28141 Rev A 10-27-06
8
may correct this problem; however, a belt drive
blower system is the better solution, since motor
RPM and CFM delivery is not particularly
influenced by system external static pressure.
Direct drive blower speeds are adjusted by
changing the "hot" wires to the motor winding
connections. Please refer to wiring diagrams in
Appendix B or the wiring diagram label affixed to
the furnace.
THE NEUTRAL WIRE (normally the
white wire) IS NEVER MOVED TO ADJUST
THE BLOWER SPEED
.
It is possible and acceptable to use a single
blower speed for both heating and cooling modes.
The simplest method to connect the wiring from
both modes is to use a "piggy-back connector"
accommodating both wires on a single motor tap.
It is also acceptable to connect the selected motor
speed with a pig tail joined to both heating and
cooling speed wires with a wire nut. As a safety
precaution against accidental disconnection of the
wires by vibration, it is advisable to secure the
wire nut and wires with a few wraps of electricians
tape.
DO NOT CONNECT POWER LEADS
BETWEEN MOTOR SPEEDS. THE
NEUTRAL WIRE MUST ALWAYS BE
CONNECTED TO THE MOTOR'S
DESIGNATED NEUTRAL TERMINAL.
DISCONNECT THE POWER SUPPLY TO
THE FURNACE BEFORE OPENING THE
BLOWER ACCESS DOOR TO SERVICE
THE AIR FILTER, FAN AND MOTOR.
FAILURE TO SHUT OFF POWER COULD
ALLOW THE BLOWER TO START
UNEXPECTEDLY, CREATING A RISK OF
DEATH OR PERSONAL INJURY.
If the joining of the blower speed wiring is done in
the furnace junction box, tape off both ends of the
unused wire.
Do not use the blower speed wires as a source
of power to accessories as electronic air
cleaners and humidifier transformers unless it
is certain that only one motor speed will be
used
. The unused motor taps auto-generate
sufficiently high voltages to damage accessory
equipment.
Belt drive blower systems can be modified for a
variety of speeds and air delivery by adjusting the
variable speed motor pulley, and by changing the
blower pulley.
The variable speed motor pulley may be adjusted
by loosening the 5/32 Allen set screw in the outer
sheave, and turning the outer sheave clockwise to
increase blower speed; counter clockwise to
reduce blower speed. Ensure that the setscrew is
tightened at one of the "flat spots", failure to do so
will convert the variable speed pulley to a fixed
speed pulley by ruining the threads. The blower
speed can be modified by the changing of the
blower pulley. A smaller blower pulley will cause
the blower to turn faster; a larger pulley will
reduce blower speed. Large increases in blower
speed may increase power requirements. Check
the amperage draw of the blower motor after
changes have been made. If the amperage draw
is greater than the value listed on the motor rating
plate, replace with a motor of higher horsepower.
The fan belt tension is very important. There
should be a deflection of ¾ of an inch to 1 inch.
Less deflection places a strain on the blower
bearings, and increases start up amperage draw.
More deflection allows excess slippage and
causes premature motor pulley wear. Automotive
belt dressings are not recommended. A hard soap
such as Sunlight
®
soap will work well as a belt
dressing, for the purpose of reducing belt
squeaks, etc. If used, the soap should be applied
to the sides of the belt only.
THE BELT DRIVE COMPONENTS OPERATE
AT HIGH SPEEDS AND CAN EASILY SNAG
LOOSE CLOTHING, CAUSING SERIOUS
PERSONAL INJURY. THIS PROCEDURE
SHOULD BE LEFT TO TRAINED SERVICE
PERSONNEL.
If planning to operate the belt drive blower at
speeds above 1100 RPM, it is advisable to
Summary of Contents for BCL
Page 23: ...28141 Rev A 10 27 06 23 TABLE B 1 BECKETT AND RIELLO CHIMNEY VENTED WIRING DIAGRAM BCL S BFL ...
Page 24: ...28141 Rev A 10 27 06 24 TABLE B 2 BECKETT AND RIELLO DIRECT VENT WIRING DIAGRAM BCL S BFL ...
Page 29: ...29809 Rev A 10 19 2006 29 ...
Page 32: ...29809 Rev A 10 19 2006 32 ...
Page 36: ...29809 Rev A 10 19 2006 36 ...
Page 41: ...28141 Rev A 10 27 06 NOTES ...
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