Lennox LHT156

Page 44
Sequence of Operation LHT156/180/240
1 - 

ECONOMIZER OPERATION
2 - 
3 - 
1ST STAGE COOLING
4 - 
5 - 
are energized.
 A55 energizes outdoor fan B21 directly and fans B4 and B5 through K10.
7 - 
2ND STAGE COOLING
 
9 - 
10 - N.O. K2 closes energizing compressor B2 and K2-52 opens de-energizing crankcase heater HR2.
BLOWER OPERATION With By Pass
1 - 
2 - K203-1 N.C. contacts open to de-energize K3 relay coil. K3 contacts open to interrupt power to B3 blower motor through K3 N.O. relay contacts.
3 - 
BLOWER OPERATION No By-Pass
1 - 