A Netcol5000 A025 preparatory work strictly according to the user manual but when first time start the air conditioner and run less than 1 minutes it appears compressor HO switch alarm , shutdown and power off can't eliminate alarm , after a period of time appeared alarm ( HP switch locked )
compressor HP switch locked
compressor HP switch alarm
1- As long as in diagonistic mode when compressor started , the outdoor machine rinning normally so we can exclude the outdoor unit input power lack of phase , phase error , outdoor unit switch line fault.
2- Distance between the new outdoors unti i2 1200mm and supporting feet height is 350mm , and it can meet the operation requirements of outdoor unit , so installation is not reasonable , the outdoor fan is damaged.
3- Refrigerant charging strrictly according to the manual formula calculation , it should not be the reason of charging too much refrigerant.
4- After the air condition shut down , check the exhaust pressure is 1.5Mpa but the compressor discharge HP switch trigger alarm at 4.25Mpa. eliminate alarm at 3.6Mpa.
5- Normally the HP switch is closed , when alarms it's disconnect signal , we pull out the two terminals wires of HP switch and short circuit these two wires, found the HP switch alarm is eliminated ; disconnect two terminals high-voltage switch alarm appeared again, it's shown that the HP alarm is not abnormal & at the same time use a multi-meter measured the two terminals of the HP switch .
The on-off state is off , indicating the HP switch state is normal.
6- Replace the HP switch and then restart commissioing , then A/C operation is normal.
Replacing the HP switch
Since the HP switch has sealant it is a must to pay attention to the removal of original HP switch.