Step 3 — Defrost Control
Quiet Shift
Quiet Shift is a field-selectable defrost mode, which will eliminate occasional noise that could be heard at the start of defrost cycle and restarting of heating cycle. It is selected by placing DIP switch 3 (on defrost board) in ON position.
When Quiet Shift switch is placed in ON position, and a defrost is initiated, the following sequence of operation will occur. Reversing valve will energize, outdoor fan will turn off, compressor will turn off for 30 sec and then turn back on to complete defrost. At the start of heating after conclusion of defrost reversing valve will de-energize, compressor will turn off for another 30 sec, and the outdoor fan will stay off for 40 sec, before starting in the Heating mode.
Defrost
The defrost control is a time/temperature control which includes a field-selectable time period (DIP switch 1 and 2 on the board) between defrost cycles of 30, 60, 90, or 120 minutes (factory set at 60 minutes). To initiate a forced defrost, two options are available depending on the status of the defrost thermostat.
If defrost thermostat is closed, speed-up pins (J1) must be shorted by placing a flat head screw driver in between for 5 sec and releasing, to observe a complete defrost cycle. When the Quiet Shift switch is selected, compressor will be turned off for two 30 sec intervals during this complete defrost cycle, as explained previously. When Quiet Shift switch is in factory default OFF position, a normal and complete defrost cycle will be observed.
If defrost thermostat is in open position, and speedup pins are shorted (with a flat head screw driver) for 5 sec and released, a short defrost cycle will be observed (actual length is dependent upon the selected Quiet Shift position). When Quiet Shift switch is in ON position, the length of defrost is 1 minute (30 sec compressor off period followed by 30 sec of defrost with compressor operation). On return to heating operation, compressor will again turn off for an additional 30 sec and the outdoor fan for 40 sec. When the Quiet Shift is in OFF position, only a brief 30 sec. cycle will be observed.
NOTE: Unit will remain in defrost until defrost thermostat reopens at approximately 65_F (18_C) coil temperature at liquid line or remainder of defrost cycle time.
MAINTENANCE
To ensure continuing high performance, and to minimize the possibility of premature equipment failure, periodic maintenance must be performed on this equipment. This heat pump unit should be inspected at least once each year by a qualified service person. To troubleshoot unit, refer to Table 9.
NOTE: TO EQUIPMENT OWNER: Consult your local dealer about the availability of a maintenance contract.
!WARNING
PERSONAL INJURY AND UNIT DAMAGE HAZARD
Failure to follow this warning could result in personal injury or death and 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 a 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.
!CAUTION
CUT HAZARD
Failure to follow this caution may result in personal injury.
When removing access panels (see Fig. 20) or performing maintenance functions inside your unit, be aware of sharp sheet metal parts and screws. Although special care is taken to reduce sharp edges to a minimum, be extremely careful when handling parts or reaching into the unit.
!CAUTION
UNIT OPERATION HAZARD
Failure to follow this caution may result in 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.
Step 1 — 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.
NOTE: 460 volt units have a stepdown autotransformer that supplies approximately 230 volts to a nominal 230 volt indoor blower motor.
For longer life, operating economy, and continuing efficiency, clean accumulated dirt and grease from the blower wheel and motor annually.
