Controls - Carrier 50HX024-060 Product Data

Performance data (cont)
ACCESSORY ELECTRIC HEATER PRESSURE DROP (in. wg)
HEATER
kW
600 800
5-20 0.030 0.033
UNIT FILTER
SIZE SIZE
500 600 700
50HX (in.)
024,030 24 x 24 — —
036-060 24 x 30 — —
MINIMUM AIRFLOW (CFM) FOR SAFE ELECTRIC HEATER OPERATION
024 030
800 1000

Controls

Sequence of operation
When power is supplied to unit, the transformer (TRAN) is
energized.
Cooling — With the thermostat subbase in the cooling
position, and when the space temperature comes within
2° F of the cooling set point, the thermostat makes circuit
R-O. This energizes the reversing valve solenoid (RVS) and
places the unit in standby condition for cooling.
As the space temperature continues to rise, the second
stage of the thermostat makes, closing circuit R-Y. When
compressor time delay (5 ± 2 minutes) is completed, a cir-
cuit is made to contactor (C), starting the compressor (COMP)
and outdoor-fan motor (OFM). Circuit R-G is made at the
same time, starting the indoor-fan motor (IFM) after a 1-second
delay.
When the thermostat is satisfied, contacts open, deener-
gizing C. The COMP and OFM stop, and the IFM stops
after a short time delay.
18
CFM
1000 1200 1400
0.037 0.042 0.047
FILTER PRESSURE DROP (in. wg)
800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300
0.06 0.06 0.07 0.07 0.08
— — — 0.07 0.07
UNIT SIZE
50HX
036 042
1225 1300
1600 1800 2000 2200
0.052 0.060 0.067 0.075
CFM
0.09 — — — —
0.08 0.08 0.09 0.09 0.10
048 060
1600 1750
Heating — On a call for heat, thermostat makes circuits
R-Y and R-G. When compressor time delay (5 ± 2 minutes)
is completed, a circuit is made to C, starting COMP and
OFM. Circuit R-G also starts IFM after 1-second delay.
Should room temperature continue to fall, circuit R-W is
made through second-stage thermostat bulb. If optional elec-
tric heat package is used, a relay is energized, bringing on
first bank of supplemental electric heat. When thermostat
is satisfied, contacts open, deenergizing contactor and re-
lay; motors and heaters deenergize. The IFM may be con-
trolled by a time-delay relay that keeps the fan on for
30 seconds.
Defrost — Defrost board (DB) is a time and temperature
control, which includes a field-selectable time period be-
tween checks for defrost (30, 50, and 90 minutes). Elec-
tronic timer and defrost cycle start only when contactor is
energized and defrost thermostat (DFT) is closed.
Defrost mode is identical to Cooling mode, except OFM
stops and a bank of optional electric heat turns on to warm
air supplying the conditioned space.
— — — — —
0.11 0.12 0.13 0.14 0.15
— —
0.17 0.18