SPX Cooling Technologies MARLEY HP700 - Manual (Page 11)

11
Motor Load
The corrected horsepower should be close to but not exceed the
contract horsepower specified by Marley. Determine corrected
horsepower using the following equation.
Actual volts and amperage must be obtained with the fan running
and the specified rate of water flowing over the tower after the motor
and Geareducer have reached operating temperature (approximately
30 minutes of operation).
Measurements taken on motors operating with Variable Fre-
quency Drive controls may read up to 15% high from errors in
measuring the approximated sine wave. Instruments capable of
measuring a squared off wave form accurately should be used
for measuring power in this situation.
Do not exceed 30 sec/hour total motor starting time as motor
may overheat.
Note
VOLTS
N
= Nameplate Volts
AMPS
N
= Nameplate Amperage
HP
N
= Nameplate Horsepower
DENSITY
D
= Design Air Density
HP
C
= Corrected Horsepower
VOLTS
A
= Actual Volts
AMPS
A
= Actual Amperage
DENSITY
A
= Actual Air Density
VOLTS
A
× AMPS
A
× DENSITY
D
VOLTS
N
× AMPS
N
× DENSITY
A
HP
C
= × HP
N