Lochinvar 502, 2072 Ladder diagram, Installation & Operation Manual, Low Voltage, 120 VAC

Installation & Operation Manual

10 Ladder diagram

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

X10-4

X12-4

DEPENDING UPON WHETHER UTILITIES ARE CONNECTED OR A FAULT

CONDITION IS PRESENT. SEE WIRING DIAGRAM FOR ADDITIONAL NOTES.

BOX DEPICTS OPTIONAL ITEMS

LOW VOLTAGE

120 VAC

X10-5

X10-6

X12-5

X12-6

UNIT PUMP RELAY

1 GAS VALVE

2 GAS VALVE

3 GAS VALVE

4 GAS VALVE

CHASSIS

CONTROL BOARD

STAGE

STAGE

STAGE

STAGE

N G

TERMINAL STRIP

X10-2

X10-3

X12-2

X12-3

BLOWER

N

BLOWER RELAY

HI/LO SPEED RELAY

UNIT PUMP RELAY

RECIRC PUMPRELAY

DHW PUMP RELAY (BOILER)

X13-

X112-

X12-

X13-

TRANSFORMER

INTERGRATED

X10-1

X12-1

X6-4

HIGH SPEED

LOW SPEED

SYSTEM/

STRIP

TRANSFORMER

TERMINAL STRIP

HI/LO SPEED

RELAY

HI/LO SPEED RELAY

INTERGRATED CONTROL BOARD

X1-8

X2-4

X1-2

TERMINAL

X1-1

X1-4

STAGEHSI1

X1-7 X110-

STAGEHSI3

X2-1 X22-

MODBUS INTERFACEBOARD

FUSE

BREAKER

BLOWER

RELAY

ON/OFF WISTCH

X1 -6

F2

3.15A

F4

5A

F5

5A

F6

5A

X1-1

CIRCUIT BREAKEROR

CIRCUIT

MANUAL RESET

HIGH LIMIT

L

NOTE: Not all connections/features apply to pool heaters.

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