Lennox MPA012S4S-1L Service Manual page 147

Pic 2
Pic 1: Use a multimeter to test the
DC voltage between L2 port and S
port of outdoor unit. The red pin of
multimeter connects with L2 port
while the black pin is for S port.
When AC is normal running, the
voltage will move alternately between
positive value and negative value.
Pic 2: IPM (for 2-zone/3-zone)
Power (some
Power (some
models)
modles)
Self-Check OK
Opera ng
Lennox Mini-Split Service Manual / Page 147