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Operation and Unit Start-Up
Electrical Connections
The electrical supply must be compatible with the fan motor voltage, phase and amperage capacity. The electrical
supply line must be properly fused and conform to local and national electrical codes.
For direct drive units, the electrical supply may be routed internally and exit through a hole provided in the fan
housing if an optional service disconnect switch is provided.
For belt drive units, the electrical supply line may be routed internally and exit the fan housing through a hole
provided below the belt tube opening. The electrical supply line should then be either: (1) connected to an optional
service disconnect switch, or (2) wired directly to the motor.
For belt drive units in continuous high temperature installations, the electrical supply must be kept out of the
airstream. This means bringing the supply lines off the roof deck not through the fan. The electrical supply line should
then be either: (1) connected to an optional service disconnect switch, or (2) wired directly to the motor.
The supply wires are then connected to an optional safety disconnect switch (if supplied) or wired directly to the
motor.
For belt drive units in emergency smoke removal installations, the electrical supply must be kept out of the
airstream. They may also require an isolated power supply so that if power is cut to the building in the event of a fire,
the fan will continue to operate. Check the local and national electrical codes for emergency smoke removal fans.
Pre-Start-Up Checks
1. Check all fasteners for tightness. This includes motor bolts, bearing bolts, and any set screws or locking collars
attaching the propeller to the shaft and shaft to the bearings.
If roof upblast configuration, lift the butterfly dampers to verify they open and close without binding.
2. Rotate the propeller by hand to ensure it turns freely and does not rub on the fan tube.
Propeller rotation should always be checked by turning the unit on momentarily. Rotation
should be in the same direction as the rotation decal affixed to the unit. Actual direction
of rotation will vary by model. To reverse rotation on three phase installations, simply
interchange two of the three electrical leads. For single phase installations, follow the wiring
diagram located on the motor.
3. Belt Drive Fan RPM - adjustable motor pulleys are preset at the factory for the specified
fan RPM. Fan speed can be increased by closing or decreased by opening the adjustable pulley. Multi-groove
variable pitch pulleys must be adjusted an equal number of turns open or closed.
4. Belt Drive Roof Upblast Fan RPM - adjustable motor pulley on motors less than 10 HP is preset at the factory
to the customer-specified RPM. Fan speed can be increased or decreased by adjusting the pitch diameter of the
motor pulley. Multi-groove variable pitch pulleys must be adjusted an equal number of turns open. Motors 10 hp
and larger will have a constant speed pulley.
Any change, increase or decrease, in fan speed can represent a substantial increase in horsepower required from
the motor. Always check motor load amperage and compare to nameplate rating when changing fan speed.
®
NOTE
Rotation
Tubular Inline Fans
7
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