78-EN
77-EN
– 39 –
Airtightness test
After the refrigerant piping has been
fi
nished, execute an airtight test.
For an airtight test, connect a nitrogen gas canister as shown in the
fi
gure 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,
fl
ammable gases, or noxious gases in an airtight test.
V
L
V
H
To outdoor unit
Connected to
indoor unit
Main
piping
Suction gas side valve
fully closed
Low pressure
gauge
High pressure
gauge
Gauge
manifold
Reducing
valve
copper
pipe
Nitrogen
gas
Header outdoor unit
Service port
copper pipe
HP/LP gas side valve fully
closed
Liquid side valve fully
closed
Service port
Service port
Brazed
Brazed
Brazed
Piping at site
Valve details
Service port of suction gas side
Ball valve of suction gas side
HP/LP
gas side
valve
Liquid-side
service port
To gauge
manifold
Liquid-side
valve
To outdoor
unit
Piping at site
Piping at site
To
outdoor
unit
Service
port of HP/
LP gas
side
For Heat Recovery System Installation
V
L
V
H
Connected to indoor unit
Valve details
Liquid-side
valve
To
outdoor
unit
Piping at site
Piping at site
Gas side
valve
To
Outdoor
unit
Gas-side
service port
Liquid-side
service port
To gauge
manifold
Connected to other
follower units
Gas side valve fully closed
Header outdoor unit
Service port
Service port
Liquid valve fully closed
Copper
pipe
Reducing
valve
Gauge
manifold
Low pressure
gauge
High pressure
gauge
Nitrogen
gas
Copper pipe
Brazed
Brazed
Main piping
For Heat Pump System Installation
¡
System restriction
Outdoor unit combination
Only 1 unit
Max. capacity of outdoor units
Up to 24 HP
Indoor unit connection
Up to 54 units
Total capacity of indoor units (Varies depending on the height difference
between indoor units.)
H2
[
15 m 200% of outdoor units capacity(*1)
H2 > 15 m
105% of outdoor units capacity
(1*): If it exceeds 135%, there is a limit to the maximum number of indoor units that can be connected.
¡
Allowable length and allowable height difference of refrigerant piping
Item
Allowable
Value
Piping section
Pipe length
Total extension of pipe
(Liquid pipe, real length)
500 m (*1)
L1 + L2 + L3 + L4 + L5 + L6 +
L7 + a + b + c + d + e + f + g
+ h + i + j
Farthest piping length
L
Equivalent length
215 m
L1 + L3 + L4 + L5 + L6 + j
Real length
190 m
Max.equivalent length of Main piping
L1
Equivalent length
125 m
L1
Real length
100 m
Equivalent length of farthest piping from 1 st branching
Li
H1 > 3 m
65 m
L3 + L4 + L5 + L6 + j
H1
[
3 m
90 m
Max. real length of indoor unit connecting piping
50 m
a, b, c, d, e, f, g, h, i, j
Max. equivalent length between branches
50 m
L2, L3, L4, L5, L6, L7
Difference
in height
Height difference between
outdoor and indoor unit
H1
Upper outdoor unit
H2 > 3 m
50 m
-----
H2
[
3 m
70 m
90 m (*2)
Lower outdoor unit
40 m
Height difference between indoor units
H2
40 m
-----
(*1): The total amount of system refrigerant should be 63.8 kg or less.
(*2): Extension up till 90 m is possible with conditions below :
- 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
fl
are connection to welding connection.
(*3): For installation conditions, refer to the precautions of equipment using R32.
