Bryant 575B User Manual
wiring diagrams
SPLIT-SYSTEM HEAT PUMP UNITS
Cancels: WD 575C.90.1 WD 575B.72.1
DIAGRAM INDEX
575C/575B
Sizes 072 to 120
with
524A-H
6/15/03
UNIT SIZE
575B
575C
524A-H
*Units produced after 3/31/03.
C—
CAP —
CB —
CCH, CH —
CDT —
CLO —
COMP —
CTD —
DFC —
DFT —
DGT —
EQUIP —
FM —
GND —
HP, HPS —
IFC —
IFM —
072
090-120
090-120 Applies to all Unit Wiring Diagram Not Available 9
Contactor, Compressor
Capacitor
Circuit Breaker
Crankcase Heater
Contactor Dummy Terminal
Compressor Lockout
Compressor
Compressor Time Delay
Defrost Control
Defrost Thermostat
Discharge Gas Thermostat
Equipment
Fan Motor
Ground
High-Pressure Switch
Indoor-Fan Contactor
Indoor-Fan Motor
CHARACTERISTICS
ELECTRICAL
(V-Ph-Hz)
208/230-3-60
460-3-60 2
575-3-60 2
208/230-3-60
460-3-60 38AK540180 5 or 6*
575-3-60 38AK540211 7 or 8*
Control Schematic and Component Arrangement Not available
Control Schematic and Component Arrangement
TYPE
LABEL DIAGRAM
NUMBER
38AK540179 3 or 4*
FIGURE NO.
LEGEND (Fig. 1-9)
LAR —
LAS —
LCS —
LLSV —
LP, LPS —
MMR —
NEC —
OF, OFM —
OFR —
PL —
PS —
RV —
RVS —
TB —
TRAN(S) —
T’STAT —
Low Ambient Relay
Low Ambient Switch
Loss-of-Charge Switch
Liquid Line Solenoid Valve
Low-Pressure Switch
Motormaster® Relay
National Electrical Code
Outdoor-Fan Motor
Outdoor-Fan Relay
Plug
Pressure Switch
Reversing Valve
Reversing Valve Solenoid
Terminal Block
Transformer
Thermostat
Field Splice
Marked Wire
Terminal (Marked)
Terminal (Unmarked)
Terminal Block
Splice
Factory Power W ir in g
Factory Control Wiring
Field Control Wiring
Field Power Wiring
Accessory or Optional Wiring
To indicate common potential only,
not to represent wiring.
1
NOTES (Fig. 1 and 2)
1. F actory wiring is in accordance with N at i on al E l ec tr ical Code (NEC). Field modifications or additions
must be in compliance with all applicable codes.
2. Use copper conductors onl y.
3. CAUTION: Not suitable for use on systems exceedin g
150 volts to ground.
4. Manual reset circuit breaker is integral to the
transformer.
NOTES (Fig. 3-8)
1. If any of the original wire furnished must be
replaced, it must be replaced with type 90° C wire or
its equivalent.
2. For thermostat and subbase part no. see price pages.
3. Set heat anticipator at .6.
4. Use copper conductors only.
5. Three-phase motors are protected under primary
single phasing conditions.
6. 39 VA available for field-installed acces sories. Control
power requirement for heat pump condensing unit is
36 VA (sealed). Supplied control transformer is 75 VA.
NOTES (Fig. 9)
1. Factory wiring is in accordance with National Electrical Code (NEC). Field modifications or additions
must be in compliance with all applicable codes.
2. Use copper conductors only.
SEQUENCE OF OPERATION —
575B OUTDOOR UNIT WITH
524A-H INDOOR UNIT
When power is supplied to unit, the transformer (TRAN) and
crankcase heater (CCH) are energized.
Cooling
On a call for cooling, the thermostat c ompletes the following
circuits: R-G, R-Y, and R-O. If the compressor recycle delay of
3 minutes is complete, the compre ssor and outd oo r fan sta rt.
The reversing valve is en ergized for cooling and the indo orfan motor starts.
When the thermostat is satisfied, the circuits are opened,
and the compressor, outdoor-fan motor, and indoor-fan motor
stop. The reversing valve is dee nergized.
Heating
On a call for heating, the thermostat completes the following
circuits: R-G and R-Y. If the compressor recycle delay of
3 minutes is complete, the compre ssor and outd oo r fan sta rt.
The indoor-fan motor will also start.
If room temperature continues to fall, the thermostat completes circuit R-W. If the optional electric heat package is
used, the hea t r elay is energized, and the elect ri c hea t ers are
energized.
When the thermostat is satisfied, the circuits are opened,
and the compr essor, outdoor-fan motor, heaters, and indoorfan motor stop.
Defrost
The Defrost board (DB) is a time and temperature control,
which includes a fiel d-sele ctab le time per iod between checks
for frost (30, 50, and 90 minutes). Electronic timer and
defrost cycle start only when contactor is energized and
defrost thermostat (DFT) is closed (below 36 F [2.2 C]).
Defrost mode is identical to Cooling mode, except outdoor-fan
motor (OFM) stops and a ban k of supp lemen tal ele ctric h eat
(if equipped) turns on to warm air supplying the conditioned
space. Defrost mode is terminated when the DFT reaches
51 F (10.6 C).
Low Ambient
Cooling head pressure control at low ambient conditions is
accomplish ed through a low ambien t relay and switch. The
switch is factor y se t to close at 250 psig and open at 100 psig .
In Heating mode, the low ambient switch is bypassed by normally closed contacts on the low ambient relay.
Air Circulation
When the fan switch is at FAN ON, the indoor-air fans operate continuously to provide ventilation. The thermostat operates the other components as described above.
Emergency Heat Cycle
If the compressor is inoperative due to a tripped safety
device, the second stage of the thermostat automatically
energizes the ind oor-air fan and th e el ectric resis tance h eaters (if equipped).
SEQUENCE OF OPERATION —
575C OUTDOOR UNIT WITH
524A-H INDOOR UNIT
When power is supplied to unit, the transformer (TRAN) is
energized. The crankcase heater is also energized.
Cooling
With the thermostat 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 mak es, closing circu it R-Y. When compressor time delay (5 ± 2 minutes) is completed, a circuit is made
to contactor (C), starting the compressor (COMP) and
outdoor-fan motor (OFM). Circuit R-G is made at the same
time, energizing the ind oor-fan contactor (IFC) and sta rting
the indoor-fan motor (IFM) after one-second delay.
When the thermostat is satisfied, contacts open, deenergizing C. The COMP, IFM, and OFM stop.
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 energizes IFC and starts IFM after a 1-second delay.
Should room temperature continue to fall, circuit R-W is
made through second -s tage thermostat bulb. If optional electric heat package is used, a relay is energized, bringing on
supplemental electric heat. When thermostat is satisfied,
contacts open, deenergizing contac tor and relay; motors and
heaters deenergize.
Defrost
Defrost board (DB) is a time and temperature control, which
includes a field-selectable time period between checks for
frost (30, 50, a nd 90 minutes). Electron ic timer and defrost
cycle start only when contactor is energized and defrost thermostat (DFT) is closed (below 28 F [–2.2 C]).
Defrost mode is identical to Cooling mode, except outdoor-fan
motor (OFM) stops and a bank of supplemental electric heat
turns on to warm air supplying the conditioned space.
Defrost mode is terminated when the DFT reaches 65 F
(18.3 C).
—2—
CONNECTION DIAGRAM
LOW AMBIENT
SWITCH
BL
LOW
AMBIENT
RELAY
COIL
R
3
1
2
PRI
BL
TRANS
G
SEC
BK
BL
PL
BK
(WHEN
BL
USED)
CAP
BR
BR
FM
T3
COMP
T1
R
R
DANGER: ELECTRICAL SHOCK HAZARD
DISCONNECT POWER BEFORE SERVICING
BL
R
R
T2
BL
BK
L3
T3
L2
T2
T1
L1
COIL
BK
BK
CCH
POWER SUPPLY PER
N.E.C. AND LOCAL
CODES 208/230 VAC,
60 HZ, 3 PH.
L3
GROUND EQUIPMENT
PER N.E.C. AND
L2
LOCAL CODES.
BK
L1
ATTACH GROUND
208/230 VAC, 60 HZ, 3 PH POWER SUPPLY
L3
T3
R
DEFROST
CONTROL
FAN
R
BL
R-RV
BL
O
Y-R V
RV
BK
COIL
RV
CC
PS2
PS1
DF
O
C
BL
R
BK
BL
BL
Y
Y
BK
SEN
BK
Y
WR
TWO SWITCH WIRING
W
Y
O
DEFROST HEAT
COMPRESSOR
HEAT/COOL
PS2
PS1
LP/HP
LP/HP
COMMON
24 VAC
LADDER DIAGRAM
CCH
+t°
CONTACTOR
CONTACTOR
T2
T3
T1
CAP
FM
208/230V
TRANSFORMER NOTE 4
24V
Y-R V
FAN
RV
RESET
DEFROST
CONTROL
RRV
CC
PS2
PS1
DF
CRYWO
LAR
L2
T2
COMPRESSOR
LAS
LOW AMBIENT
21
RELAY
L1
T1
CONT.
DFC
FAN
(WHEN
USED)
RV
COIL
C
COIL
LP/HP
SEN
DEFROST HEAT
COMPRESSOR
HEAT/COOL
COMMON
24 VAC
Fig. 1 — Control Schematic and Component Arrangement — 575B072 (208/230 V)
—3—
CONNECTION DIAGRAM
BL
R
LOW AMBIENT
SWITCH
BL
LOW
AMBIENT
RELAY
COIL
3
1
BL
2
PL
BL
BK
G
CAP
BR
BR
FM
PRI
TRANS
SEC
R
R
BL
BL
BK
DEFROST
RELAY
R
R
BL
COIL
FAN
DANGER: ELECTRICAL SHOCK HAZARD
DISCONNECT POWER BEFORE SERVICING
R
R
T2
T3
COMP
T1
3
1
2
BL
BK
BK
L3
T3
L2
T2
L1
T1
BK
COIL
Y
Y
DEFROST
CONTROL
R-RV
Y-R V
BK
RV
COIL
RV
CC
PS2
PS1
DF
C
O
BK
BL
BL
Y
Y
BK
SEN
BK
Y
WR
W
BL
Y
O
O
R
575/460 VAC
60 HZ 3PH
L3
L2
BK
L1
ATTA CH
GROUND
CCH
LP/HP
PS2
PS1
LP/HP
TWO SWITCH WIRING
DEFROST HEAT
COMPRESSOR
HEAT/COOL
COMMON
24 VAC
L3
CONTACTOR
T3
T3
CAP
FM
575/460V
24V
RESET
LADDER DIAGRAM
575/460 VAC 60 HZ 3PH
CCH
+t°
L2
CONTACTOR
T2
T1
TRANSFORMER NOTE 4
DFR
FAN
DEFROST
CONTROL
R-
RV
T2
COMPRESSOR
LOW AMBIENT
RELAY
Y-R V
RV
CC
PS2
PS1
DF
CRYWO
LAR
LAS
L1
T1
CONT.
DEFROST
RELAY
RV
COIL
C
COIL
LP/HP
1
213
SEN
DEFROST HEAT
COMPRESSOR
HEAT/COOL
COMMON
24 VAC
Fig. 2 — Control Schematic and Component Arrangement — 575B072 (460 and 575 V)
—4—
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