Greenheck Fan Model CWB Pre-Starting Belt Tension Checks, Operation CW/CWB, Belts, Fasteners

WARNING

Correct direction of wheel rotation is critical. Reversed rotation will result in poor air performance, motor overloading and possible burnout.

Model CWB

Pre-Starting Belt Tension Checks

8.Always loosen tension enough to install belts without stretching, see figure 9.

Belts

	Do not force belt(s). Forcing the
Figure 9	belt(s) will break the cords and
	cause belt failure

9.For units with two groove pulleys, adjust so the tension is equal in both belts.

10.If adjustments are made, it is very important to check the pulleys for proper alignment. Misaligned pulleys lead to excessive belt wear vibration, noise and power loss, see figure 10.

Figure 10

11.For CWB units: Belt tension can be adjusted by loosening four fasteners on the drive frame, see figure 11. The motor plate slides on the slotted adjusting arms and drive frame angles in the same manner.

Fasteners

(4) *Fasteners

*Identical fasteners on opposing side must also be loosened.

Figure 11

12a. Sizes 071-161: Belts should be tensioned just enough to prevent slippage at full load. Belts should have a slight bow on the slack side while running at full load (see figure 12a).

12b. Sizes 180-540: Belt tension should be adjusted to allow 1/64 in. (0.397 mm) of deflection per inch of belt span. For example, a 15 in. (381 mm) belt span

®

WARNING

The fan has been checked for mechanical noises at the factory prior to shipment. If mechanical noise should develop, suggested corrective actions are offered in the Troubleshooting section.

IMPORTANT

Over tightening will cause excessive bearing wear and noise. Too little tension will cause slippage at startup and uneven wear.

should have 15/64 in. (0.234 mm) (or about 1/4 in. (6 mm)) of deflection with moderate thumb pressure at mid-point between pulleys (see figure 12b).

Deflection

Slack

Side

Figure 12a Figure 12b

13.The adjustable motor pulley is factory set for the RPM specified. Speed can be increased by closing or decreased by opening the adjustable motor pulley. Two groove variable pitch pulleys must be adjusted an equal number of turns open or closed.

14.Any increase in speed represents a substantial increase in the horsepower required by the unit.

15.Motor amperage should always be checked to avoid serious damage to the motor when speed is varied.

Operation: CW/CWB

1.Before starting up or operating fan, check all fasteners for tightness. In particular, check the setscrews in wheel hub (and pulleys, if applicable).

2.While in the OFF position or before connecting the fan to power, turn the fan wheel by hand to be sure it is not striking the venturi or any obstacle.

3.Start the fan and shut it off immediately to check rotation of the wheel with directional arrow in the motor compartment, see figure 8.

4.When the fan is started, observe the operation and check for any unusual noises.

5.With the system in full operation and all ductwork attached, measure current input to the motor and compare with the nameplate rating to determine if the motor is operating under safe load conditions.

6.Keep inlets and approaches to fan clean and free from obstruction.

Model CW/CWB • Centrifugal Sidewall Exhaust Fans 5