Troubleshooting Pcb - Bryant SM03-4 Service Manual

L1
YEL
YEL
COM
HI
LO
NOTES:
1. Use copper wire (75¡c min) only between disconnect switch and unit.
2. To be wired in accordance with nec and local codes.
3. If any of the original wire, as supplied, must be replaced, use the same or
equivalent type wire.
4. Replace low voltage fuse with no greater than 5 AMP fuse.
5. (2) Speed Motor uses HI (BLK) and LOW (RED).
6. Smaller heaters will have fewer components.
7. Connect R to R, G to G, etc., see outdoor instructions for details.
8. Cooling controls wiring not used with electric heaters.
This compartment must be closed except
1. W2
When thermostat sends a signal to W2, a 24-vac signal is
applied across sequencer/relay number 1, causing it to
close. When sequencer/relay number 1 closes, first stage of
electric heat is energized. In straight electric heat, fan is also
energized through the normally-closed contacts of fan relay.
In cooling, heat pump, or manual fan mode, fan will already
be running since fan relay would have been energized.
When thermostat stops calling for electric heat, the 24-vac
signal to sequencer/relay number 1 turns off and sequencer
opens after a delay of 60 to 90 sec. Heaters equipped with
relays will be de-energized
sequencer/relay opens, first stage of heat turns off along
with fan, providing thermostat is not calling for the fan.
2. W3
When a signal is sent to W3, a 24-vac signal to
sequencer/relay number 2 causes it to close, with second
stage of electric heat turning on. The 24-vac signal applied
to sequencer/relay number 1 causes fan to operate. Timing
is such that sequencer/relay number 1 will turn on before
sequencer/relay number 2. When signal to W3 is turned off,
sequencer/relay number 2 opens. If W2 is also satisfied,
first stage of electric heat and fan will also turn off,
providing thermostat is not calling for the fan.
SCHEMATIC DIAGRAM
SEE RATING PLATE FOR VOLTS & HERTZ
FIELD POWER WIRING
COOLING CONTROLS
ELECTRIC HEAT
SEE NOTE #1
L1
DISCONNECT PER NEC
GND
SEE NOTE #6
YEL BLK
LS2 HTR2 BLK
8
RELAY 1
YEL
HTR1 BLK
LS1
4 2
BLU
YEL
BLK
BLU
BLK
BLK
SPT
NC
G
GRY
NO
R
FR
F
T
1
YEL
PCB
C
YEL
BRN
CAP
230V
COM 208V
BRN BRN
RED
YEL
BLK
TRAN
FM
BRN
GRN/YEL
INDOOR
RED
GND
THERMOSTAT
when servicing.
ROTATION
324494-101 REV. A
Fig. 3B—FF1D Typical Wiring Diagram
immediately. When
CAUTION:
NOT SUITABLE FOR USE ON SYSTEMS EXCEEDING 150V TO GROUND
ATTENTION:
NE CONVIENT PAS AUX INSTALLATIONS DE PLUS DE 150 V A LA TERRE
COMPONENT ARRANGEMENT
L2
L2
LS
HTR
SYSTEM TRANSFORMER: 40.0VA
FAN COIL/HEATER: 8.4VA
REMAINING VA AVAILABLE: 31.6VA
RELAY 1
8
6
BLK
4 2
6
0 1
BLK
REC
RELAY 1
L2 L1
22 VDC COIL
DISC
R E C 60A 60A
GND
VIO
ORN
RED-LOW
RED BLK-HI
GND
GRN/YEL-GND
ORN
GRY
SEE NOTE #5
RED
VIO
FAN MOTOR THERMALLY PROTECTED
R W G
C
CAP CAPACITOR
COM
COMMON
DISC
DISCONNECT
SEE NOTE #7
BARRIER
F
FUSE
FM
FAN MOTOR
OUTDOOR
FIELD POWER WIRING
UNIT
FR
PCB FAN RELAY
GND
EQUIPMENT GROUND
HTR
HEATER
LS LIMIT SWITCH
MARKED TERMINAL
PLUG AND RECEPTACLE
PCB
PRINTED CIRCUIT BOARD
REC
RECTIFIER
SPT
FAN SPEED TAP LOCATION
TRAN
TRANSFORMER
UNMARKED TERMINAL
MINIMUM MOTOR SPEED SELECTION
FAN COIL SIZE
MOTOR SPEED ONE HTR
MOTOR SPEED TWO HTR
3. E
When thermostat sends a signal to E, a 24-vac signal is sent
to sequencer/relay number 3. The 24-vac signal applied to
sequencer/relay number 3 turns on third stage of electric
heat. The 24-vac signal applied to sequencer/relay number
1 turns on first stage of electric heat and fan. When
thermostat stops calling for electric heat, the signal to
sequencers/relays 1, 2, and 3 are turned off, and
sequencers/relays open. This causes electric heat to turn off
with fan providing thermostat is not calling for the fan.
NOTE: Electric heaters are factory wired with all stages tied
together. If independent staging is desired, consult outdoor ther-
mostat installation instructions, or corporate thermostat instruc-
tions.
III. TROUBLESHOOTING
BOARD
Use wiring schematics shown in Fig. 4 and 5 as a guide in
troubleshooting PCB unless otherwise noted.
A. If Fan Will Not Turn On from Thermostat:
IF THERE IS NO HIGH VOLTAGE TO TRANSFORMER:
1. Check plug/receptacle connection. This supplies power
from heaters to PCB Fan Relay. Be sure plug is connected
properly.
—5—
LS
HTR
COM
RED
24 V
208 V
230 V
BRN
C
T
1
F
R
G
NC
PCB
NO
FR
SPT
BRN
FM
CAP
BRN
YEL-COM
LEGEND
018 024 030
LO LO LO
LO LO LO
THE PRINTED-CIRCUIT
A98229