Trane 4MYW4509A1 Installation Manual page 14

Installation
Vacuum Pump and Leak Testing
¡Hazard of Explosion!
Never use an open flame to detect gas leaks. Explosive conditions may occur. Use a leak test
solution or other approved methods for leak testing. Failure to follow recommended safe leak
test procedures could result in death or serious injury or equipment or property-only damage.
¡Hazard of Explosion!
Use only dry nitrogen with a pressure regulator for pressurizing unit. Do not use acetylene,
oxygen or compressed air or mixtures containing them for pressure testing. Do not use
mixtures of a hydrogen containing refrigerant and air above atmospheric pressure for
pressure testing as they may become flammable and could result in an explosion. Refrigerant,
when used as a trace gas, should only be mixed with dry nitrogen for pressurizing units.
Failure to follow these recommendations could result in death or serious injury or equipment
or property-only damage.
After the installation of refrigerant lines to both the outdoor and indoor units are completed, the
flare connections must be checked for leaks. Through the service valve ports, pressurize the indoor
unit and field refrigerant lines with dry nitrogen to 350-400 psi. Use soap bubbles or other leak-
checking methods to see that all flares are leak free. If not, release pressure; then repair.
System Evacuation
Note: Since the outdoor unit has a refrigerant charge, the gas and liquid line valves must remain
1. Upon completion of leak check, evacuate the refrigerant lines and indoor coil before opening
2. Attach appropriate hoses from manifold gauge to gas and liquid line pressure taps.
3. Attach center hose of manifold gauge to vacuum pump.
4. Evacuate until the micron gauge reads no higher than 250 microns.
5. Close off valve to vacuum pump and observe the micron gauge. If gauge pressure rises above
6. If vacuum gauge does not rise above 500 microns in one (1) minute, the evacuation should be
7. Blank off vacuum pump and micron gauge and close vales on manifold gauge set.
Note: DO NOT VENT REFRIGERANT INTO THE ATMOSPHERE.
8. The liquid line shut-off valve can now be opened. Remove shut-off valve cap. Fully insert hex
14
closed.
the gas and liquid line valves.
500 microns in one minute (1) then evacuation is incomplete or system has a leak.
complete.
wrench into the stem and back-out counterclockwise open.
WARNING
WARNING
MS-SVN046A-EN