PTAC Service Manual

Service Manual
Technical Information
60
6.2 Function Introduction
1. Basic function of system
1.1 Cooling mode (4-way valve is de-energized)
Under cooling mode, cooling mode indicator is ON and all the fan speed indicator is ON. Nixie tube displays set temperature and
SETOPINT is ON.
1.1.1 Working condition and process for cooling
a. When Tindoor amb.+Tindoor amb. compendationTpreset+2
o
F(1
o
C), the unit operates under cooling. Outdoor fan and indoor fan
operates. Compressor will operates 10s later.
b. Tindoor amb.+Tindoor amb. compendationTpreset-2
o
F(1
o
C), the unit sops operation. Compressor and outdoor fan stop operation.
Under fan cycle mode, indoor fan will stop operation after operating at set fan speed for 60s (except requiring the indoor fan to
operate in protection mode); if fan cycle mode is not selected, indoor fan will operate in set fan speed.
c. WhenTpreset-2
o
F(1
o
C)<Tindoor amb.+Tindoor amb. compendation<Tpreset+2
o
F(1
o
C), the unit keeps previous operation status.
1.1.2 Under this mode, nixie tube displays set temperature. The temperature setting and display range is 61-86
o
F(16-30
o
C); the
actual operation temperature range of controller is 61-86
o
F(16-30
o
C); 63-80
o
F(18-28
o
C), 65-78
o
F(19-26
o
C), 68-75
o
F(20-24
o
C) can be
selected by dial switch. (More details refer to special function)
1.2 Fan mode
Under this mode, fan mode indicator is ON and compressor stops operation. Temperature cant be adjusted (WARMER,COOLER
button are invalid). Indoor fan can operate at high, middle or low speed. Nixie tube displays ambient temperature (display range is
0
o
C-50
o
C or 32
o
F-122
o
F). Indoor indicator is ON. The default mode of fi rst energization (memory chip is empty) is fan mode; default
fan speed is middle. If exceeding the display range, min value or max value is displayed.
1.3 Heating mode
Under heating mode, heating mode LED and set fan speed LED is ON. Nixie tube displays set temperature. If select to display
ambient temperature in the fi fth mode of 6.5 confi guration mode, it will display as the way is this mode. The temperature and fan
speed will keep the same when changing from button setting to mode setting.
1.3.1 Working status
1.3.1.1 General type HEAT PUMP TYPE
Operation condition and process (electric heating and compressor cant operate at the same time)
a. When Tpreset-5
o
F(3
o
C)<Tindoor amb.-Tindoor amb. compensationTpreset-2
o
F(1
o
C), compressor operates at heating mode.
Meanwhile, 4-way valve, indoor fan and outdoor fan start operation. Compressor can operate after 10s. If compressor operates and
it satisfi es Tindoor amb.-Tindoor amb. compensationTpreset-5
o
F(3
o
C) and the minimum operation time for compressor, compressor
and outdoor fan stop operation immediately. 1s later, electric heater will start. Once the electric heating operates, it will quite until
is satisfi ed condition b (enter into protection function is excluded). When it needs to heat, if compressor cant be started up due
to protection function, electric heating will start heating instead of compressor 15s later. It will stop operation until satisfying the
temperature point. (customized requirement); When Tindoor amb.-Tindoor amb. compensationTpreset-5
o
F(3
o
C), the electric heating
operates. Indoor fan operates at set fan speed.
b. When Tindoor amb.-Tindoor amb. compensationTpreset+2
o
F(1
o
C), compressor or electric heating stops operation. Under fan
cycle mode, indoor fan operates at the condition of blowing residual heat; if fan cycle mode is not selected, indoor fan will operate in
set fan speed.
c. When Tpreset-2
o
F(1
o
C)<Tindoor amb.-Tindoor amb. compensation<Tpreset+2
o
F(1
o
C), the unit keeps previous operation status.
1.3.1.2 Pure electric heating type HEAT COOL TYPE
Operation condition and process
a. When Tindoor amb-Tindoor amb. compensationTpreset-2
o
F(1
o
C), the electric heating starts operation and indoor fan operates at
set fan speed;
b. When Tindoor amb.-Tindoor amb. compensationTpreset+2
o
F(1
o
C), the electric heating stop operation. Under fan cycle mode,
indoor fan operates at the condition of blowing residual heat; if fan cycle mode is not selected, indoor fan will operate in set fan
speed.
c. WhenTpreset-2
o
F(1
o
C)<Tindoor amb-Tindoor amb. compensation<Tpreset+2
o
F(1
o
C), the unit operates at previous operation
status.
1.4 OFF mode
If the OFF mode is selected, all the display will be closed except the power indicator and all the output are invalid. (Except the low
temperature protection). If press the WARMER or COOLER button, the dual 8 nixie tube will extinguish after it displayed the ambient
temperature for 15s and the INDOOR indicator will also go out after brighting for 15s. If repressing the WARMER or COOLER button
in the process of displaying the ambient temperature, 15s later, it will be calculated again.
1.5 Low temperature protection