Mini VRF SYSTEM
Trouble Diagnosis
3
3-51
4. Inspection of Parts (Outdoor Unit)
(1)
(2)
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
Electronic control valve (MOV1)
Crankcase heater
MOV1: Measure the voltage between plug pin 5 and pins 1 through 4 at the CN-MOV1 connector (5P, white)
on the outdoor unit control PCB. (Because of the pulse output, a simplified measurement method is used.
Set the tester to the 12 V range; if the value displayed is approximately 4 V, then the voltage is normal.)
If the voltage is normal, measure the resistance between connector pin 5 and pins 1 through 4.
Resistance between pin 5 and pins 1 through 4 should be approximately 46 for all. (If the result is 0
or, then replace the coil.)
Connect a clamp meter to 1 of the 2 crankcase heater wires and measure the current. The current is
normal if the result is 0.15 A or higher.
(As a guide, the current should be 0.14 A (180 V) – 0.17 A (220 V).)
Test Pin
When the test pin on the outdoor unit main control PCB is short-circuited, each part can be operated individually.
After turning OFF the outdoor unit power, short circuit the test pin (CN-TEST, black), then turn the power back ON.
The following operations will start after turning ON the outdoor unit power when the test pin (CN-TEST, black) is
short-circuited.
Set DC fan motor at W5 (FM1 : 340 – 360 rpm, FM2 : 360 – 380 rpm).
20S turns ON for 0.5 sec.
Check Inter-unit control wiring circuit.
If normal state, go to the next step. If not, it stops after LED1 starts blinking at 0.5 sec intervals and LED2
turns off.
Connector CH1 turns ON for 0.5 sec.
Do the test to read / write EEPROM.
If normal state, go to the next step. If not, it stops after LED1 starts blinking at 0.5 sec intervals and LED2
lights.
Connector O
2
turns ON for 0.5 sec.
Check inter-outdoor unit control wiring circuit to outdoor unit maintenance remote controller.
If normal state, go to the next step. If not, it stops after LED1 turns off and LED2 starts blinking at 0.5 sec
intervals.
LED1 turns ON for 0.5 sec.
Do the test(1) of circuit for writing micro-computing software.
If normal state, go to the next step. If not, it stops after LED1 starts blinking and LED2 starts blinking at 0.5
sec intervals.
LED2 turns ON for 0.5 sec.
Do the test(2) of circuit for writing micro-computing software.
If normal state, go to the next step. If not, it stops after LED1 starts blinking and LED2 starts blinking at 0.5
sec intervals.
Outputs listed below turn ON for 0.5 sec.
No.
1
2
3
4
5
Contents of output
MOV1 – A
MOV1 – B
MOV1 – / A
MOV1 – / B
SM830195-00.indb 52
2011/09/30 15:41:52
SM830209-00̲Mini̲VRF SYS.indb 51
SM830209-00̲Mini̲VRF SYS.indb 51
2012/01/11 18:26:02
2012/01/11 18:26:02
