Lennox LCH120H - Direct Drive Blower Sequence of Operation;Troubleshooting; Direct Drive Blower Operation; Direct Drive Blower Fault Sequence (No S52); Direct Drive Blower Fault Sequence (With S52)

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LCH092-152U STAGED SUPPLY AIR, DIRECT DRIVE BLOWER
Direct Drive EBM Blower Motor: The blower speed is deter
mined by thermostat demand and settings programmed into
the A55. When A55 receives a Y1 demand, a low speed volt
age output from A55 terminal 4 will energize B3 in low speed.
When A55 receives a Y2 demand, a high speed voltage output
from A55 terminal 4 will energize B3 in high speed. A55 output
voltage can be checked between A55 terminals 4 and 6.