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B−ECB29-5, -5CB, -8, -8CB − 208/230V SINGLE PHASE − SEQUENCE OF OPERATION
1. When there is a call for heat, W1 of the thermostat
energizes the electric heat relay K32 with 24VAC.
2. When K32-1 closes, the blower is energized on
heating speed and economizer heat relay (K20-2) is
energized (see unit schematic, figure 26).
3. Assuming the N.C. primary (S15) and secondary (S20)
limit switches are closed, electric heat element HE1 is
energized.
4.
When K32-2 closes, assuming the N.C. primary (S15)
and secondary (S20) limit switches are closed, electric
heat element HE2 is energized.