Idiomas disponibles
Idiomas disponibles
(*1) : (C) is outdoor unit furthest from the 1st branch and (N) is the indoor unit furthest from the 1st branch.
(*2) : The total amount of refrigerant in the system should be 308 lbs (140 kg) or less.
(*3) : When using a Multi port tyape Flow Selector unit, be sure to set the piping length between the indoor and the Flow
Selector unit at least 33 ft (10 m).
If a piping length of 33 ft (10 m) or longer is not secured, refrigerant noise generated from the Multi port type Flow
Selector unit may propagate to the indoor unit.
(*4) : Extension up till 295 ft (90 m) is possible with conditions below :
- Single outdoor unit system
- Connected ratio of indoor units to outdoor units is below 105%
- Liquid side has been increased 1 size from standard size
- Change the connection method of the indoor unit from flare connection to welding connection.
(*5) : Connection ratio of indoor unit capacity code to outdoor unit capacity code.
(*6) : This limitation is for systems with three outdoor units connected.
31-EN
Airtightness test
After the refrigerant piping has been finished, execute an airtight test.
For an airtight test, connect a nitrogen gas canister as shown in the figure on this page and apply pressure.
Be sure to apply pressure from the service ports of the packed valves (or ball valve) at the liquid side and
(HP/LP, Suction) gas side.
An airtight test can only be performed at the service ports at the liquid side and (HP/LP, Suction) gas side.
Close the valves fully at the (HP/LP, Suction) gas side and liquid side. As there is a possibility that the nitrogen
gas will enter into the cycle of outdoor units, re-tighten the valve rods at the liquid side before applying pressure.
For each refrigerant line, apply pressure gradually in steps at the liquid side and (HP/LP, Suction) gas side.
Be sure to apply pressure at the (HP/LP, Suction) gas side and liquid side.
WARNING
Never use oxygen, flammable gases, or noxious gases in an airtight test.
To gauge
manifold
Liquid-side
service port
Service
port of HP/
To outdoor unit
Liquid-side
LP gas
valve
side
To outdoor
unit
To
outdoor
Piping at site
HP/LP
unit
gas side
valve
Piping at site
Service port of suction gas side
Ball valve of suction gas side
Able to detect a serious leakage
1. Apply pressure 43.5 psi (0.3 MPa) for 5 minutes or more.
2. Apply pressure 217.5 psi (1.5 MPa) for 5 minutes or more.
Available to detect slow leakage
3. Apply pressure 601 psi (4.15 MPa) for approx. 24 hours.
If there is no pressure decrease after 24 hours, the test is passed.
NOTE
However, if the environmental temperature changes from the moment of applying pressure to 24 hours after that,
the pressure will change by about 1.45 psi (0.01 MPa) per 1.8°F. Consider the pressure change when checking
the test result.
REQUIREMENT
When pressure decrease is detected in steps 1-3, check the leakage at the connecting points.
Check the leakage using a foaming agent or other measures and seal the leak with re-brazing, flare retightening
or other methods. After sealing, execute an airtight test again.
– 16 –
Low pressure
Valve details
Connected to
Suction gas side valve
indoor unit
fully closed
Main
piping
Header outdoor unit
Brazed
Service port
copper pipe
Brazed
Service port
HP/LP gas side valve fully
closed
Brazed
Service port
Liquid side valve fully
Piping at site
closed
High pressure
gauge
gauge
Gauge
V
V
L
H
manifold
Reducing
valve
copper
pipe
Nitrogen
gas
EN
EN
ID
32-EN
