.
I understaned the basic rule of power P=V*I .Is this true for all loads?
any type of load?
Heating lopads,motors...?
Is there an instance whcih if the voltage dropps the current droops too?Well obviously the same power would not be delivered, just need some expert feedbacks.
Thank you,
I understaned the basic rule of power P=V*I .Is this true for all loads?
any type of load?
Heating lopads,motors...?
Is there an instance whcih if the voltage dropps the current droops too?Well obviously the same power would not be delivered, just need some expert feedbacks.
Thank you,






RE: Power Usage-Voltage and Current Interaction
RE: Power Usage-Voltage and Current Interaction
How aout HVAC systems or Pumps or air conditioners,motors...
How to caractorize them?
RE: Power Usage-Voltage and Current Interaction
RE: Power Usage-Voltage and Current Interaction
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Sometimes I only open my mouth to swap feet...
RE: Power Usage-Voltage and Current Interaction
what range of voltage?where can I get the detailed info?
How about HVAC systems or Pumps or air conditioners?
Well pumps or compressors are motors..
when the voltage dropes down and current goes up,is this the indication that most of the plant loading is constant power loads such as motors?but if the voltage goes lower than certain vaue, then it might behave as constant impedance right?
RE: Power Usage-Voltage and Current Interaction
Resistive loads will shed to the equation Power = V2/R and so are definitely not constant power. But of course the current will drop linearly.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Power Usage-Voltage and Current Interaction
Regarding P=V*I, for AC power, P=V*I*pf where the power factor (pf) is 1 for resistive loads and less than 1 for motors. For balanced 3 phase, P=V*I*pf*1.732 where V is line to line volts and I is line current.
For additional information about what happens to motors when voltage droops, look at: http://www.reliance.com/mtr/pwrspymn.htm.
RE: Power Usage-Voltage and Current Interaction
RE: Power Usage-Voltage and Current Interaction
wELL, I NEED TO KNOW what type of load with this charactristics can cause a voltage sag of 35% for 285ms .
There is not a huge motor in the plant?
and the problem suspected to be initiated inside the plant.
RE: Power Usage-Voltage and Current Interaction
RE: Power Usage-Voltage and Current Interaction
RE: Power Usage-Voltage and Current Interaction
Can I do this?
RE: Power Usage-Voltage and Current Interaction
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com