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ECH16-5/7/10/15kW Y VOLTAGE
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ECH16-5 /15kW Y VOLTAGE SEQUENCE OF OPERATION
NOTE - Call for heat is first stage heat for CHA16 units and second stage heat for CHP16/20 units.
1- On a call for second stage heat, relay K43 is energized.
K43-1 closes immediately.
2- When K43-1 closes, heat relay K15 is energized.
K15-1 closes immediately.
3- K43-2 closes but nothing happens as indoor blower is
already energized from first stage heat call.
4- When K15-1 closes, heating elements HE1, HE2 and
HE3 are energized.
5- When heating demand is satified, heat relay K43 is de-
energized. All heating elements de-energize immediĆ
ately.