SPX Cooling Technologies CoolingTower Marley MCW - Manual (Page 8)

8
Fasteners and components provided by others that are to be attached
to the tower must be compatible with the cooling tower materials—
i.e. fasteners in a stainless steel cold water basin must be stainless
steel.
Do not support your pipe from the tower or inlet connection—support
it externally.
7. Wire motor in accordance with wiring diagram.
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.
Motor Wiring
Wire motor leads as shown on the motor nameplate matching the supply
voltage. Do not deviate from the motor nameplate wiring.
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 more than six 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 contac-
tor.
Installation
Caution
Warning