Figure 13-2 Ladder Diagram
BOX DEPICTS
OPTIONAL ITEMS
LADDER DIAGRAM
LBL20400 REV A
24 VAC
CN5-6
CN5-12
CN5-11
X4-2
X4-10
X4-11
INTEGRATED
CONTROL
LOUVER
RELAY COIL
24VAC
LOUVER
PROVING SWITCH
CN5-4
X4-4
X2-1
GAS VALVE
GAS VALVE
RELAY
X5-7
X5-16
X5-8
X5-15
1
2
4
5
TR2
X1-7
FLAME ROD
SPARK
ROD
CAUTION
HIGH VOLTAGE SPARK LEAD
BLOWER
CONNECTION
BOARD
INLET
SENSOR
OPERATING
SENSOR
FLUE
SENSOR
INTEGRATED
CONTROL
RUN-TIME
CONTACTS
RIBBON CABLE
X7
SYSTEM
SENSOR
TANK
SENSOR
OUTDOOR
SENSOR
0-10V
+
-
CASCADE
A
B
SHIELD
SHIELD
13
6
2
1
SILENCIN
G
SWI
TCH
AL
A
R
M
BEL
L
S6
S4
S5
BMS
CN6
X6
CN6
X6
CN6
X6
CN6
X6
CN6
X6
CN6
X6
CN6
X6
CN5-2
X4-6
CN5-9
X4-13
CN5-1
X4-7
CN5-8
X4-14
CN6
X6
CN6
X6
CN6
X6
HIGH LIMIT
SENSOR
FLUE
SENSOR
X5-4
X5-12
X5-5
X5-13
X5-14
X5-6
0-10V
+
-
SYS PUMP
IN
0-10V
+
-
BLR PUMP
OUT
0-10V
+
-
RATE
OUT
IN
MODBUS
A
B
SHIELD
SHIELD
CN6
X6
CN6
X6
CN6
X6
CN6
X6
CN6
X6
CN8-1
X6-1
CN8-2
X6-2
CN8-3
X6-3
X4-1
X9-2
X4-2
X9-1
X4-3
X9-3
PC INTERFACE
S2
S1a
S1b
S3a
S3b
21
22
26
27
23
24
30
31
32
33
35
36
37
38
39
40
41
42
43
44
3
4
1
2
ALARM
CONTACTS
M
O
D
B
U
S
29
34
9
5
6
7
8
X2-2
NOTES:
1. Where possible, switches are shown without utilities (gas, water or
electricity) connected to the unit. As such, actual switch states may
vary from those shown on diagrams depending upon whether utilities
are connected or a fault condition is present.
2. See wiring diagram for additional notes.
CN5-3
X4-5
3.5A
KB 801
ONLY
CN5-13
X4-9
CN5-7
X4-1
11
CN5-10 X4-12
CN5-14
X4-8
CN5-5
X4-3
LOW VOLTAGE
120 VAC
HIGH VOLTAGE
X5-2
X5-11
X5-10
AIR PRESSURE
SWITCH
BLOCKED
DRAIN SWITCH
O-TEMP
HEX SW
CONNECTION BOARD
19
17
15
13
10
LWCO
CN7-3
CN7-2
CN7-4
CN7-1
24 VAC
HEAT/LOOP
DEMAND
HEAT/LOOP
DEMAND
3
2
1
HEAT/LOOP
DEMAND
TANK
THERMOSTAT
HIGH GAS
PRESSURE
SWITCH
LOW GAS
PRESSURE
SWITCH
20
18
16
14
9
12
FLOW
SWITCH
120 VAC
120VAC
TERMINAL STRIP
120V SUPPLY "L"
ON / OFF
SWITCH
X1-6
X1-2
F2
NEUTRAL
TERMINAL STRIP
120V SUPPLY "N"
3.15A
F1
5A
INTEGRATED CONTROL
GROUND
JUNCTION BOX
BOILER
PUMP
DHW
PUMP
SYSTEM
PUMP
BOILER
PUMP
CONTACTS
DHW
PUMP
CONTACTS
SYSTEM
PUMP
CONTACTS
L
IN
L
OUT
RELAY BOARD
X1-1
1
2
BLOWER
SYSTEM PUMP
RELAY
DHW PUMP
RELAY
BOILER PUMP
RELAY
SYSTEM PUMP
RELAY
DHW PUMP
RELAY
BOILER PUMP
RELAY
24V DC
SUPPLY
F3
.8A
X5-1
X5-9
X1-3
X1-4
3
DOOR
TEMP
SW
13
Diagrams
(continued)
79
Installation & Operation Manual