Airtight Test - Toshiba Carrier MCY-MAP0367HS-UL Manuel D'installation

In case of an Outside Air Unit connection
• The combination which can connect Outside Air Unit is only the 1:1 combination of MCY-MAP0487HS-UL and
MMD-AP0481HF2UL.
Other combination is not permitted.
Height difference between
Main
an outside air unit and an
pipe
H3
outdoor unit
L4
Total extension of pipe (liquid pipe, real length)
Furthest piping length
(=Max.length of main pipe)
Piping Length
Max equivalent length of furthest piping from 1st branching Li
Max real length of indoor unit connecting pipe
Height between indoor and
Height
outdoor units H3
Difference
Height between indoor units H2
 Airtight test
Before starting an airtight test, tighten the spindle valves further on the gas side and liquid side.
Pressurize the pipe with nitrogen gas charged from the service port to the design pressure to conduct the airtight test.
After the airtight test is completed, evacuate the nitrogen gas.
• Apply pressure from the service ports of the packed valves (or ball valves) at the liquid side and gas side.
• An air tight test can be only performed to the service ports at the liquid side and gas side of the outdoor unit.
• Fully close the valves at the liquid side and gas side. There is a possibility that nitrogen gas may enter the
refrigerant cycle, re-tighten the valve rods before applying pressure.
(Re-tightening of the valve rods are unnecessary for valves at the gas side because they are ball valves.)
• For each refrigerant line, apply pressure gradually with the following steps at the liquid side and gas side.
Apply pressure to the gas side and liquid side.
EN-21
Outdoor unit
Outside air unit
Allowable value
(ft (m))
328 (100)
Real length 328 (100)
Equivalent length 410 (125)
—
—
Upper outdoor unit 164 (50)
Lower outdoor unit 9 (3)
—
– 11 –
REQUIREMENT
Do not use "Oxygen", "Flammable gas" and "Noxious gas" in an airtight test.
Connected to indoor unit
Main pipe
Pipes
L4
To detect a gross leakage
L4
1. Apply pressure 44 psi for 3 minutes or more.
2. Apply pressure 218 psi for 3 minutes or more.
To detect a slow leakage
3. Apply pressure 602 psi for approx. 24 hours.
• Check pressure down.
No pressure down: Accepted
Pressure down: Check the leaked position.
NOTE
If the environmental temperature changes from the moment pressure is applied to 24 hours after that, the pressure
will change by about 1.45 psi per 1.8 °F (1 °C). Consider the pressure change when checking the test result.
REQUIREMENT
When a 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.
Low pressure
gauge
Ball valve fully closed
(Gas side)
Outdoor unit
Flare connection
Ø1/4" (6.4 mm)
Service
Copper pipe
port
Flare connection
Ø1/4" (6.4 mm)
Copper pipe
Service port
Packed valve fully closed
(Liquid side)
High pressure
gauge
Gauge
manifold
Reducing
valve
Nitrogen gas
EN-22