Modine Manufacturing 6-558.6 - Manual (Page 9)

INSTALLATION
9
without filters operating with one external static pressure, that
is, no duct work, nozzles, etc., and is to deliver an air flow of
2071 cfm (cfm = cubic feet of air) requires that the unit be
supplied with a 1/2 hp motor, a C25 drive and, the motor
sheave set at 5 turns open to achieve a blower speed of 255
rpm (see performance table for units without blower enclosure,
page 14). See “Blower Adjustments” for setting of motor sheave
turns open.
If a blower unit is to be used with ductwork or nozzles, etc., the
total external static pressure under which the unit is to operate,
and the required air flow must be known before the unit can be
properly adjusted. Any device added externally to the unit, and
which the air must pass through, causes a resistance to air
flow. This resistance is called pressure loss. The total of the
pressure losses must be determined before adjusting the
blower speed.
If Modine filters are used, the expected pressure loss through
the filters is included in performance data on page 15. If Modine
supplied discharge nozzles are used, the expected pressure
loss of the nozzles can be found footnoted at the bottom of
page 10. If filters, nozzles, or ductwork are to be used with the
unit, and they are not supplied by Modine, the design engineer
or installing contractor must determine the pressure loss for the
externally added devices, or ductwork, to arrive at the total
external static pressure under which the unit is to operate.
Once the total external static pressure and the required air flow
are known, the operating speed of the blower can be
determined and the correct motor sheave adjustments made.
As an example, let’s say a model BSH150 is to be used with a
Modine supplied blower enclosure, Modine supplied filters, are
to be attached to ductwork supplied by others, and the unit is to
move 2071 cfm of air flow against an external static pressure of
0.2" W.C. static pressure, it is seen that the unit will require a
1/2 hp motor using a C22 drive, and the motor sheave should
be set at 1 turn open to achieve a blower speed of 415 rpm.
See “Blower Adjustments” for setting of motor sheave turns
open.
To Install (Figure 8):
1. Remove and discard the tie down strap and the shipping
block beneath the belt tension adjusting screw. (Not used
on all models.)
2. Adjust belt tension adjusting screw for a belt deflection of
approximately 3/4" with five pounds of force applied midway
between the sheaves (refer to Figure 9a). Since the belt
tension will decrease dramatically after an initial run-in
period, It is necessary to periodically re-check the tension.
excessive tension will cause bearing wear and noise.
3. The blower bearings are lubricated for life; however, before
initial unit operation the blower shaft should be lubricated at
the bearings with SAE20 oil. This will reduce initial friction
and start the plastic lubricant flowing.
4. Make electrical connections according to the wiring
diagram.
5. Check rotation of the blower. Motor should be in clockwise
rotation when facing motor pulley. If rotation is incorrect,
correction should be made by interchanging wiring within
the motor. See wiring diagram on the motor.
6. The actual current draw of the motor should be determined.
Under no condition should the current draw exceed that
shown on the motor rating plate.
7. It is the installer’s responsibility to adjust the motor sheave to
provide the specified blower performance as listed on pages
14 and 15, for blower settings different
Recommended Installations Dimension “B” Should Never
Be Less than 1/2 of “A”
A
3" MIN.
12"
MIN.
3" MAX.
TURNING
VANES
12"
B
BAFFLE
12"
MIN.
A
B
BAFFLE
TURNING
VANES
A
BAFFLE
B
12" MIN.
B
3" MAX.
TURNING
VANES
3" MIN.
A
A
B
12"
MIN.
12"
MIN.
TURNING
VANES
SIDE VIEW SIDE VIEW TOP VIEW
SIDE VIEW SIDE VIEW TOP VIEW
D E F
A B C
Figure 8
Blower Model Installation
Threaded Rod
Mounting Brackets on
Blower Assembly
Motor Mounting
Bracket
Motor Sheave
(Movable Face
to Outside)
Motor
Adjustment
Screw
Blower Housing Combustion Air Inlet
Blower
Sheave
Heater Parts from ACF Greenhouses