Piping Installation Procedures; Refrigerant Sensors - Trane RTAA-70 Installation & Maintenance Manual

Installation — Remote Evaporator

Piping Installation Procedures

The outdoor unit and the evaporator are shipped with a 25 psig holding
pressure of dry nitrogen. Do not relieve this pressure until field installation of
the refrigerant piping is to be accomplished. This will require the removal of
the temporary pipe caps.
NOTE: Use Type L refrigerant-grade copper tubing only.
The refrigerant lines must be isolated to prevent line vibration from being
transferred to the building. Do not secure the lines rigidly to the building at
any point.
All horizontal suction lines should be pitched downward, in the direction of
flow, at a slope of 1/2 in. per 10 feet of run. This allows for larger line size,
which will improve unit efficiency.
Important: Relieve nitrogen pressure before removing end caps.
Do not use a saw to remove end caps, as this may allow copper chips to
contaminate the system. Use a tubing cutter or heat to remove the end caps.
WARNING
Prevent Injury!
When sweating line connections, always provide a sufficient
purge of dry nitrogen through the tubing to prevent the formation
of oxides/scaling cause by high temperature from brazing. Use a
pressure regulator in the line between the unit and the high
pressure nitrogen cylinder to avoid over pressurization and
possible explosion. If any refrigerant or refrigerant vapors are
present a thorough purge with dry nitrogen will prevent the
possible formation of toxic phosgene gas. Failure to follow these
recommendations could result in death or serious injury.

Refrigerant Sensors

The suction line refrigerant sensors must be installed by the contractor
installing the refrigerant piping. The sensors are prewired and each is
"wire-tied" to its respective liquid line. Fittings and adapters for mounting of
the sensors are located in the remote evaporator terminal box. See
Figure 24 for mounting instructions.
44 RTAA-SVX01A-EN