Wiring Diagrams - Lennox CB26UH Unit Information

VIII−WIRING DIAGRAMS AND SEQUENCE OF OPERATIONS
CIRCUIT BREAKER 2 (OPT)
L1B
L2B
220
208/240
VOLTAGE
CIRCUIT BREAKER 1 (OPT)
BY
OTHERS
L1A
L2A
TO BLOWER
GROUND LUG
1 2
1 2
1
TRANSFORMER
COM
208V
240V
A−ECB26UH & ECBX26UH − SEQUENCE OF OPERATION
FIRST STAGE HEAT
1− Line voltage is routed to transformer and blower
relay.
2− 24VAC is supplied to indoor thermostat and electric
heat, if used.
3− When there is a call for heat W1 of the thermostat en-
ergizes sequencer relay 1.
4− Assuming limit switch 1 and 2 are closed, sequencer
relay 1 energizes HE1 and HE2.
5− Indoor blower is energized on heating speed, after se-
quencer timing is complete.
SEQUENCER 2
12 BK 5
12 BK
3
12 Y
GND
12 Y
SEQUENCER 1
5
12 BK
12 BK
3
12 Y
12 Y
GND
3 4
3 4
24
18 R
H
18 BU
C
TIME DELAY
H =10 TO 60 SECONDS TO HEAT UP
C =10 TO 60 SECONDS TO COOL DOWN
1
3
5
6
2
4
BLOWER
RELAY
6
ELECTRIC HEAT − 2ND STAGE
18 BK
12 BK
LIMIT SWITCH 3
4
7
1 12 BK
LIMIT SWITCH 4
3
ELECTRIC HEAT − 1ST STAGE
LIMIT SWITCH 1
4
12 BK
1 12 BK
LIMIT SWITCH 2
18 BK
6−PIN
PLUG
POWER (FACTORY WIRED)
5 6
POWER (FIELD WIRED)
CONTROL (FACTORY WIRED)
CONTROL (FIELD WIRED)
5 6
CONTROL CIRCUIT WIRING TO BE 24 VOLT, N.E.C. CLASS 2
6
18 BK W2
3
18 W W1
18 BU C
8
H 18 G G
18 R R
5
4
14 R (LO)
R
9 BLOWER
3
14 BK (HI)
BK
MOTOR
2
14 Y (COM)
Y+
1
SECOND STAGE HEAT
6− W2 in the thermostat energizes sequencer relay 2.
7− Assuming limit switch 3 and 4 are closed sequencer
relay energizes HE3 and HE4.
COOLING
8− When there is a call for cooling, G of the thermostat ener-
gizes blower time delay relay.
9− After a 30 second delay (approximate) blower relay ener-
gizes blower motor on cooling speed. Blower will also
delay 30 seconds after cool demand is satisfied.
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1 2 3
4 5 6
HEATER ELEMENTS USED:
5KW − HE1
BK
7.5 & 10KW − HE1 & HE2
15KW − HE1, HE2, & HE3
W
20KW − HE1, HE2, HE3, & HE4
BU
2
G
R
BR/W
BR MOTOR
CAPACITOR
6−PIN
PLUG