BEFORE OPERATING THE FURNACE CHECK
BURNER ALIGNMENT WITH COMBUSTION
CHAMBER. THE END CONE OF THE AIR TUBE
MUST BE CENTRED TO THE ACCOMODATING
RING PROVIDED IN THE DESIGN OF
THE
COMBUSTION
CHAMBER. ADJUST AS
NECESSARY.
16. BURNER ELECTRODES
Correct positioning of the electrode tips with respect to
each other, to the fuel oil nozzle, and to the rest of the
burners is essential for smooth light ups and proper
operation. Refer to the oil burner instructions shipped
with the furnace for electrode specifications.
NOTE: Beckett AF Series Burner electrode specifications
have been revised. They should be adjusted to be 5/16”
above the nozzle centerline.
17. BURNER PRIMARY (SAFETY) CONTROL
The furnace is equipped with a primary combustion
control, sometimes referred to as the burner relay or
burner protector relay, which uses a light sensing device
(cad cell) located in the burner housing, to monitor and
control combustion. Over time, dust or combustion
residuals can build up on the lens of the cad cell
impairing its response to the flame. The cad cell should
be checked for cleanliness and proper alignment if the
primary control frequently shuts down combustion.
ALL FURNACE CONTROLS ARE
SENSITIVE
AND SHOULD NOT BE SUBJECTED TO
TAMPERING. IF PROBLEMS PERSIST, CALL
YOUR SERVICE CONTRACTOR.
18. COMBUSTION CHAMBER
This furnace is equipped with a high quality cerafelt
combustion chamber. It is held in place by a retaining
bracket.
CHECK THE ALIGNMENT OF THE COMBUSTION
CHAMBER AND OIL BURNER BEFORE FIRING.
IT IS POSSIBLE FOR THE
COMBUSTION
CHAMBER TO SHIFT IF SUBJECTED TO ROUGH
HANDLING DURING TRANSIT
.
The combustion
chamber should be inspected for damage or carbon build
up whenever the oil burner is removed for repairs or
routine maintenance.
DO NOT START THE BURNER UNLESS THE
BLOWER ACCESS DOOR IS SECURED IN
PLACE.
19a. CIRCULATING AIR BLOWER (O4HD-
091A-12-FB)
The O4HD-091A-12-FB, O4HD-091A-14-FA-DV and
O4HD-091A-V-FA furnace models are equipped
with direct drive blower systems. O4HD-091A-12-
FB and O4HD-091A-14-FA-DV models are
equipped with PSC motors; O4HD-091A-V-FA
models are equipped with electronically commutated
motors (ECM). Direct drive blower speed
adjustments are not normally required in properly
sized extended plenum duct systems. The motor
RPM and air CFM delivery will vary automatically to
accommodate conditions within the usual range of
external static pressures typical of residential duct
systems. Under-sized duct systems may require a
higher blower speed to obtain a reasonable system
temperature rise. Some older duct systems were not
designed to provide static pressure. They typically
feature special reducing fittings at each branch run
and lack block ends on the trunk ducts. These
systems may require modification to provide some
resistance to the airflow to prevent over-amping of
the direct drive blower motor. Selecting a lower
blower speed may correct this problem. 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 w hite w ire) 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 pigtail 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.
7
Summary of Contents for O4HD-091A-12-FB
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