Toshiba MMY-SUG0801MT8P-E Installation Manual page 40

System restriction
Outdoor unit combination
Max. capacity of outdoor units
Indoor unit connection
Total capacity of indoor units (Varies depending on the height difference
between indoor units.)
(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
Total extension of pipe
(Liquid pipe, real length)
Farthest piping length L
Pipe length
Max.equivalent length of Main piping L1
Equivalent length of farthest piping from 1 st branching Li
Max. real length of indoor unit connecting piping
Max. equivalent length between branches
Height difference between
Difference
outdoor and indoor unit H1
in height
Height difference between indoor units H2
(*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 flare connection to welding connection.
(*3): For installation conditions, refer to the precautions of equipment using R32.
77-EN
Only 1 unit
Up to 24 HP
Up to 54 units
H2 [ 15 m 200% of outdoor units capacity(*1)
H2 > 15 m 105% of outdoor units capacity
Allowable
Piping section
Value
L1 + L2 + L3 + L4 + L5 + L6 +
500 m (*1) L7 + a + b + c + d + e + f + g
+ h + i + j
Equivalent length 215 m
L1 + L3 + L4 + L5 + L6 + j
Real length 190 m
Equivalent length 125 m
L1
Real length 100 m
H1 > 3 m 65 m
L3 + L4 + L5 + L6 + j
H1 [ 3 m 90 m
50 m a, b, c, d, e, f, g, h, i, j
50 m L2, L3, L4, L5, L6, L7
H2 > 3 m 50 m
Upper outdoor unit
70 m
H2 [ 3 m
90 m (*2)
Lower outdoor unit 40 m
40 m
– 39 –
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.
For Heat Recovery System Installation
To gauge
manifold
Liquid-side
service port
Liquid-side
valve
Piping at site
HP/LP
gas side
valve
Service port of suction gas side
Ball valve of suction gas side
-----
For Heat Pump System Installation
-----
Valve details
To gauge
manifold
Liquid-side
valve
Liquid-side
service port
Piping at site
Valve details
Connected to
indoor unit
Main
Service
piping
port of HP/
To outdoor unit
LP gas
Brazed
side
To outdoor
unit
To
outdoor
Brazed
unit
Piping at site
Brazed
Piping at site
Connected to indoor unit
Main piping
Gas-side
service port
To
outdoor
unit
To
Outdoor
unit
Gas side
Connected to other
Piping at site
valve
follower units
Low pressure High pressure
gauge gauge
Suction gas side valve
fully closed
Gauge
V V
L H
manifold
Header outdoor unit
Reducing
Service port
valve
copper pipe
Service port
copper
HP/LP gas side valve fully
pipe
closed
Nitrogen
Service port
gas
Liquid side valve fully
closed
Low pressure High pressure
gauge gauge
Gas side valve fully closed
Gauge
V V
L H
Header outdoor unit
manifold
Service port
Brazed
Reducing
Copper pipe
valve
Brazed
Copper
Service port
pipe
Liquid valve fully closed
Nitrogen
gas
78-EN