Service manual

13-14
TROUBLESHOOTING
SM CINCO 1-A.1 GB
13.5.12 Checking High Pressure Switch (HPS)
Disconnect HPS connector from the main board and check resistance between the 2 pins of the HPS connector – if 1)
shorted the HPS is OK, otherwise replace HPS.
Replacing HPS - (14.1.10)
13.5.13 Checking Low Pressure Switch (LPS)
Disconnect LPS connector from the main board and check resistance between the 2 pins of the HPS connector – if 1)
shorted the LPS is OK otherwise replace LPS.
Replacing LPS - (14.1.10.)
13.5.14 Checking Compressor Driver Communications
Disconnect the wire cable from the connectors on both sides (driver and main board), check the wiring continuity – 1)
Repair or replace wiring if needed.
Turn power ON and check if the red led in the driver is lighted. If OK and still no communications, replace main board. 2)
If the led is OFF, replace driver.
Replacing Outdoor Unit main board - (14.1.13.)
Replacing driver - (14.1.15)
13.5.15 Checking Indoor-Outdoor Unit Communications
Disconnect the wire cable from the connectors on both sides (main board and terminal block), check the wiring continuity 1)
– Repair or replace wiring if needed.
Check the continuity of the connecting wiring between indoor and outdoor units – Repair or replace wiring if needed.2)
Problem could be either in outdoor unit main board or indoor unit controller. To verify which the faulty one is, use 3)
additional boards and replace the one which is faulty.
Replacing Outdoor Unit main board - (14.1.13.)
13.5.16 Checking Indoor Unit Fuse on Controller
If the 3.15A fuse on the main Board is burnt check the fan or any other peripheral that can cause a short:
In case of a problematic peripheral - replace it. 1)
In case no problematic peripheral replace the burnt fuse.2)
In case of frequent burning fuse, replace the controller.3)
13.5.17 Checking Indoor Unit Fan Motor
Check the motor wiring from the controller.1)
Check the motor capacitor for capacitance according to the capacitor name plate.2)
Check the resistance between each coil of the motor to be within normal range (30-3003) ).
Check resistance between each wire to ground to be above 54) .
13.5.18 Checking for electromagnetic interference (EMC problems)
13.5.18.1 EMC interference to the A/C unit
Locations most susceptible to interference
Locations near broadcast stations where there are strong electromagnetic waves.1)
Locations near amateur radio (short wave) stations.2)
Locations near electronic sewing machines and arc-welding machines.3)
Problem:
The unit may stop suddenly during operation.1)
Indicator lamps may flicker2)
Correction Actions:
The fundamental concept is to make the system less susceptible to noise by Insulation for noise or distance from the noise
source.
Use shielded wires.1)
Move unit away from the noise source.2)