32
FIGURE 17. CONNECTION DIAGRAM
MCB-II DETAIL A
Part of J-BOX
VB/VW 1500/2000 WIRING DIAGRAM
ON/OFF MAIN POWER SWITCH
INPUT
120VAC
POWER
F2-20A
1
2
3
4
5
6
J1
F3-3A
1
2
3
6
7
J2
1
2
3
4
5
6
15
J3
F7-15A
F6-10A
POWER DISTRIBUTION
BOARD (PDB)
BLOWER
FUSE
PUMP FUSE
XFORMER
FUSE
MCB-II FUSE
TB1
TRANSFORMER
120/24 VAC
MODULATING
CONTROL BOARD II
(MCB-II)
J20 or J21
J16
1
2
6
7
J24
F1-7.5A
(24VAC)
J3
1
2
3
J1
1
2
3
A
B
B
C
D
E
PUMP
(EXTERNAL)
1 HP MAX
(SEE NOTE3)
J2
1
2
J18
1
2
J19
1
2
IGNITER
GAS VALVE
J9
3
4
J11
1
2
J8
2
3
J7
1
2
4
5
J17
1
2
3
4
5
6
FLAME SENSE
INLET PROBE
OUTLET PROBE
with MR HIGH LIMIT
REMOTE PROBE
Part of J-BOX
EXT ENABLE/DISABLE
BLOWER PROVER
BLOCKED INLET
J5
1
2
3
4
5
6
FLOW SWITCH
(OUTSIDE CABINET)
LOW GAS SWITCH
BLOCKED FLUE
BLOWER
1 2 3 5
1
2
3
CONFIGURATION KEY
J23
1
2
J4
1
2
3
4
5
6
7
8
LWCO BOARD
Part of J-BOX
24VAC SWITCHED
POWER
EXTERNAL POWER
ACCESSORY INTERFACE
PROVER
LWCO PROBE
SPLICES
EXTERNAL ALARM
CIRCUIT BOARD JUMPERS
MCB-II
–
JP1 (not used), JP2 (used
–
2.7A igniter),
JP3 & JP4 (used
–
removed for hipot test).
PDB
–
JP1 (used
–
run selection, JP2 & JP3 (used
–
removed for hipot test).
DIP SWITCH (SW1) FUNCTIONS
*
‘ON’ IS P OS ITION TOWAR DS B OAR D’S E DG E
.
1
–
Boiler type (
‘ON’ VB
,
‘OF F ’ VW
).
2
–
Ignition trials (
‘ON’
3,
‘off’
1).
3
– Must be ‘OF F ’
, IRI gas valve not an option.
4
–
Control probe (
‘ON’ tank
,
‘OF F ’ inlet
).
5
–
Power accessory (
‘ON’ if used
).
6
–
Low water cutoff (
‘ON’ if used
).
7
– Must be ‘ON’
, low gas switch always used.
8
–
Spare (n/a).
9
–
Spare (n/a).
10
–
Spare (n/a).
MCB-II DETAIL B
DIP SWITCH (SW2) FUNCTIONS
*
‘ON’ IS P OS ITION AWAY F R OM B OAR D’S E DG E
.
1
–
Spare (not used).
2
–
High gas switch (
‘ON’ if used
).
3
–
Spare (not used).
SEE MCB-II DETAIL B
SEE MCB-II DETAIL A
SW1
OFF
ON
1
SW2
ON
OFF
1
1
2
3
4
5
6
7
8
9
10
EXTERNAL ALARM
EXTERNAL POWER
ACCESSORY INTERFACE
24VAC SWITCHED
POWER
PROVER
HIGH GAS SWITCH
COM
NO
COM
NO
NO
COM
COM
COM
COM
NO
NC
NC
NO
COM
HIGH GAS SWITCH
COM
NC
USER INTERFACE MODULE
(UIM)
BUILDING
MANAGEMENT
INTERFACE (BMI)
1
2
J3
J8
J9
1
2
3
(OUTSIDE CABINET)
THRU CABINET
0-10VDC
INPUT
SIGNAL
J12 or J13
F
F
DS2 MAIN MICRO
YELLOW LED (2 HERTZ
FLASH NORMAL)
DS3 FLAME MICRO
YELLOW LED (2 HERTZ
FLASH NORMAL)
DS2 GREEN LED
(ON NORMAL)
DS1 YELLOW LED
(OFF NORMAL)
DS3 RED LED
(OFF NORMAL)
DS1 GREEN LED (ON WHEN
BOILER FOUND)
DS2 BMI MICRO GREEN LED
(2 HERTZ FLASH NORMAL)
BUILDING
MANAGEMENT
INTERFACE (BMI)
1
2
J3
J8
J9
1
2
3
(OUTSIDE CABINET)
0-10VDC
INPUT
SIGNAL
DS1 GREEN LED (ON WHEN
BOILER FOUND)
DS2 BMI MICRO GREEN LED
(2 HERTZ FLASH NORMAL)
LEGEND
120VAC WIRING
LOW VOLTAGE WIRING
CAT-5 COMM CABLE
AVAILABLE OPTION
NOTE1: IF ANY OF THE ORIGINAL WIRE AS SUPPLIED
WITH THE APPLIANCE MUST BE REPLACED, REPLACE
WITH EQUIVALNET GAUGE WIRE, INSULATION TYPE
105°C, 600 VOLTS.
(317415-000 REV 1)
NOTE2: UNIT MAY HAVE ALL, SOME, OR NONE OF
THE OPTIONS.
BK
W
G
BK
BK
W
G
W
BK
BK
Part of J-BOX
BK
BK
BK
W
G
C
D
E
BK
W
BK
BK
W
W
G
G
BK
W
BK
W
BK
W
R
R
R
BK
BL
Y
G
W/BK
W/BK
BK/W
BK/W
BK/W (24VAC HOT)
W/BK (24VAC RTN)
G (GROUND)
BK/W (24VAC HOT)
W/BK (24VAC RTN)
G (GROUND)
Y (+5VDC)
Y
Y
Y
BK/W
Y/V
BK/W
R/G
BK/W
R/G
BL
BL (+5VDC)
BK (+5VDC)
BK
R (+24VDC)
R
BK/W
Y/V
BK/W
R/G
BK/W
R/G
BK/W
R/G
BK/W
R/G
CAT-5 CABLE
CAT-5 CABLES
CAT-5 CABLE
EXT ENABLE/DISABLE
COM
NO
BL (RPM FEEDBACK)
Y/R (0-10VDC COMMAND)
R (+24VDC)
BK/W (0-10VDC RTN)
BK
R
BK/W
–
POWER ACC 24VAC
W/G
–
POWER ACC PROVER
W/BK
–
POWER ACC 24VAC RTN
BK/W
–
ALARM 24VAC
W/BK
–
ALARM 24VAC RTN
BK/W
R/G
W/BK
W/BK
–
24VAC RTN
R
3 2 1
3 2 1
L1
L2
NO
LLCO
G
COM
BK/W
R/G
–
LWCO INPUT
BK/W
–
24VAC
G
LWCO BOARD
LWCO PROBE
W/BK
–
24VAC RTN
R
3 2 1
L1
L2
NO
LLCO
G
COM
BK/W
R/G
–
LWCO INPUT
BK/W
–
24VAC
G
DS1 RED LED (ON FOR
BLOWN F1 FUSE)
(External Comm) (Internal Comm)
ST1
ST2
P1
C1
GV
PUMP
(EXTERNAL)
1 HP MAX
(SEE NOTE3)
NOTE3: VW UNITS COME EQUIPPED WITH PUMP, VB
UNITS DO NOT.
COM
NC
NO
COM
COM
NC
24VAC
COM
PUMP RELAY
A
BK
ON/OFF
POWER RELAY
NO
COM
G
W
W
BK
BK
BK
BK
BK/W ((24VAC HOT))
W/BK ((24VAC RTN))
G ((GROUND))
F
CAT-5 CABLE
F
R/G
BK/W
