Diagrams; Ladder Diagram - Lochinvar Shield SNR150-100 Installation & Service Manual

13

Diagrams

Figure 13-1 Ladder Diagram
EXTERNAL
CONTROL
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.
74
120VAC
TERMINAL STRIP
120V SUPPLY "L"
PUMP
RELAY
4 3
INTEGRATED CONTROL
X1-6
F5 X1-3
5A DHW PUMP
RELAY
X1-8
F4
X1-1
JUNCTION
3.5A
BLOWER
BOX
RELAY
F3
1.25A
X1-5
120 VAC
F2
X5-7 X6-8
24 VAC
X6-7
3.5A
X6-3
X6-2
CONNECTION CONNECTION
BOARD BOARD
CN2-6 CN5-1
CN2-12
MANUAL RESET
HIGH LIMIT X5-14 X6-4 CN2-5
INTEGRATED
CONTROL
DISPLAY
X3
RIBBON CABLE
PC
INTERFACE
S2
INLET
SENSOR
S1
OUTLET
SENSOR
S3
FLUE
SENSOR
CONNECTION BOARD
CN4-11
3
RUN-TIME
CN4-12
CONTACTS
4
CN4-10
5
ALARM
CN4-4
CONTACTS
6
CN4-1 CN3-8
S4
TANK
CN4-4 CN3-6
SENSOR
CN4-5 CN3-10
+
0-10V
CN4-2 CN3-4
-
JUNCTION BOX NEUTRAL
TERMINAL STRIP
120V SUPPLY "N"
GND
DHW
DHW
PUMP "L"
PUMP "N"
DHW
PUMP
TERMINAL TERMINAL
STRIP STRIP
PUMP
RELAY COIL
2
1
BLOWER
1 2
3
JUNCTION BOX
CN2-4
CN2-10
CN5-2
LWCO
CN5-3 CN5-4
LOW GAS HIGH GAS
CONNECTION
PRESSURE PRESSURE
BOARD
SWITCH SWITCH
CN4-6 CN4-3
INTEGRATED
CONTROL
EXTERNAL
LIMIT
AIR PRESSURE
X8
BLOCKED
X5-8
DRAIN
SWITCH
AUTO RESET
X5-1
O-TEMPHEX SW
HI-LIMIT
GAS VALVE
X5-2
X5-9
BLOWER
X3-1
X3-3
X3-4
X3-2
SPARK
ROD
X4-8
CAUTION HIGH VOLTAGE SPARK LEAD
X4-6
X4-10
X4-4
Installation & Service Manual
TM
GROUND
BOX DEPICTS
OPTIONAL ITEMS
LOW VOLTAGE
120 VAC
HIGH VOLTAGE
CONNECTION
BOARD
INTEGRATED
CONTROL
CN2-11 X6-9
CN2-3 X6-5
2
CN2-9 X6-10
1
X5-11
SWITCH
X5-4
X5-3
X5-10
X2-2
GAS VALVE
RELAY
X2-1
1 X5-5
2 X5-13
4 X5-6
5 X5-12
TR1
X1-7
FLAME ROD

LADDER DIAGRAM

LBL20026 REV C