Cooling Sequence Of Operation; Maintenance; Air Filter; Indoor Blower And Motor - Bryant LEGACY PURON 704D Series Installation Instructions Manual

COOLING SEQUENCE OF OPERATION

With the room thermostat SYSTEM switch in the COOL position
and the FAN switch in the AUTO position, the cooling sequence of
operation is as follows:
When the room temperature rises to a point that is slightly above
the cooling control setting of the thermostat, the thermostat
completes the circuit between thermostat terminal R to terminals Y
and G. These completed circuits through the thermostat connect
contactor coil (C) (through unit wire Y) and time delay relay
(TDR) (through unit wire G) across the 24- -V secondary of
transformer (TRAN).
The normally open contacts of energized contactor (C) close and
complete the circuit through compressor motor (COMP) to
condenser (outdoor) fan motor (OFM). Both motors start instantly.
The set of normally open contacts of energized relay TDR close
and complete the circuit through evaporator blower (indoor) fan
motor (IFM).
NOTE: Once the compressor has started and then has stopped, it
should not be started again until 5 minutes have elapsed.
The cooling cycle remains on until the room temperature drops to a
point that is slightly below the cooling control setting of the room
thermostat. At this point, the thermostat breaks the circuit between
thermostat terminal R to terminals Y and G. These open circuits
deenergize contactor coil C and relay coil TDR. The condenser and
compressor motors stop. After a 60- -second delay, the blower
motor stops. The unit is in a standby condition, waiting for the next
call for cooling from the room thermostat.

MAINTENANCE

To ensure continuing high performance, and to minimize the
possibility of premature equipment failure, periodic maintenance
must be performed on this equipment. This cooling unit should be
inspected at least once each year by a qualified service person. To
troubleshoot unit, refer to Table 7, Troubleshooting Chart.
NOTE TO EQUIPMENT OWNER: Consult your local dealer
about the availability of a maintenance contract.
WARNING
!
PERSONAL INJURY
HAZARD
Failure to follow this warning could result in personal
injury or death and possible unit component damage.
The ability to properly perform maintenance on this
equipment requires certain expertise, mechanical skills,
tools and equipment. If you do not possess these, do not
attempt to perform any maintenance on this equipment,
other than those procedures recommended in the Owner's
Manual.
WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow these warnings could result in personal
injury or death:
1. Turn off electrical power to the unit and install lockout
tag before performing any maintenance or service on this
unit.
2. Use extreme caution when removing panels and parts.
3. Never place anything combustible either on or in contact
with the unit.
AND UNIT DAMAGE
CAUTION
!
UNIT OPERATION HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
Errors made when reconnecting wires may cause improper
and dangerous operation. Label all wires prior to
disconnecting when servicing.
The minimum maintenance requirements for this equipment are as
follows:
1. Inspect air filter(s) each month. Clean or replace when
necessary.
2. Inspect indoor coil, drain pan, and condensate drain each
cooling season for cleanliness. Clean when necessary.
3. Inspect blower motor and wheel for cleanliness each
cooling season. Clean when necessary.
4. Check electrical connections for tightness and controls for
proper operation each cooling season. Service when
necessary.
5. Ensure electric wires are not in contact with refrigerant
tubing or sharp metal edges.

AIR FILTER

IMPORTANT: Never operate the unit without a suitable air filter
in the return- -air duct system. Always replace the filter with the
same dimensional size and type as originally installed. See Table 1
for recommended filter sizes.
Inspect air filter(s) at least once each month and replace
(throwaway- -type) or clean (cleanable- -type) at least twice during
each cooling season and twice during the heating season, or
whenever the filter becomes clogged with dust and lint.

INDOOR BLOWER AND MOTOR

NOTE: All motors are pre- -lubricated. Do not attempt to lubricate
these motors.
For longer life, operating economy, and continuing efficiency,
clean accumulated dirt and grease from the blower wheel and
motor annually.
WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Disconnect and tag electrical power to the unit before
cleaning the blower motor and wheel.
To clean the blower motor and wheel:
1. Remove and disassemble blower assembly as follows:
a. Remove unit access panel.
b. Disconnect 5 pin plug and 4 pin plug from indoor
blower motor.
c. On all units remove blower assembly from unit.
Remove screws securing blower to blower partition and
slide assembly out. Be careful not to tear insulation in
blower compartment.
d. Ensure proper reassembly by marking blower wheel and
motor in relation to blower housing before disassembly.
e. Loosen setscrew(s) that secures wheel to motor shaft,
remove screws that secure motor mount brackets to
housing, and slide motor and motor mount out of
housing.
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