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H–ECB29-5, -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 ener-
gized on heating speed and economizer heat relay
K43 is energized (see 208/230VAC CB schematic).
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.
Summary of Contents for CB29M-21
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