Service Manual

SiUS281811E Servicing Items to be Confirmed
Part 6 Service Diagnosis 167
(4) Precautions for piping work and refrigerant charging:
This unit uses R-410A refrigerant. Pay attention to the following conditions.
1. The charging pipe and the manifold tube use R-410A products for pressure maintenance and
avoiding contamination by impurities (SUNISO oil, etc.).
2. Be sure to purge with nitrogen when brazing.
 Properly perform airtightness test and vacuum drying. (Airtight test pressure: 4.0 MPa (580
psi))
 Charge refrigerant in liquid state.
(5) Precautions for operating in servicing mode (field setting):
When a test operation is interrupted or after exiting service mode, please wait for at least one
minute before entering service mode again. In case of continuous execution, the outdoor unit PCB
may sometimes display an error code. If any error codes are displayed, press the RETURN (BS3)
button. If performing the above operation still does not eliminate the error, reconnect the unit to the
power supply.