Lennox CB30M-65

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VIII–WIRING DIAGRAMS AND SEQUENCE OF OPERATIONS
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A–CB29M & CB30M – 208/230V SINGLE PHASE – SEQUENCE OF OPERATION
1- Line voltage is routed to transformer T1 and
blower motor B3.
2- T1 supplies 24VAC to terminal strip TB1, which
supplies 24VAC to the indoor thermostat and electric
heat, if used.
HEATING
3- When there is a call for heat, W1 of the thermostat
energizes the electric heat relay K32 (covered in the
electric heat section).
4- Blower motor B3 is energized on heating speed after
K32-1 closes (see electric heat).
5- Economizer relay K43 (if used) is energized after K32-1
closes (see electric heat section).
6- K43-1 closes energizing the economizer with 24VAC.
COOLING
7- When there is a call for cooling, G of the thermostat
energizes blower relay K3 and the economizer, if
used.
8- K3-2 closes energizing blower motor B3 on cooling
speed.