User manual

9
Caution
Forweldedconnectionsprotectadjacentareasfromexcessiveheat
andsparksordamagemayoccur.
7. Wire motor(s) and recirculation pump(s) in accordance with wiring dia-
gram.
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 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.
➠
Installation
Warning
Note