300 SERIES
ROOF EXHAUST
MOTOR, PULLEYS & BELTS
(See Table below)
1.
Mount the blower sheave on the blower shaft and tighten its set screw securely on the key of the shaft,
(See Table 1
for Drive Data)
2.
Mount the motor sheave on the motor shaft. Leave some clearance between the pulley and the motor end bell. Tighten the set screws
on the key of the motor shaft.
3.
Slide the square head bolts into the channel provided in the motor bracket. Place the motor into position, finger tighten the nuts to
temporarily secure the motor. Attach the motor adjustment (belt tension) assembly.
4.
With the motor adjusting bolt in its minimum positon install the V belt within the sheave grooves. Slide the motor within the motor
bracket to ensure proper pulley alignment
(see Figure 2).
A straight edge across the face of the driven pulley should be parallel to
the belt once proper alignment has been achieved. Tighten the nuts on the motor base to anchor the motor position within the bracket.
5. NOTE:
Pulley alignment may change when adjusting variable pitch pulleys.
Adjust belt tension by turning the motor adjustment hook
bolt. Ideal belt tension is the lowest tension at which the belt will not slip during start up.A rule of thumb suggests that 3/4” of deflection
mid span under medium finger pressure (2-3 lbs.) for every foot of span is approximately proper belt tension. Lock the motor adjustment
(belt tension) assembly once proper belt tension has been achieved.
WARNING
EXCESSIVE BELT TENSION IS THE MOST FREQUENT CAUSE OF BEARING WEAR
AND RESULTING NOISE. PROPER BELT TENSION IS CRITICAL FOR QUIET
EFFICIENT OPERATION.
Ideal belt tension is the lowest value under which belt slip will not occur at peak load conditions.
300 SERIES_03_11_22
Page 2 of 4
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Table 1: Drive Table
