External Insulating Requirements - Trane UniTrane Installation, Operation And Maintenance Manual

Coil Piping and Connections
Figure 31. Close-up view of the entering water
temperature sensor
If the unit does not have a factory piping package, the
factory attaches the sensor and coiled lead wires to the
piping side end panel. The installer should attach the
sensor parallel to and in direct contact with the supply
water pipe.
Note: The installer is responsible to ensure the entering
water temperature sensor is installed in a location
that can sense active water temperature.
Otherwise, the unit may fail to sense the correct
operating mode and disable temperature control.
When using field supplied three-way valves, install the
entering water temperature sensor upstream of the valve
on the supply water pipe. When using field supplied two-
way control valves, install the entering water temperature
sensor in a location that will detect active water
temperature. The unit must always be able to sense the
correct system water temperature, regardless of the
control valve position.
Note: The maximum length of the automatic changeover
wire cannot exceed ten feet from the control panel.
If the sensor extends beyond the unit chassis, use
shielded conductors to eliminate radio frequency
interference (RFI).
Venting the Hydronic Coil
The hydronic coil contains a vent, either manual or
automatic, to release air from the unit. This vent is not
sufficient for venting the water piping system in the
building.
The coil air vent is on the piping side, above the coil
connections on the unit. See the figures below. Perform
the following steps to vent the coil after installing the unit.
56
Figure 32. Manual coil air vent with set screw
Figure 33. Manual coil air vent with Shrader fitting
1. Pressurize the building piping system with water and
vent any trapped air at system vents.
2. For units with manual air vents, back the set screw out
to expel air from the unit and then re-tighten the set
screw.
The automatic air vent should require no adjustment for
the coil to vent. However, if the coil does not vent
immediately, unscrew the outer portion of the fitting to
expel air from the port.
If debris has become trapped in the vent, completely
remove the outer portion of the fitting and clean.

External Insulating Requirements

Insulate and vapor seal surfaces colder than surrounding
air dew-point a to prevent unplanned condensation. Trane
recommends field-insulation of the following areas to
prevent potential condensate problems:
UNT-SVX07J-EN