pump draws more ampere
pump draws more ampere
(OP)
I have a water cooled condenser pump (90kw) and secondary pump (45kw). Both are working in 50 hz frequency. Condenser pump draws 169A and secondary draws 64A.as per the equation why condenser pump draws more amps? See the equation.





RE: pump draws more ampere
Diffe re b t voltage at the pump than the nominal voltage.
Actual motor efficiency different than 0.9.
You haven't included power factor.
Motor rating and power used are not the same thing. Where does 90 and 45 come from? If it's not the shaft power used then it's not the right figure.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: pump draws more ampere
Regards
Ashtree
"Any water can be made potable if you filter it through enough money"
RE: pump draws more ampere
RE: pump draws more ampere
Regardless of any equations or other info, the name plate maximum current is the number you must follow. That is the actual current running in your motor's windings. Exceeding it means you're over working the motor and it is going to be running hotter and at a less forgiving operating point.
Your condensate pump should not be drawing more than 163A, but it is drawing 169A. It is good that you are investigating it!
Things that can cause this:
1) The voltage being supplied is below the desired value. For every bit lower the voltage is below the 380V on the plate, more current will be required by the motor. Unfortunately more current automatically means more heat in the motor.
What is the actual voltage between all phases? (Exercise caution measuring it!)
2) Voltage very much higher than the nameplate will also cause higher current as the motor magnetics will be saturating.
3) The frequency being higher than 50Hz would also lead to higher current because the motor would be trying to spin faster and pump more. This is likely not the issue unless your power supply is poorly controlled. It would be a little more likely if you're on a local generator that is perhaps running a bit too fast.
4) The pump is loaded more than it should be. This is possible if, in any way, more flow is occurring than designed for. This would be because there is less restriction in the system then there should be. Perhaps a throttling valve to limit the flow to below overloading the motor has been opened fully in an attempt to 'get more performance' and instead will just lead to a shorter motor life. Other possibilities might be more demand than usual in the condenser circuit, again allowing more than expected flow. Do you have any flow gauges or any way to determine the flow? Folks in here can help you if you know the flow and have a pump-plate picture that is readable. (Your motor plate pictures have bad glare that makes them just barely readable.)
Keith Cress
kcress - http://www.flaminsystems.com
RE: pump draws more ampere
RE: pump draws more ampere
So you're running your big motor at 104%. Not great but in reality will survive for a while but you will reduce operating life and it may trip on excess amps or high temperature.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: pump draws more ampere
Without pump data it's all guess work.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: pump draws more ampere
It doesn't.
Therefore look at the pump duty first before looking at alk the other things mentioned above.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: pump draws more ampere
Its a common problem when running at end of curve...
Ash Fenn
www.cdrpumps.co.uk
RE: pump draws more ampere
as design, 960 gpm is the flow rate, but i will check the actual flow.
RE: pump draws more ampere
RE: pump draws more ampere
Keith Cress
kcress - http://www.flaminsystems.com
RE: pump draws more ampere