Coil Piping and Connections
UNT-SVX07E-EN
57
flexible plastic tube over the nipple and secure with a
field supplied hose clamp.
Note:
The installer is responsible for adequately
insulating field piping. See
“External Insulating
Requirements,” page 58
for more information.
Condensate Overflow Detection Device
The condensate overflow detection device is an option on
fan-coil units with either a Tracer ZN010, ZN510, ZN520,
UC400, or the customer-supplied control interface. The
float switch, mounting bracket, and coiled leads ship
attached inside the piping end pocket of the unit. Install the
switch by placing the hole or slot in the bracket over the
condensate overflow drain (of the auxiliary drain pan) with
the switch float extending over the pan. Secure the drain
pan by attaching the pan’s bracket with the factory
provided clip. See
Figure 26
and
Figure 27
.
Automatic Changeover Sensor
Two-pipe changeover units with either the Tracer ZN010,
ZN510, ZN520, and UC400 and CSTI controls have an
automatic changeover sensor that determines heating or
cooling mode based on the supply water temperature. On
units with a factory piping package, the factory straps the
changeover sensor to the piping supply water pipe. See
Figure 28, p. 57
and
Figure 29, p. 57
.
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
changeover 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
changeover sensor upstream of the valve on the supply
water pipe. When using field supplied two-way control
valves, install the changeover sensor in a location that will
detect active water temperature. The unit must always be
Figure 26.
Condensate float switch installed in
horizontal auxiliary drain pan
Figure 27.
Condensate float switch installed in vertical
auxiliary drain pan
Figure 28.
Attach the changeover sensor to the entering
water pipe as shown for changeover to work
properly
Figure 29.
Close-up view of the changeover sensor
