Carrier 40MBFAQ Service Manual

40MBFAQ: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
33
DIAGNOSIS AND SOLUTION (CONT.)
EH bA (Communication malfunction between the external fan module and indoor unit)/EH 3A(External fan DC
bus voltage is too low protection)/ EH 3b (External fan DC bus voltage is too high fault Diagnosis and Solution)
Description: The indoor unit does not receive feedback from the external fan module during 150 seconds or the indoor unit
receives abnormal increases or decreases in voltage from the external fan module.
Recommended parts to prepare:
• Indoor main PCB
Troubleshooting
Shut o the power supply and
turn it on 2 minutes later.
Is it still displaying
the error code?
Replace the indoor main PCB.
The unit is operating normally.
Check if ENC 1
is correct.
Reset the ENC 1
Yes
Yes
No
No

Carrier 40MBFAQ Specifications

General

Brand	Carrier
Model	40MBFAQ
Category	Heater
Language	English