Low Voltage Wiring; Emergency Stop (Normal Trip); External Circuit Lockout; Ice Making Option - Trane RTAA-70 Installation & 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 UCM must be made with
shielded, twisted-pair conductors. Be sure to ground the shielding only at the
Clear Language Display. See Wiring Section for the recommended conductor
sizes.

Emergency Stop (Normal Trip)

The Clear Language Display provides auxiliary control for a customer
specified/ installed latching tripout. When this customer-furnished remote
contact (5K18) is provided, the chiller will run normally when the contact is
closed. When the contact opens, the unit will trip off on a manually resettable
diagnostic. This condition requires manual reset at the chiller switch on the
front of the Clear Language Display.
To connect, first remove the jumper located between terminals 3 and 4 of
1U1TB1 Connect low voltage leads 513 and 514 to those terminals. Refer to
the field diagrams which are shipped with the unit.
Silver or gold-plated contacts are recommended. These customer-furnished
contacts must be compatible with 12 VDC, 45 mA resistive load.
External Circuit Lockout — Circuit #1
The UCM provides for auxiliary control via a customer specified or installed
contact closure, for individual operation of Circuit #1. If the contact is closed,
the refrigerant circuit will not operate. The refrigerant circuit will run normally
when the contact is opened. This feature is used to restrict total chiller
operation, eg. during emergency generator operations.
External circuit lockout will only function if External Circuit Lockout (Service
Setting Menu) is enabled.
These customer-supplied contact closures must be compatible with 12 VDC,
45 mA resistive load. Silver or gold plated contacts are recommended.
To install, cut, strip and wire-nut existing wire loop #W7 on the P43 connector
of the 1U4 module to low voltage leads 45A and 45B. Connections are shown
in the field diagrams which are shipped with the unit.
External Circuit Lockout — Circuit #2
The UCM provides for auxiliary control via a customer specified or installed
contact closure, for individual operation of Circuit #2. If the contact is closed,
the refrigerant circuit will not operate. The refrigerant circuit will run normally
when the contact is opened. This feature is used to restrict total chiller
operation, eg. during emergency generator operations.
External circuit lockout will only function if External Circuit Lockout (Service
Setting Menu) is enabled.
These customer-supplied contact closures must be compatible with 12 VDC,
45 mA resistive load. Silver or gold plated contacts are recommended.
To install, cut, strip and wire-nut existing wire loop #4 on the P53 connector
of the 1U5 module to low voltage leads 46A and 46B. Connections are shown
in the field diagrams which are shipped with the unit.

Ice Making Option

Ice Machine Control (Operator Settings Menu) must be Enabled. The UCM
provides auxiliary control for a customer specified/installed contact closure
for ice making. When contact (5K20) is provided, the chiller will run normally
when the contact is open. Upon contact closure, the UCM 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 setting under Active Ice Termination Set-point
(Chiller Report Menu). The UCM will not permit the ice-building mode to be
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