Refrigerant Charging Procedures - Trane TR-SCS Series Installation, Operation And Maintenance Manual

newly installed or existing piping. It is essential to
use a well-maintained pump that is in good
operating condition. Always ensure it contains
clean, fresh oil. Change the oil in the pump every 20
minutes to maintain its ability to remove moisture.
Note: Use high quality hoses ensuring they are free of
defects and don't leak. It is recommended to use
copper tubing instead of hoses if possible due to
the low vacuum that must be attained when
evacuating the system. The use of short, large
diameter hoses helps reduce evacuation time.
3. After ensuring there are no leaks, relieve pressure and
evacuate the entire system while maintaining all the
solenoids and hot gas reheat valves open. Pull an
initial vacuum of 1500 microns or lower using the
suction and discharge service ports and the service
port of the receiver (if applicable).
Note: When pulling a vacuum, the Schrader valves will
unnecessarily restrict the openings, increasing the
evacuation time. During the evacuation process it
is recommended to remove the Schrader valve
cores with a Schrader valve removal tool and draw
the vacuum through the port on the removal tool.
4. If you cannot evacuate the system below 1500
microns, close the vacuum pump isolation valve and
perform a rateof-rise test by observing the standing
pressure overtime. If the pressure rises slowly (up to
200 microns in 15 minutes) it indicates moisture is in
the system that still needs to be boiled off. Proceed to
step #5. If the pressure rises rapidly up to atmospheric
pressure (more than 50 microns per minute) it
indicates a leak that wasn't detected during step #2. In
this case troubleshoot the entire system for leaks and
repair them. Then begin the initial evacuation process
again starting at step #3.
5. If no leaks are detected after the initial vacuum, release
the vacuum and pressurize the system with 2-3 lb of
dry nitrogen. Allow the system to stand for two hours
with the dry nitrogen charge. This gives time for the
nitrogen molecules to disperse in the system
absorbing moisture.
6. After two hours, release the pressure. Then turn on the
vacuum pump and evacuate the system a second time
down to 1500 microns or less. Close the vacuum pump
isolation valve and pressurize the system again with
dry nitrogen and allow the system to stand for two
hours as in step #5.
7. After two hours release the pressure. Turn on the
vacuum pump and complete the process of evacuating
the system, this time with a goal of achieving a 250-
micron vacuum or less. Close the vacuum pump
isolation valve. When you can hold the vacuum at 500
microns or lower for at least 2 hours with no significant
rise in pressure, the system is ready to charge.
8. Replace the Schrader valve cores if you removed them
during the evacuation steps. You may now introduce
the refrigerant charge through the Schrader valves.
SS-SVX006C-EN

Refrigerant Charging Procedures

R407C and R410A refrigerant must be weighed in when
performing the charge. Ensure an adequate supply of
refrigerant is available before beginning. Calculate the
minimum amount of refrigerant needed for your system.
When charging a system using a blended refrigerant, it is
essential that the composition of the refrigerant is
maintained. To ensure correct composition, introduce the
refrigerant (R407C or R410A) into the system in liquid form
rather than vapor form. Cylinders which are not provided
with dip tubes should be inverted to allow only liquid
refrigerant to charge the system. Keeping the temperature
of the cylinder below 85°F will help to maintain the correct
refrigerant composition while the cylinder is emptied.
NOTICE
Equipment Damage!
POE oil is used in systems with R407C or R410A
refrigerant. POE oil quickly absorbs moisture when
exposed to air. High POE oil moisture levels react with
refrigerant to form acid which results in system
contamination. Keep the entire system sealed as much
as possible and minimize exposure of the POE oil to
outside air.
Note: Refrigerant charging must be performed by a
qualified air conditioning technician. Trane
recommends using the services of our Field
Service Department to assist in start-up and
commissioning. We have assembled a highly
qualified team of experienced industry
professionals who provide expert start-up services
anywhere in the world.
They will ensure your equipment is correctly installed and
is operating properly. This will help to ensure your unit
provides years of trouble-free service while operating at
its highest efficiency. They will also enter the necessary
Information for you on the Warranty Registration and
Start-up Checklist and ensure it is filed with Trane for your
warranty protection.
WARNING
Confined Space Hazards!
Failure to follow instructions below could result in
death or serious injury.
Do not work in confined spaces where refrigerant or
other hazardous, toxic or flammable gas may be
leaking. Refrigerant or other gases could displace
available oxygen to breathe, causing possible
asphyxiation or other serious health risks. Some gases
may be flammable and or explosive. If a leak in such
spaces is detected, evacuate the area immediately and
contact the proper rescue or response authority.
Initial System Charge
Follow the step by step instructions below to charge
systems using R407C and R410A refrigerant. The initial
Installation
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