Carrier 38MGRBQ18B-3 Service Manual page 35

38MGRBQ: Service Manual
DIAGNOSIS AND SOLUTION (CONT)
Fig. 37 — Pic 1
Use a multimeter to test the DC voltage between 2 (old: L2) port and the outdoor unit's S port. The multimeter's red pin connects with 2 (old: L2) port
while the black pin is for S port. When the unit is running normally, the voltage moves alternately between the positive and negative values.
Operating
Standby
Fig. 38 — Pic 2: IPM (for 2 zone/3-zone)
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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