Carrier 38VMH-1P Service Manual page 51

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F1: DC BUS VOLTAGE TOO LOW
DEFINITION
If DC bus voltage of compressor module P and N is less than 200 VDC for five seconds, relay on the main board is inoperable.
POSSIBLE CAUSES
• Abnormal power supply to power drive board
• Damaged rectifier
• Damaged DC fan motor
• Damaged power drive board or main board
• The communication wire between power drive board and main board is loose
Note: Check the voltage between red and black terminals.
Note: Check whether the PFC and IPM in power drive are
shorted.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Fig. 58 —F1 Troubleshooting Chart
Note: Check whether these three voltage are normal or not.
A210294
51
A210293
A210295