Sequence Of Operation; Comfort Control Call For Heat - Trane *UH2B060A9V3VA Service Facts

The following warning complies with State of California law, Proposition 65.
▲
WARNING
!
This product contains fiberglass wool insulation!
Fiberglass dust and ceramic fibers are believed by the
State of California to cause cancer through inhalation.
Glasswool fibers may also cause respiratory, skin, or
eye irritation.
PRECAUTIONARY MEASURES
●
Avoid breathing fiberglass dust.
●
Use a NIOSH approved dust/mist respirator.
●
Avoid contact with the skin or eyes. Wear long-sleeved,
loose-fitting clothing, gloves, and eye protection.
●
Wash clothes separately from other clothing: rinse
washer thoroughly.
● Operations such as sawing, blowing, tear-out, and
spraying may generate fiber concentrations requiring
additional respiratory protection. Use the appropriate
NIOSH approved respirator in these situations.
FIRST AID MEASURES
Eye Contact – Flush eyes with water to remove dust.
If symptoms persist, seek medical
attention.
Skin Contact – Wash affected areas gently with soap
and warm water after handling.
▲
WARNING
!
EXPLOSION HAZARD
SHOULD OVERHEATING OCCUR, OR THE GAS SUPPLY
FAIL TO SHUT OFF, SHUT OFF THE GAS VALVE TO THE UNIT
BEFORE SHUTTING OFF THE ELECTRICAL SUPPLY.
FAILURE TO FOLLOW THIS WARNING COULD RESULT IN
PROPERTY DAMAGE, PERSONAL INJURY, OR DEATH
▲
WARNING
!
BURN HAZARD
DO NOT TOUCH IGNITER. IT IS EXTREMELY HOT. FAILURE
TO FOLLOW THIS WARNING COULD RESULT IN SEVERE
BURNS.
▲
WARNING
!
RISK OF ELECTRIC SHOCK:
THESE SERVICING INSTRUCTIONS ARE FOR USE BY
QUALIFIED PERSONNEL ONLY. TO REDUCE THE RISK
OF ELECTRIC SHOCK, DO NOT PERFORM ANY SERVIC-
ING OTHER THAN THAT CONTAINED IN THESE OPERAT-
ING INSTRUCTIONS UNLESS YOU ARE QUALIFIED TO
DO SO. FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN PROPERTY DAMAGE, PERSONAL INJURY OR
DEATH.
▲
CAUTION
!
The integrated furnace control is polarity sensitive. The hot
leg of the 115 VAC power must be connected to the BLACK
field lead.
X343070P08
Service Facts
▲
CAUTION
!
Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and dangerous
operation. Verify proper operation after servicing.
▲
CAUTION
!
Do NOT touch igniter. It is extremely hot.

SEQUENCE OF OPERATION

▲
WARNING
!
EXPLOSION HAZARD
SHOULD OVERHEATING OCCUR, OR THE GAS SUPPLY
FAIL TO SHUT OFF, SHUT OFF THE GAS VALVE TO THE UNIT
BEFORE SHUTTING OFF THE ELECTRICAL SUPPLY.
FAILURE TO FOLLOW THIS WARNING COULD RESULT IN
PROPERTY DAMAGE, PERSONAL INJURY, OR DEATH
▲
WARNING
!
SAFETY HAZARD
BODILY INJURY CAN RESULT FROM HIGH VOLTAGE
ELECTRICAL COMPONENTS, FAST MOVING FANS,
AND COMBUSTIBLE GAS. FOR PROTECTION FROM
THESE INHERENT HAZARDS DURING INSTALLATION
AND SERVICING, THE ELECTRICAL SUPPLY MUST
BE DISCONNECTED AND THE MAIN GAS VALVE
MUST BE TURNED OFF. IF OPERATING CHECKS
MUST BE PERFORMED WITH THE UNIT OPERATING,
IT IS THE TECHNICIANS RESPONSIBILITY TO
RECOGNIZE THESE HAZARDS AND PROCEED
SAFELY.
COMFORT CONTROL CALL FOR HEAT (2-STAGE COMFORT
CONTROL)
Call for 1st Stage only:
W1 Comfort Control contacts close signaling the control
module to run its self-check routine. After the control module
has verified that the 1st Stage Pressure Switch contacts are
open and the Limit Switch(es) contacts are closed, the draft
blower will be energized.
As the induced draft blower comes up to speed, the Pressure
Switch contacts will close and the ignitor warm up period will
begin. The ignitor will heat for approx. 20 seconds, then the
Gas Valve is energized in 1st Stage to permit gas flow to the
burners.
The flame sensor confirms that ignition has been achieved
within the 4 second ignition trial period.
As the flame sensor confirms that ignition has been achieved,
the delay to fan ON period begins timing and after approx. 45
seconds the indoor blower motor will be energized at low
speed and will continue to run during the heating cycle.
Call for 2nd Stage after 1st Stage:
W2 Comfort Control contacts close signaling a call for 2nd
Stage Heat. After a 30 second delay, the induced draft blower
will be energized on high speed and the 2nd Stage Pressure
Switch contacts will close. The Gas Valve is energized in 2nd
Stage and the indoor blower motor in high speed.
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