Trane UV-SVN02B-EN, Installation Operation & Maintenance, Page: 26 / 52

26 UV-SVN002-EN
Installation
Split System Units
The following refrigerant piping and
interconnecting wiring instructions
apply to unit ventilators with direct
expansion type cooling coils used in
conjunction with air-cooled condensing
units. Reference must also be made to
the condensing unit installation and
wiring manuals which are shipped with
the condensing unit.
NOTE: A UL listing mark applied to a
unit ventilator does not apply to any
associated refrigerant condensing unit.
Refrigerant Piping
Unit ventilators with direct expansion
cooling contain a nitrogen holding
charge in the evaporator coils.
Connections are ‘‘pinched off’’ at the
factory.
To connect the condensing unit lines,
cut off the stubouts and swage. The
condensing unit lines can then be
brought into the swage and brazed.
Trane recommends the use of nitrogen
purge when brazing refrigerant lines to
prevent formation of oxides in the
lines.
Install the refrigerant suction and liquid
lines as described in the condensing
unit installation instructions. The TXV is
factory installed on the Unit Ventilator.
Piping should be run straight out
through the back of the unit. Access
piping knockouts are located in the rear
panels of the unit, as shown in
Figures
6 through 14.
Recommended refrigerant line connec-
tions for various unit combinations are
given in
Table 10 . Typical Superheat
Charging Charts are shown in the Trane
Service Facts found in the condensing
unit section manual. Refrigerant charge
weights can also be determined with
your local Trane sales engineer using a
valid Trane Selection Program.
Unit
Size
Condensing Unit UV Connection Size
Condensing Unit
Connection Size
Liquid Line Size Suction Line Size
075 TTB, TTP
Liquid - 3/8”
Suction - 7/8”
Liquid - 3/8”
Suction - 7/8”
3/8” OD 7/8” OD
100 TTP, TTB, TTA, 2TTA
Liquid - 3/8”
Suction - 7/8”
Liquid - 3/8”
Suction - 7/8”
3/8” OD 7/8” OD
125 TTB, TTA, 2TTA
Liquid - 3/8”
Suction - 7/8”
Liquid - 3/8”
Suction - 7/8”
3/8” OD 7/8” OD
150 2TTA, TTB, TTA
Liquid - 3/8”
Suction - 7/8”
Liquid - 3/8”
Suction - 7/8”
3/8” OD 7/8” OD
200 TTA, 2TTA
Liquid - 3/8”
Suction - 7/8”
Liquid - 3/8”
Suction - 7/8”
3/8” OD 7/8” OD
Table 10: Refrigerant Line Sizes (TTB, TTA, 2TTA & TTP Condensing Units)
Notes:
1. Refrigerant connections sweat and “pinched-off” at the factory
2. All DX Unit Ventilators are shipped with a Nitrogen holding charge.