Low Voltage Wiring; Emergency Stop; External Auto/Stop; Ice Building Option - Trane Sintesis RTAF Installation, Operation And Maintenance Manual

Installation Electrical

Low Voltage Wiring

The remote devices described below require low voltage
wiring. All wiring to and from these remote input devices
to the Control Panel must be made with shielded, twisted
pair conductors. Be sure to ground the shielding only at
the panel.
Important: To prevent control malfunctions, do not run
low voltage wiring (<30 V) in conduit with
conductors carrying more than 30 volts.

Emergency Stop

UC800 provides auxiliary control for a customer specified/
installed latching trip out. When this customer-furnished
remote contact 6S2 is provided, the chiller will run
normally when the contact is closed. When the contact
opens, the unit will trip on a manually resettable
diagnostic.This condition requires manual reset at the
front of the control panel.
Connect low voltage leads to terminal strip locations on
1K2. Refer to the field diagrams that are shipped with the
unit.
Silver or gold-plated contacts are recommended.These
customer-furnished contacts must be compatible with 24
VDC, 12 mA resistive load.

External Auto/Stop

If the unit requires the external Auto/Stop function, the
installer must provide remote contact 6S1.
The chiller will run normally when the contacts are closed.
When either contact opens, the compressor(s), if
operating, will go to the RUN:UNLOAD operating mode
and cycle off. Unit operation will be inhibited. Closure of
the contacts will permit the unit to return to normal
operation.
Field-supplied contacts for all low voltage connections
must be compatible with dry circuit 24 VDC for a 12 mA
resistive load. Refer to the field diagrams that are shipped
with the unit.

Ice Building Option

UC800 provides auxiliary control for a customer specified/
installed contact closure for ice building if so configured
and enabled.This output is known as the Ice Building
Status Relay.The normally open contact will be closed
when ice building is in progress and open when ice
building has been normally terminated either through Ice
Termination setpoint being reached or removal of the Ice
Building command.This output is for use with the ice
storage system equipment or controls (provided by
others) to signal the system changes required as the chiller
mode changes from "ice building" to "ice complete" .
When contact 5K3 is provided, the chiller will run normally
when the contact is open.
UC800 will accept either an isolated contact closure
(External Ice Building command) or a Remote
28
Communicated input (Tracer) to initiate and command the
Ice Building mode.
UC800 also provides a "Front Panel IceTermination
Setpoint" , settable throughTracer™TU, and adjustable
from 20 to 31°F (-6.7 to -0.5°C) in at least 1°F (1°C)
increments.
Note: When in the Ice Building mode, and the evaporator
entering water temperature drops below the ice
termination setpoint, the chiller terminates the Ice
Building mode and changes to the Ice Building
Complete Mode.
NOTICE:
Equipment Damage!
Freeze inhibitor must be adequate for the leaving water
temperature. Failure to do so will result in damage to
system components.
Tracer™TU must also be used to enable or disable Ice
Machine Control.This setting does not prevent theTracer
from commanding Ice Building mode.
Upon contact closure, the UC800 will initiate an ice
building mode, in which the unit runs fully loaded at all
times. Ice building shall be terminated either by opening
the contact or based on the entering evaporator water
temperature. UC800 will not permit the ice building mode
to be reentered until the unit has been switched out of ice
building mode (open 5K3 contacts) and then switched back
into ice building mode (close 5K3 contacts.)
In ice building, all limits (freeze avoidance, evaporator,
condenser, current) will be ignored. All safeties will be
enforced.
If, while in ice building mode, the unit gets down to the
freeze stat setting (water or refrigerant), the unit will shut
down on a manually resettable diagnostic, just as in
normal operation.
Connect leads from 5K3 to the proper terminals of 1K22.
See the field diagrams which are shipped with the unit.
Silver or gold-plated contacts are recommended.These
customer furnished contacts must be compatible with 24
VDC, 12 mA resistive load.
External Chilled Water Setpoint (ECWS)
Option
The UC800 provides inputs that accept either 4-20 mA or
2-10 VDC signals to set the external chilled water setpoint
(ECWS).This is not a reset function.The input defines the
setpoint.This input is primarily used with generic BAS
(building automation systems).The chilled water setpoint
is set via theTracer AdaptiView™TD7 or through digital
communication withTracer (Comm3).
The chilled water setpoint may be changed from a remote
location by sending either a 2-10 VDC or 4-20 mA signal to
the 1K24, terminals 5 and 6 LLID.The 2-10 VDC and 4-20
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