Heat Controller A-VMH18DC-1, A-VMH36QC-1 Abbreviations, Electric control working environment

Service ManualVMH SeriesHeat Controller, Inc.

8. Electronic control function

8.1 Abbreviations

T1: Indoor ambient temperature

T2: Coil temperature of indoor heat exchanger middle.

T2B: Coil temperature of indoor heat exchanger outlet.

T3: Coil temperature of outdoor heat exchanger

T4: Outdoor ambient temperature

T5: Compressor discharge temperature

Ts: Set point temperature.

8.2 Electric control working environment.

8.2.1Input voltage: 230V.

8.2.2Input power frequency:60Hz.

8.2.3Indoor fan normal working amperage. is less than 1A.

8.2.4Outdoor fan normal working amperage. is less than 1.5A.

8.2.5Four-way valve normal working amperage. is less than 1A.

8.2.6Swing motor: 12V DC.

8.3 Outdoor unit’s digital display

There is a digital display tube in outdoor PCB.

Digital display functions:

•In standby , the LED displays “- -”

•When compressor is operating, the LED displays the running frequency,

•In defrosting mode, The LED displays “dF” or alternatively displays between running frequency and “dF”(each displays 2s)

•In compressor pre-heating, The LED displays “- -”

•In protection or malfunction modes, the LED displays the associated error code or protection code.

8.4 Outdoor unit point check function

There is a check switch in outdoor PCB.

Push the switch SW1 to check the states of unit when the unit is running. The digital display will display the following each time the SW1 switch is preserved.

No.SW1	Display	Remark
Pressed
1	Indoor unit capacity demand code
2	Outdoor unit running mode code	Off:0, Cooling:1, Heating:2
3	Amendatory capacity demand code
4	Outdoor unit fan motor state	Off:0, Low speed:1, High speed:2
5	Evaporator outlet temp. for 1# indoor unit	Actual data is measured, however due to display limitations
		if the temp. is lower than -9 degrees, the digital display will
6	Evaporator outlet temp. for 2# indoor unit
		show “-9”. If the temp. is higher than 70 degrees, the digital
7	Evaporator outlet temp. for 3# indoor unit	display will show “70”. If the indoor unit is not connected, the
		digital display tube will show: “- -“.
8	Evaporator outlet temp. for 4# indoor unit
9	Condenser pipe temp.
10	Ambient temp.
11	Compressor discharge temp.	Actual data is measured, however due to display limitations
		if the temp. is lower than 0 degrees, the digital display will
		show “0”. If the temp. is higher than 99 degrees, the digital
		display will show single digit and a tens digit. For example if
		the digital display shows “0.5”, it means the compressor

20