Catalogue

54 UNT-PRC001-EN
Controls
This option is a three-wire floating point, spring-return damper actuator and is factory-wired and
mounted to the damper assembly. When the controller enables the economizer and the unit is in
occupied mode, the fresh air damper modulates between its minimum position (editable) and the
full open position to maintain setpoint temperature. If economizer operation stops or if the unit is
in the heating mode, the fresh air damper adjusts to its minimum position.
Note: Trane highly recommends using the low temperature detection option with a fresh air
damper to detect possible freeze conditions.
Low Temperature Detection, Model Number Digit 36 = 2
When the low temperature detection device senses an entering air temperature of 36°F to the
hydronic coil, the normally-closed switch opens a corresponding set of binary input terminals. The
fan disables, control valves open, and the fresh air damper closes.
Thirty minutes after the diagnostic, Tracer ZN010, ZN510, or ZN520 uses an automatic reset
function to attempt to reset the unit. If the diagnostic occurs again within 24 hours after an
automatic diagnostic reset, the unit will require a manual reset. This function attempts to resolve
the infrequent nuisance alarm.
The low temperature detection device is an averaging type capillary tube and will reset when it
detects an entering air temperature of at least 44°F.
Condensate Overflow Detection, Model Number Digit 35 = 2
A float switch is factory-supplied for field installation in the auxiliary drain pan to detect a high
condensate water level. When the float switch rises, the normally closed input opens a
corresponding set of binary input terminals. This also causes the fan to disable, and the control
valve and fresh air damper options to close. Although the float switch will close when the high
condensate level recedes, the controller must be manually reset before normal unit operation can
occur. If using a Tracer ZN510, ZN520 or UC400 controller you can reset using Tracer Summit. Use
Rover service software to reset units with Tracer ZN010, ZN510, or ZN520 and Tracer TU for units
with a UC400.
Figure 25. Low temperature detection device
Figure 26. Condensate overflow detection device
End Device Options
UNT-PRC001-EN.book Page 54 Tuesday, May 8, 2012 10:54 AM