Bryant SM03-4 Service Manual page 7

THIS COMPARTMENT MUST BE CLOSED EXCEPT FOR SERVICING
FIELD POWER WIRING
HVTB
L1
YEL
FU5
YEL
CB/FU3
YEL
CB/FU1
YEL
9
9
SPT
YEL
YEL
RED-LO
FM
BRN BLU-MED
BRN
BLK-HI
YEL-COM
GRN/YEL-GND
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. TRANSFORMER PRIMARY LEADS, BLUE 208V, RED 230V.
4. IF ANY OF THE ORIGINAL WIRE, AS SUPPLIED, MUST BE REPLACED,
USE THE SAME OR EQUIVALENT TYPE WIRE.
5. REPLACE LOW VOLTAGE FUSE WITH NO GREATER THAN 5 AMP FUSE.
6. 20KW HEATER USES ONE DOUBLE POLE LS ON MIDDLE TOP ELEMENT.
7. 18, 24 AND 30KW HEATERS USE DOUBLE POLE LIMIT SWITCHES.
8. LARGEST HEATERS ARE SHOWN, SMALLER HEATERS WILL HAVE FEWER ELEMENTS AND
COMPONENTS.
9. 1 PHASE HEATERS ARE SHOWN WIRED FOR SINGLE SUPPLY CIRCUIT.
10. USE 60 AMP CLASS K FUSES ONLY, FOR REPLACEMENT.
11. (3) SPEED MOTOR SHOWN. OPTIONAL (2) SPEED MOTOR USES HI (BLK) AND LOW
(BLU OR RED).
12. CONNECT R TO R, G TO G, ETC., SEE OUTDOOR INSTRUCTION FOR DETAILS.
13. IF WIRE CRIMP IS REMOVED AN EMERGENCY HEAT RELAY IS REQUIRED.
(SEE OUTDOOR-THERMOSTAT INSTRUCTIONS)
voltage applied to low-voltage circuit, or a direct secondary short.
When there is a high current draw on transformer, it is most likely
because transformer has been shorted or system is trying to draw
more VA than transformer rating allows. When fuse blows because
of high voltage, the system has mixed high- and low-voltage
signals.
1. Check wiring of sequencers/relays as shown in Fig. 4 and 5.
Be sure transformer is not shorting out because thermostat
wires are miswired.
2. Check wiring of sequencers/relays as shown in Fig. 4 and 5.
Be sure low-voltage and high-voltage wiring is correct.
BLOWER MOTOR
ROTATION
30KW 1PH SCHEMATIC DIAGRAM
DISCONNECT PER NEC
SEE RATING PLATE
FOR VOLTS & HERTZ
GND
SEE NOTE #1
HTR6 BLK
LS6
YEL BLK
11
12
SEQ 3
HTR5 BLK
LS5 BLK
YEL
10 9
HTR4 BLK
BLK
YEL LS4
8
7
SEQ 2
HTR3 BLK
BLK
YEL LS3
6 5
HTR2 BLK
YEL LS2
BLK
4 3
SEQ 1
HTR1 BLK
YEL LS1
BLK
2 1
YEL
BLU
BLK
SEQ1
ORN
BLK
BLU
11 7 3
11 3
7
BLU BLK
NC GRY
G
RED
NO
R
FR
F
BRN
T
1
PCB
C
208V 230V
C
R
RED
BARRIER
TRAN
BRN
INDOOR
THERMOSTAT
Fig. 4—Wiring Diagram of Sequencer Heater
CAP CAPACITOR
COM COMMON
F LOW VOLTAGE FUSE
FM FAN MOTOR
FIELD POWER WIRING
FR
PCB FAN RELAY
L2
FU LINE FUSE
GND EQUIPMENT GROUND
FU6
HVTB
HIGH VOLTAGE TERM BLOCK
BLK
HTR HEATER
BLK
CB/FU4
COOLING CONTROL ONLY
BLK
CB/FU2
FIELD
SEQ2 POWER
WIRING
BRN
L1
RED
YEL
SEQ3
BRN
9
VIO
GRAY
208/240VAC
PLUG
9
2 6 1 4
2 6 1
4
RECP
BRN
FIELD POWER WIRING
HVTB
W2 W3 E
YEL
L1
Y
W2
FU5
G
E
WHT
SEE NOTE #13
L
SEE NOTE #12
OUTDOOR
UNIT
CB/FU3
YEL
CB/FU1
9
208/240VAC
321214-101 REV. C
3. Check VA draw on transformer. If VA draw is more than
VA rating of transformer, fuse will blow. If this is the case,
replace transformer with one that has a higher VA rating
and meets system specifications.
D. If Fan Runs Continuously:
1. If PCB has no low-voltage power, check blue and black fan
leads. These may be switched at sequencer/relay.
2. If PCB has low-voltage power, check fan relay to see if it is
opening and closing. It may be stuck in the normally-closed
position due to debris in relay.
—7—
CAUTION:
NOT SUITABLE FOR USE ON SYSTEMS EXCEEDING
150V TO GROUND
ATTENTION:
LEGEND
LS LIMIT SWITCH
MARKED TERMINAL
PLUG AND RECEPTACLE
PCB PRINTED CIRCUIT BOARD
SEQ SEQUENCER
TRANSFORMER
TRAN
UNMARKED TERMINAL
RECP RECEPTACLE
CIRCUIT BREAKER
CB
FIELD POWER WIRING
L2
BLK
11 7 6 1
3 2
24VAC
6 1
11 7 3 2
30KW 3PH SCHEMATIC DIAGRAM
DISCONNECT PER NEC
SEE RATING PLATE FOR VOLTS & HERTZ
GND
SEE NOTE #1
BLK
L3
HTR6 BLK
LS6 BLK
YEL
11 FU6
12
SEQ 3
HTR5 BLK
BLK
LS5
YEL
9
10
HTR4 BLK
BLK
YEL LS4
8
7
CB/FU4
SEQ 2
HTR3 BLK
BLK
YEL LS3
6 5
HTR2 BLK
BLK
YEL LS2
3
4
CB/FU2
SEQ 1
HTR1 BLK
BLK
YEL LS1
1
2
SEQ2
RED
SEQ3
SEQ1
ORN VIO GRAY
11 7 3 2 6 1
24VAC
PLUG
4
24VAC
4
RESP
L2
BLK
BLK
BRN
BRN
PLUG
4
24VAC
A94346