motor call

markythesparky · May 17, 2016

Hi guys,

Could you clarify some thing for me?

If I've got an 1100w 230v motor running a pump, but don't know the power factor as its not listed on the rating plate, how can I work out overload rating?

David M · May 17, 2016

You can calculate it.

For a quick calc try this site

Power factor correction calculator

markythesparky · May 17, 2016

That's no good as I want to know the FLC and haven't got the power factor.

Spoon · May 17, 2016

What info is on the motor plate? Usually the FLC and power factor are on.

Lucien Nunes · May 17, 2016

1.1kW on a motor plate means mechanical output power, not electrical input, so to calculate FLC you would need not only voltage and pf but also efficiency, which is not usually stated. But FLC is, Like Spoon I am surprised it is not on your motor unless your plate is completely missing. It will be around 9A for single-phase 230V depending on age and speed.

markythesparky · May 23, 2016

the rating plate has P1 as 1.1kw. there is no power factor and no efficiency rating listed. this is why I'm having problems. I've come across this before with the same pumps (Starite).

in the end I had to get the pump supplier to find out for me. seems daft that I can't work it out on site.

Lucien Nunes · May 23, 2016

P1 is 1.1kW? That's confusing; 1.1kW is the standard motor size that replaced 1.5hp (output), but P1 is input power so it's a smaller motor than that and likely lower FLC than the 9A I suggested above. But it's eccentric for them not to state the FLC, the figure an installer most often wants to know along with voltage.

markythesparky · May 23, 2016

I agree. this is why the confusion.

Marvo · May 23, 2016

markythesparky said:
the rating plate has P1 as 1.1kw. there is no power factor and no efficiency rating listed. this is why I'm having problems. I've come across this before with the same pumps (Starite).

in the end I had to get the pump supplier to find out for me. seems daft that I can't work it out on site.

I'm also confused and wondering if they're correct saying the 1.1kW is actually P1.... I can't believe they could supply a motor with so little relevant info on the plate unless they're doing something shady like punting OEM stock to end users. I'd be on the phone or emailing the suppliers or agents for clarification unless there was a crystal clear and useful on-line spec sheet available.