Trane UniTrane Fan-Coil, Installation Operation & Maintenance

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Controls
UNT-PRC001-EN 38
Control Valve
Two-Position Fresh Air Damper Actuator
Low Temperature Detection Device
Condensate Overflow Detection Device
Economizer Fresh Air Damper Actuator
Economizer Fresh Air Damper Actuator
(ZN.520)
Model Number Digit 13 = G, H, or J
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 econo-
mizer operation stops or if the unit is in
the heating mode, the fresh air damper
adjusts to its minimum position.
Note: The Trane Company 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 tempera-
ture of 36 F to the hydronic coil, the
normally-closed switch opens a corre-
sponding set of binary input terminals.
The fan disables, control valves open,
and the fresh air damper closes.
Thirty minutes after the diagnostic,
Tracer ZN.010, ZN.510, or ZN.520 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
ZN.510 or ZN.520 controller you can reset
using Summit. Use Rover service
software to reset units with ZN.010,
ZN.510, or ZN.520.