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RWD3M
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Pete.
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Nowhere near. A 3hp motor will pull about 13amps. That one's about 1.5kw/2hp or a bit less.
EDIT: example below
Most useful, thanks a lot @Blobber
I did wonder as the motor we spoke about during the last few days is rated at 8 amps, it's also rated at 1.5hp on the plate.
Pete.
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This calculation is fine for resistive loads but not inductive loads as in an induction motor.
What is an inductive load?
In electrical engineering, an inductive load is a type of electrical load that stores energy in a magnetic field. Inductive loads include motors, transformers, and inductors. When current flows through an IL, a magnetic field is created that stores energy. This energy is released when the current flow stops or changes direction.
How does it affect power quality (PQ)?
Inductive loads affect PQ by introducing reactive power into an electrical system. Reactive power is the power that an IL consumes but does not convert into useful work. This can cause a decrease in the overall PF of the system. A low power factor (PF) can result in increased losses, decreased efficiency, and increased power source costs.
So you can't find the motor's power rating (output power) by multiplying the voltage by the amps because that will give you the power that the motor is consuming, not the power that it is producing, which is somewhat less.
Guineafowl
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Motor HP is a ‘power class’, or nominal value. At times, they’ll pull much more current than you’d expect, sometimes much less. Full load amps might not correspond with the kW/HP rating.
1.5 kW (2 HP) is about right - a typical 1ph, 4 pole of that rating would have about 8 amps stamped on the plate. Eg:
1.5 kW (2 HP) is about right - a typical 1ph, 4 pole of that rating would have about 8 amps stamped on the plate. Eg:
Pete.
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Aha! Well spotted, I didn't see that.
Guineafowl
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No-one’s used power factor at all.You can use it as a divisor or multiplier:
P = VI.(cosphi)
or
I = P/V(cosphi)
waddycall
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Haha - you’re right. It was a long day. I saw the 0.74 as PF and didn’t read it fully
You can use it as a divisor or multiplier:
P = VI.(cosphi)
or
I = P/V(cosphi)
