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G−ECB29-8, -10,−15CB − 208/230V THREE PHASE − SEQUENCE OF OPERATION
1. When there is a call for heat, W1 of the thermostat
energizes the electric heat relays K32 and K33 with
24VAC.
2. When K32-1 and/or K33-1 closes, the blower is energized
on heating speed and economizer heat relay (K20-2) is
energized (see unit schematic figure 26).
3. When K32-1, K32-2, and K33-2 closes, assuming the
N.C. primary (S15) and secondary (S20) limit switches
are closed, electric heat elements HE1, HE2, and HE3
are energized.
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