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      11-24-2021, 07:47 AM   #53
dscabra
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Quote:
Originally Posted by Mingwan View Post
I guess we have our replacement for displacement…it’s e-muscle…
Or in EV terms:

Horsepower (hp) = Voltage x Amperage x % EFF x power factor x 1.73/746

Where:
Voltage is the average of the three voltages measured: (A-B + A-C + B-C)/3

Amperage is the average current of the three phase measured: (A+B+C)/3

% EFF is motor efficiency per motor nameplate

Power factor is the ratio of true power (kW) to apparent power (kVA). In the absence of power factor measurement tools, a rule of thumb is to estimate power factor at 0.85

1.73 is a constant used when calculating three-phase power

746 is the constant for converting watts to horsepower (746 watts = 1 Hp)

Example: How much horsepower is a 25 hp motor producing at 472 volts and drawing an average of 20 amps per phase with a motor nameplate marking of 90 % efficiency?

Horsepower (hp) = Voltage x Amperage x % EFF x power factor x 1.73/746

= 472V x 20A x 0.90 x 0.85 x 1.73/746 = 17 Hp

Last edited by dscabra; 11-24-2021 at 07:52 AM..
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