Installation, Operation & Maintenance Manual
IM-502
9
Motor Wiring & Installation
1. Proper Lockout/Tagout procedures should always be followed as discussed in the
Safety & Hazard Warnings
section. Verify that no
power is on the circuit to which the fan is being connected.
Run appropriately rated wiring for the installation method to the junction box located within the motor housing; only ½”
knockouts available.
Downblast Fans: The electrical supply is routed through conduit between the curb cap and motor compartment.
Upblast Fans: The electrical supply is routed through the vent tube.
See images below for electrical routing.
a. Refer to the accessory installation portion towards the end of this manual for additional wiring instructions for various wired
accessories.
2. Leave enough slack in the wiring for maintenance accessibility.
Electrical Information
1. Check the wiring diagrams on the motor for connections.
2. The motor is factory set at the voltage marked on the fan
nameplate. Check the line voltage with the nameplate voltage
and wiring diagrams.
3. The main power wiring should be sized for the ampacity shown
on the dataplate. Size wires in accordance with the ampacity
tables in Article 310 of the National Electrical Code. If long wires
are required, it may be necessary to increase wire size to prevent excessive voltage drop. Wires should be sized for a maximum of
3% voltage drop.
4. Disconnect switches are not fused. The power leads must be protected at the point of distribution in accordance with the fan
dataplate.
5. On fans without a thermal protector integral to the motor (refer to unit or motor dataplate to determine if protector is present) a
separate overload device is required. Refer to Sections 430-32 of the N.E.C. for sizing.
6. All units must be electrically grounded in accordance with local codes or, in the absence of local codes, with the latest edition of the
National Electrical Code (ANSI/NFPA 70). A ground lug is provided as standard in the unit terminal box. Size grounding conductor
in accordance with Table 250-95 of the National Electrical Code. DO NOT use the ground lug for connecting a neutral conductor.
7. Supply voltage to the power ventilator should not vary by more than 10% of the value indicated on the unit dataplate. Phase
unbalance must not exceed 2%.
Failure of motor due to operation on improper line voltage or with excessive phase unbalance constitutes product abuse and
may cause severe damage to the unit’s electrical components.
WARNING
1. Use copper conductors only.
2. Protect wiring from sharp edges. Leave some slack in the line
to prevent damage.
CAUTION
Motor
Junction
Box
Conduit
Field
Wiring
Motor
Junction
Box
Field
Wiring
Vent
Tube
