Carrier COMFORT 50EZ-A30, Installation Instructions Manual

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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 10.
NOTE : TO EQUIPMENT OWNER: Consult your local dealer
about the availability of a maintenance contract.
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.
!
WARNING
CUT HAZARD
Failure to follow this caution may result in personal injury.
When removing access panels (see Fig. 19.) 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.
CAUTION
!
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.
50E
Z
--
A