9
installation
Motor Wiring
For maintenance/safety purposes, SPX recommends a lockout
type disconnect switch for all mechanical equipment. In addition
to a disconnect switch, the motor should be wired to main power
supply through short circuit protection, and a magnetic starter with
overload protection.
Wire motor leads as shown on the motor nameplate matching the supply
voltage. Do not deviate from the motor nameplate wiring.
Internal space heaters may be present, depending upon the motor manufac-
turer. For space heater operation and wiring refer to the Marley “Fan Motor”
User Manual” User Manual
Z0239042
.
Either of following symbols may be shown on the motor nameplate –
Δ, Δ Δ
,
Y
, or
YY
. These symbols represent how the motor is constructed on
the inside and in no way have anything to do with a Delta or Wye electrical
distribution system serving the motor.
When using a starter:
• Set motor overload protection to 110% of motor nameplate amps. This
setting allows the fan motor to operate during cooler weather. During
cooler weather it is common for the motor to draw 6 to 10% higher than
nameplate amps. High amps are common during tower commissioning
when the tower is dry and the ambient air temperature is cool.
Do not start the motor(s) more than four to five times per hour. Short
cycling the tower will cause fuses, breakers or O.L.s to operate and
will decrease motor life.
When using a two-speed starter:
• Motor rotation must be the same at slow speed and high speed.
• Single winding motor requires a starter with a shorting contactor.
• Two-winding motor requires a starter with out a shorting contactor.
• All two-speed starters must have a 20 second time delay relay when
switching from high speed to low speed.
Do not start the motor more than four to five times per hour (each
low speed start and each high speed start count as one start).
Warning
Note
Note
