Lennox ELXA Series User Manual

Page 30
T3EH ELECTRIC HEAT SEQUENCE OF OPERATION (refer to gure 11) – 2 STAGE HEAT (50kW – Y Volt)
First Stage Heat Call
Heat Pumps (ELXP) - W1 heat demand operates the heat pump in heating mode.
Air Conditioners (ELXC) - W1 heat demand energizes the K9 heat relay.
K9−1 closes energizing K15, K16 contactors.
K15−1 closes energizing heating elements HE1 and HE2 assuming primary limit S15 and secondary limit S20 are closed
K16-1 closes energizing heating elements HE3 and HE4 assuming primary limit S15 and secondary limit S20 are closed.
Second Stage Heat Call
Air Conditioner (ELXC) − W2 heat demand energizes K19 contactor.
K19−1 closes, energizing one side of contactor K17 which energizes one side of K32 relay.
K32−1 closes energizing K17 contactor.
K17−1 closes, energizing heating elements HE5 and HE6 assuming primary limit S15 and secondary limit S20 are
closed.
Heat Pumps (ELXP) – W2 heat demand energizes K9 and K19 relays.
K9−1 closes energizing K15, K16 contactors.
K15−1 closes energizing heating elements HE1 and HE2 assuming primary limit S15 and secondary limit S20 are closed.
K16-1 closes energizing heating elements HE3 and HE4 assuming primary limit S15 and secondary limit S20 are closed.
K19−1 closes, energizing one side of contactor K17 which energizes one side of K32 relay.
K32−1 closes energizing K17 contactor.
K17−1 closes, energizing heating elements HE5 and HE6 assuming primary limit S15 and secondary limit S20 are
closed.

Lennox ELXA Series Specifications

General

Brand	Lennox
Model	ELXA Series
Category	Air Handlers
Language	English