electrical submersible pump motor efficiency
electrical submersible pump motor efficiency
(OP)
I have a pump rated to deliver 75 gpm at a head of 740 feet
coupled to motor rated 20 Hp
The pump currently discharges 60 gpm and draws an average of 47.6 amps on the phases with 230 volts.
Question is how do i compute for the effeciency?
would it be-
[Pout = 14920 (from 20 Hp)] /
[Pin = A (from meter) * V (from meter) * 1.73 *.8 pf]
id get = 98%
or:
from the pump power curve, from the manufacturer, i've plotted the kw, against the current discharge of 60 gpm
ive got a value of 12.4kw = P2
P2 / P1 =
12.4kw / 15kw = 83% = p1 by the way is the pump motor requirement given from the manufacturers curve...
im confused. thanks!
coupled to motor rated 20 Hp
The pump currently discharges 60 gpm and draws an average of 47.6 amps on the phases with 230 volts.
Question is how do i compute for the effeciency?
would it be-
[Pout = 14920 (from 20 Hp)] /
[Pin = A (from meter) * V (from meter) * 1.73 *.8 pf]
id get = 98%
or:
from the pump power curve, from the manufacturer, i've plotted the kw, against the current discharge of 60 gpm
ive got a value of 12.4kw = P2
P2 / P1 =
12.4kw / 15kw = 83% = p1 by the way is the pump motor requirement given from the manufacturers curve...
im confused. thanks!





RE: electrical submersible pump motor efficiency
= 11.24 HP
= 8381 Watts (Work done per minute)
47.6 A x 230 V x 1.73 x .8pf = 15152 Watts. (Power consumed)
8381 Watts/15152 Watts = 55% efficiency.
Possible error sources:
Your dynamic head may be greater than 740 ft. Your voltage may be different. If your currents are not equal you may expect greater than normal heating losses in the motor. Your power factor may be lower than the assumed 0.8 Power factor often drops when a motor is less than fully loaded.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: electrical submersible pump motor efficiency
Your question suggests you want the efficiency of the motor alone. First method gave the efficiency of the motor.
RE: electrical submersible pump motor efficiency
Submersible motors are not known for high efficiency or good power factor.
Otherwise, as stevenal said, you need to decide what efficiency you are looking for.
David Castor
www.cvoes.com
RE: electrical submersible pump motor efficiency
Measuring voltage and current and assuming a power factor will make enough of an error that the rest of the calculation is pointless.