Zero-Crossing Signal Error; Indoor Fan Speed Has Been Out Of Control(Dc Fan Motor); Dc Motor Voltage Input And Output - Heat Controller A-VMH18DC-1 Service Manual

Service Manual

9.3.1.3 Zero-crossing signal error

Check if the connections and
power supply is normal?
Indoor PCB is defective.
Replace indoor PCB.

9.3.1.4 Indoor fan speed has been out of control(DC fan motor)

Shut off the power supply and
turn it on 5 seconds later. Is it
still displaying the error code?
Shut off the power supply,
Shut off the power supply, rotate the fan
rotate the fan by hand. Does
by hand. Does it rotate freely with any
rubbing/obstructions? it rotate properly?
Check the wires of fan motor.
Are all the connections good?
Check the voltage between port
1 and 6 of fan motor connector,
Replace indoor main PCB. Is it
still displaying the error code?
4
1
are normal?
Yes
Yes
Yes
Yes
is it 310V?
No
No

DC motor voltage input and output

5
NO.
1
6
2
3
4
5
3
6
2
VMH SerieS
Correct the connections. Turn on the unit
Correct the connections. Turn on the
when the power supply is within 90-110% of
No
unit when the power supply is good.
rated voltage on unit's rating plate.
No The unit operates normally.
Replace indoor fan
No
No Correct the connections.
Correct the connections
per wiring diagram.
The unit operates normally.
Color Signal
Red V
DC
--- ---
White Vcc
Blue FG
Yellow Vsp
Black GND
30
motor.
Yes
Voltage
310V
---
15V
0.3V
0-7.5V
0V
Heat Controller, Inc.