Test Operation
SiENBE28-901
66
Air Cooled Refrigeration Condensing Unit
5.3
Inspection and Pipe Insulation
For piping work contractor, electrical work contractor, and trial run workers
Never open the shutoff valve until the insulation measurement of the main power supply
circuit is finished. The measured insulation value will become lower if the measurement is
made with the shutoff valve opened.
On completion of inspection and refrigerant charging, open the shutoff valve. The
compressor will malfunction if the condensing unit is operated with the shutoff valve closed.
5.3.1 Air tight Test/Vacuum Drying
Refrigerant is enclosed in the unit.
Be sure to keep both liquid and gas shutoff valves closed at the time of an airtight test or
vacuum drying of the local piping.
[For piping work contractor]
On completion of piping work, make the following inspection precisely.
To ensure that the condensing unit withstand pressure properly and prevent the penetration
of foreign substances, be sure to use R410A-dedicated tools.
Air tight
Pressurize the high-pressure section of the system (liquid piping) to 3.8 MPa (38 bar) and
the low-pressure section of the system (gas piping) to the design pressure (*1) of the indoor
unit (field supply) from the service port (*2) (do not exceed the design pressure). The system
is considered to have passed if there is no decrease in the pressure over a period of 24
hours.
If there is a decrease in the pressure, check for and repair leaks.
Vacuum drying
Connect a vacuum pump to the service ports (*) of both the liquid and gas pipes for at least
2 hours and vacuum the unit down to –100.7 kPa or below. Then leave the unit for at least 1
hour at a pressure of –100.7 kPa or below and check that the vacuum gage reading will not
rise. If the pressure rises, there is residual water in the system or the system has leakage.
*1 Contact the manufacturer in advance for more information about the design pressure of the
indoor unit (field supply).
*2 Refer to the instruction label on the front panel of the outdoor unit (below) for the position of
the service port.
Gauge manifold
Charge hose
To ensure that the condensing unit withstand pressure properly and
prevent the penetration of foreign substances (water, dirt, and dust),
use an R410A-dedicated gage manifold and charge hose. R410A-
dedicated tools and R407C-dedicated tools are different in screw
specification.
Vacuum pump
Pay the utmost attention so that the pump oil will not flow backward
into the system while the pump is not in operation.
Use a vacuum pump that can vacuum down to –100.7kPa (5 Torr or
–755mmHg).
Gas for airtight test use
Nitrogen gas
Position of instruction label
Label
