To Detect A Gross Leakage; To Detect A Slow Leakage - Toshiba Carrier MCY-MAP0367HS-UL Installation Manual

 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.
REQUIREMENT
Do not use "Oxygen", "Flammable gas" and "Noxious gas" in an airtight test.
Connected to indoor unit
Main pipe
Flare connection
Flare connection

To detect a gross leakage

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.
EN-21
Low pressure High pressure
gauge gauge
Ball valve fully closed
(Gas side)
Gauge
Outdoor unit manifold
Reducing
valve
Ø1/4" (6.4 mm)
Service
Copper pipe
port
Ø1/4" (6.4 mm)
Copper pipe
Service port
Packed valve fully closed
Nitrogen gas
(Liquid side)
– 11 –
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.
Installation Manual
EN-22