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Full load current greater than nameplate value 1

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Marcus750

Mechanical
Mar 27, 2019
5
I have a pump motor that is measuring 9A on full load and the nameplate value is 3A. I'm no doubt opening myself up for derision, but What does this mean?

Thanks
 
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It doesn't seem possible to be honest as this is three times the rating and you would expect the motor to significantly overheat / burn / smoke.

Are you sure you're reading the right data? Sometimes you have different voltages / windings and hence different currents. A picture of the nameplate and what voltage and where you're measuring the voltage would help ( single phase, three phase, ??)

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Only other thing though is that for start up the load can go 4-6 times higher than Full load for a short period as it speeds up. That is quite normal.

Are those steady state operating readings?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
At 9A that's approaching locked rotor amp value. Has the viscocity of the material being pumped changed?
 
A motor which is mis-connected can run at very high slip with very high current if a motor design to operate in delta is wired in star (wye). Usually the overload proetction trips the motor - at 300% overload it should be tripping in about 30s - 40s or so.
 
Can you describe the start/stop cycles? How long does the pump run, and does it draw 9A continuosly? How long are the pauses between pumping actions?
 
Or tripped the overload...

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.)
 
Sadly Our OP is a two post master and last logged in to post the question.

Marcus - If you ever come back and read these responses if there is a next time please don't leave it so long...

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Hi All, Firstly a big thank you to all who replied to me query and apologies for the delay in responding as I was on holiday for to weeks. Initially when I had the pump on manual test it was displaying the aforementioned readings, but when I tested again it was tripping; so a fault with the motor. Looks like we're going to get a new LTHW pressurisation unit.

 
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