Trane Rtaaiom3 Manual

71RTAA-IOM-3
Alarm/Running/Maximum
Capacity Indicator Wiring
If the optional remote Alarm/Running/
Maximum Capacity contacts are used,
provide electrical power, 115 VAC
(contact load not to exceed 1150 VA
inrush, 115 VA sealed), with fused-
disconnect to a customer-furnished
remote device. Also provide proper
remote device ground connection.
To install the available remote running
and alarm indication, the installer must
provide leads 525 thru 532 from the
panel to the proper terminals of
terminal strip...

72RTAA-IOM-3
External Chilled Water
Setpoint (CWS):
Remote Resistor/Potentiometer,
Voltage Source 2-10 VDC, or
Current Source 4-20 mA
This option allows the external setting
of the Chilled Water Setpoint,
independent of the Front Panel Chilled
Water Setpoint, by one of three means:
1. A remote resistor/potentiometer
input (fixed or adjustable)2. An isolated voltage input 2-10 VDC
3. An isolated current loop input
4-20 mA
Methods 2 and 3 are usually used in
interfacing with a Generic BAS or a
process...

73RTAA-IOM-3
2. Isolated 2-10 VDC Voltage Source
Input
Set DIP Switch SW1-1 of Options
Module 1U2 to “OFF”. Connect the
voltage source to terminals TB1 -4 (+)
and TB1 -5 (-) on Options Module
1U2. CWS is now based on the
following equation:
CW Setpoint 0 F = (VDC x 8.125) -
16.25
Sample values for CWS vs. VDC
signals are shown in Table 13.
Minimum setpoint
= 0 F (2.0 VDC input)
Maximum setpoint
= 65 F (9.4 VDC input)
Maximum continuous input voltage
= 15 VDC
Input impedance = 40.1 Kohms
SW1 -1 off)
3....

74RTAA-IOM-3
If the potentiometer is to be remotely
mounted, it and the resistor must be
connected to the UCM prior to
mounting. Then, with the UCM display
in Menu 0 and the display advanced to
“Active Current Limit Setpoint”, the
UCM can be used to calibrate the
positions of the potentiometer to
correspond with the desired settings
for the current limits. External resistor
input values for various current limit
setpoints are shown in Table 14.
2. 2-10 VDC Voltage Source Input
Set DIP Switch SW1-2 of...

75RTAA-IOM-3
Installation Check List
Complete this checklist as the unit is
installed, to verify that all
recommended procedures are
accomplished before the unit is started.
This checklist does not replace the
detailed Instructions given in the
“Installation -Mechanical” and
“Installation -Electrical” sections of this
manual. Read both sections
completely, to become familiar with the
installation procedures, prior to
beginning the work.
Receiving
[  ] Verify that the unit nameplate data
corresponds to...

76RTAA-IOM-3 

77RTAA-IOM-3
Operating
Principles –
Mechanical
General
This section describes the mechanical
operating principles of Series R air-
cooled chillers equipped with
microcomputer-based control systems.
The 130 thru 400-ton Model RTAA units
are dual-circuited, helical-rotary type
air-cooled liquid chillers. The basic
components of an RTAA unit are:
- Unit Control Module (UCM)
- Unit-mounted panel
- Helical-rotary compressor
- Direct Expansion evaporator
- Air-cooled condenser
- Oil supply system (hydraulic...

78RTAA-IOM-3
Figure 40
Refrigeration System and
Control Components
Single Circuit(Continued on Next Page) 

79RTAA-IOM-3
Figure 40
(Continued from Previous Page)
1 Schrader valve
2 Suction temperature sensor*
3 Manufacturing process tube
4 Suction service valve (optional)
5 Motor winding thermostat*
6 Discharge temperature sensor*
7 Pressure relief valve (450 psi)
8 High pressure cutout (405 psi)*
9 Discharge check valve
10 Evaporator waterside vent
11 Discharge line shutoff valve
12 Oil separator in/out cap
13 Saturated condensing temperature
sensor*
14 Condenser header
15 Subcooler header
16 Liquid line...

80RTAA-IOM-3
Figure 41
Refrigeration System and
Control Components
Duplex Circuit(Continued on Next Page)