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Page 40
H-ECB29 ‐8, ‐10 - 208/230V THREE PHASE - SEQUENCE OF OPERATION
1- When there is a call for heat, W1 of the thermostat
energizes the electric heat contactor K1.
2- When K1 contacts M1 and M2 close, the blower is ener
gized on heating speed.
3- When K1 contactor closes, assuming the N.C. primary
(S15) and secondary (S20) limit switches are closed,
electric heat elements HE1, HE2, and HE3 are ener
gized.