Sterling QVEB - Manual (Page 9)

9
INSTALLATION
(continued)
Never operate the unit beyond
the specified limits or severe damage to, and or
premature failure of, the unit will result!
BLOWER SET UP
The drive ratio of the motor and blower sheaves has
been preset at the factory for a temperature rise of 65°F
at 0 inch W.C. If the unit is to be operated under different
air fl ow or pressure requirements, the drive ratio must
be altered by means of the adjustable sheave on the
blower motor, Figure 7.
1. Ensure that all packing material, support blocks, etc.
have been removed from the unit.
2. Adjust the blower drive belt tension by means of the
two tension bolts on the blower motor base. When
proper tension has been achieved, the mid-point
defl ection of the belt will be 3/4 inch when subjected
to a 5 lb. force.
3. Recheck all electrical connections.
4. When power is applied, ensure that the motor and
blower are rotating in a clockwise direction when
viewed from the drive side.
5. Measure the current draw of the motor.
The "at speed" current draw of the
motor must never exceed that specified on the
motor rating plate or severe damage to the motor
will result!
* NOTICE: THE BLOWER ASSEMBLY FOR THE 100/250 UNITS
CONSISTS OF 1 WHEEL, 1 HOUSING, 1 SHAFT AND 1 BEARING
SET. FOR 300/400 UNITS THE BLOWER ASSEMBLY CONSISTS OF
2 WHEELS, 2 HOUSINGS, 1 SHAFT AND 1 BEARING SET.
Figure 7 - Motor & Blower Assembly *
* PART DESCRIPTION
A. Blower Housing
B. Blower Wheel
C. Blower Shaft
D. Bearings (sets only)
E. Drive Pulley (standard)
F. Driven Pulley (standard)
G. V-Belt
H. Motor
BLOWER DRIVE ADJUSTMENT
Never attempt to adjust the drive
belt without fi rst disconnecting all electrical
power to the unit or severe personal injury may
result!
1. Remove the belt guard and loosen the belt tension
bolts on the blower motor base.
2. Loosen the set screw on the adjustable half of the
motor sheave. To increase the blower speed, turn
the adjustable half of the sheave clockwise, counter
clockwise to slow the blower. Retighten the set
screw.
3. Realign the blower and motor sheaves if necessary.
4. Adjust the belt tension as specifi ed in the BLOWER
SET UP section under step 2.
5. Replace the belt guard.
Never operate the unit without
the belt guard in place or severe personal injury
may result!
6. Check that the air flow of the unit, the r pm
and current draw of the blower motor and the
temperature rise are within the limits specified in
Table 1, the blower motor rating plate and the rating
plate on the unit, respectively (also see Motor Data
on page 10).