Operating Sequence; Base Unit Controls; Indoor (Supply) Fan; Cooling, Unit Without Economizer - Two-Stage Units - Carrier Bryant 575J 07 Series Installation, Start-Up And Service Instructions Manual

OPERATING SEQUENCE

Base Unit Controls

INDOOR (SUPPLY) FAN

If the thermostat fan operation is selected as Continuous, then
the indoor (supply) fan motor, which is remotely located in the
fan coil, runs continuously. If the thermostat fan operation is
selected as Automatic, then the indoor (supply) fan motor runs
when there is a call for Ventilation, Cooling, or Heating. When
thermostat is satisfied, then the indoor (supply) fan motor
stops. If there is a fan fault or a shutdown condition in the fan
coil, then the indoor (supply) fan will not run if there is a call
for ventilation, cooling, or heating and the 575J unit will act as
if it is not receiving a thermostat demand.
COOLING, UNIT WITHOUT
TWO-STAGE UNITS
For two stage units, the 575J*07G/H and 575J*08M/n use a
two-stage Copeland ™1 Ultratech Scroll compressor in conjunc-
tion with a two-stage Comfort Alert Module (CADM). The
1. Third-party trademarks and logos are the property of their respective
owners.
10 Ton Heat Pump Dual Stage Charging Chart R-410A
(compressor full load, all condenser fans operating)
Fig. 18 — 575J*12G/H Charging Chart
ECONOMIZER —
PN: 38AU000486 REV -
575J*12G/H uses two compressors in tandem on a single cir-
cuit in conjunction with two single-stage Comfort Alert Mod-
ules (CADM).
575J*07G/H and 575J*08M/N
When thermostat calls for Stage 1 Cooling, terminal Y1 is en-
ergized. The 575J unit's Defrost Board (DFB) receives this in-
put at P2-5. DFB issues 24-v outputs at OF, P3-7 (RVS1) and
P3-10 (COMP1). The OF output energizes outdoor fan relay
(OFR); both outdoor fan motors start and run. The output
RVS1 energizes the reversing valve solenoid (RVS); Reversing
valve switches to Cooling position. Output PL3-10 (COMP1,
24-v) is received at CADM terminal Y. If anti-recycle time de-
lay period has not expired, safety pressure switches are open,
and/or lockout alarms are active, CADM relay will remain
open, preventing compressor start. When safety pressure
switches are closed and CADM time delay expires, the CADM
relay closes, energizing Solenoid Valve Relay SVR and com-
pressor contactor C. SVR contacts close, energizing the exter-
nal liquid line solenoid valve. Solenoid valve LLSV opens.
Compressor contactor C closes, energizing the compressor mo-
tor. Compressor starts and system runs in Stage 1 Cooling
mode.
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