Carrier P - Manual (Page 23)

23
SEQUENCE OF OPERATION
■ HEAT/COOL UNITS (Figure 43)
Fan Mode — With the selector switch set to FAN con-
tacts L1 to HI and FCS1 to LS are made.
Cooling (Low) — With the selector switch set to low
speed cooling contacts FCS2 to LO, COMP to FCS1,
and COMP to IT3 are made.
Cooling (High) — With the selector switch set to high
speed cool contacts FCS2 to HI, COMP to FCS1, and
COMP to IT3 are made.
Heating (Low) — With the selector switch set to low
speed heat contacts FCS2 to LO, IT1 to LS, L2 to HTR,
and FCS1 to LS are made.
Heating (High) — With the selector switch set to high
speed heat contacts FCS2 to HI, IT1 to LS, L2 to HTR,
and FCS1 to LS are made.
FIGURE 43 — SELECTOR SWITCH CONTACTS,
ALL 52CE, PE ELECTRIC HEAT/COOL UNITS
■ COOLING ONLY UNITS (Figure 44)
Fan Mode — With the selector switch set to FAN con-
tact L1 to LO is made.
Cooling (Low) — With the selector switch set to low
speed cooling contacts FCS to LO and L1 to IT3 are
made.
Cooling (High) — With the selector switch set to high
speed cool contacts FCS to HI, L1 to IT3 are made.
FIGURE 44 — SELECTOR SWITCH CONTACTS,
ALL 52CE, PE COOLING ONLY UNITS
■ HEAT PUMP UNITS (Figure 45)
Fan Mode — With the selector switch set to fan contact
L1 to HI is made.
Cooling (Low) — With the selector switch set to low
cool contacts L1 to IT3 and FCS to LO are made.
Cooling (High) — With the selector switch set to high
cool, contacts L1 to IT3 and FCS to HI are made.
Heating (Low) — With the selector switch set to low
heat contacts L1 to IT1, FCS to LO and L2 to HTR are
made.
Heating (High) — With the selector switch set to high
heat contacts L1 to IT1, FCS to HI, and L2 to HTR are
made.
Defrost Cycle — When heat pump unit is operating in
reverse cycle, the outdoor coil may begin to frost. As
frost accumulates on the outdoor coil the unit may
switch into defrost mode. The defrost mode is activated
when the outdoor frost thermostat sensor detects a
temperature below 20 F on the coil. At this point, the
thermostat deenergizes the compressor and activates
the electric heat. The unit will remain in electric heat
mode until the outdoor thermostat senses 35 F coil
temperature. The defrost mode is a passive operation
and may take some time before the coil defrosts.
FIGURE 45 — SELECTOR SWITCH CONTACT,
ALL 52CQ, PQ HEAT PUMP UNITS
COMPONENT OPERATION AND
TROUBLESHOOTING
■ TOOLS NEEDED
SWITCH
POSITION
CONTACTS MADE
OFF NONE
FAN L1 TO HI, FCS1 TO LS
LO HEAT FCS2 TO LO, IT1 TO LS, L2 TO HTR, FCS1 TO LS
HI HEAT FCS2 TO HI, IT1 TO LS, L2 TO HTR, FCS1 TO LS
LO COOL FCS2 TO LO, COMP TO FCS1, COMP TO IT3
HI COOL FCS2 TO HI, COMP TO FCS1, COMP TO IT3
SWITCH
POSITION
CONTACTS MADE
OFF NONE
FAN LO L1 TO LO
FAN HI L1 TO HI
LO COOL L1 TO IT3, FCS TO LO
HI COOL L1 TO IT3, FCS TO HI
SWITCH
POSITION
CONTACTS MADE
OFF NONE
FAN L1 TO HI
LO HEAT L1 TO IT1, FCS TO LO, L2 TO HTR
HI HEAT L1 TO IT1, FCS TO HI, L2 TO HTR
LO COOL L1 TO IT3, FCS TO LO
HI COOL L1 TO IT3, FCS TO HI
Volt-Ohmmeter
Flat and Phillips Screw Drivers
5 /
16
-in. Nut Driver
Side Cutting Pliers
Before cleaning, servicing, performing maintenance
or removing the chassis from the wall sleeve, discon-
nect all power to the unit to avoid the possibility of
electrical shock and personal injury. Only trained
and qualified service personnel should perform
installation and service procedures on these units.
Untrained personnel may perform basic mainte-
nance tasks such as cleaning and replacing filters.
Refer to UNIT DISASSEMBLY section of this man-
ual for proper procedures to disconnect power to
52C,P units.