Inspection And Pipe Insulation; Air Tight Test/Vacuum Drying - Daikin LRYEQ16AY1 Service Manual

SiBE811001EB
5.5

Inspection and Pipe Insulation

For piping work contractor, electrical work contractor, and trial run workers

5.5.1 Air Tight Test/Vacuum Drying

Refrigerant is enclosed in the unit.
Be sure to keep both liquid and gas stop valves closed at the time of an air tight test or
vacuum drying of the local piping.
[For piping work contractor]
On completion of piping work, make the following inspection precisely.
∗1 The design pressure of the indoor unit (locally procured) needs to be 2.5 MPa or more.
∗2 Refer to the instruction label on the front panel of the outdoor unit (below) for the position of
CONVENI-PACK
Never open the stop 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 stop valve opened.
On completion of inspection and refrigerant charging, open the stop valve. The compressor
will malfunction if the CONVENI-PACK is operated with the stop valve closed.
To ensure that the CONVENI-PACK withstand pressure properly and prevent the
penetration of foreign substances, be sure to use R-410A-dedicated tools.
Gauge manifold
Charge hose
Vacuum pump
Gas for air tight test use
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
Operate the vacuum pump for more than 3 hours from the service port of both the liquid pipe
and the gas pipe (∗2) to evacuate to -100.7 kPa or less. After that, (1) pressurize the outdoor
unit with nitrogen gas to 0.2 MPa or more, and after leaving the outdoor unit for 10 minutes,
(2) operate the vacuum pump for more than 1 hour to evacuate to -100.7 kPa or less.
(Repeat the steps (1) and (2) 3 or more times.)
After the operations are completed, leave the outdoor unit for 1 hour and then check that the
reading on the vacuum gauge is not rising. (If the reading on the vacuum gauge is rising,
water may be remaining in the system or leakage may be occurring. In that case, perform
necessary repair and then conduct the air tight test again.)
Contact the manufacturer in advance for information on the design pressure.
the service port.
To ensure that the CONVENI-PACK withstand pressure properly and
prevent the penetration of foreign substances (water, dirt, and dust),
use an R-410A-dedicated gage manifold and charge hose. R-410A-
dedicated tools and R-407C-dedicated tools are different in screw
specification.
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).
Nitrogen gas
Position of instruction label
Label
Test Operation
64