Trane Rtaaiom3 Manual

							81RTAA-IOM-3
Figure 41
(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 shutoff valve17 25 micron filter/drier
18 Liquid line sight glass
19 Electronic expansion valve*
20 Saturated evaporator temperature
sensor*
21 Evaporator waterside drain
22 Leaving water temperature sensor*
23 Leaving water connection
24 Entering water connection
25 Entering water temperature sensor*
26 Drain with Schrader valve
27 Oil line
28 Entering oil, cooler header
29 Leaving oil cooler header
30 Schrader valve with stem depressor
31 Oil line shutoff valve
32 5 micron oil filter33 Master solenoid valve*
34 Oil line to load/unload slide valve
solenoids
35 Injection oil check valve
36 Heater
37 Slide valve solenoids and orifices*
38 Oil flow differential pressure switch*
39 Compressor Drain Plug
40 Domestic water heater (optional)
41 Oil line thermostat (option,
Domestic Water Heater)
42 Oil line bypass solenoid valve
(option, Domestic Water Heater)
*UCM Input/Output Control
Figure 42
Typical RTAA Compressor
REFRIGERATION SYSTEM AND CONTROL COMPONENTS 
						

							82RTAA-IOM-3
Figure 43
RTAA Compressor Oil System
Schematic
Oil System Operation
Overview
Oil that collects in the bottom of the oil
separator is at condensing pressure
during compressor operation;
therefore, oil is constantly moving to
lower pressure areas. Refer to
Figure 43.
As the oil leaves the separator, it passes
through the air-cooled oil cooler at the
top of the condensing coils. It then
goes through the service valve and
filter. At this point, some of the oil is
used to control the slide valve
movement in the compressor, via the
load/unload solenoids. The remaining
oil passes through the oil master
solenoid valve and performs the
functions of compressor bearing
lubrication and compressor oil
injection. If the compressor stops for
any reason, the master solenoid valve
closes, isolating the oil charge in the
separator and oil cooler during “off”
periods.To ensure proper lubrication and
minimize refrigerant condensation in
the compressor, a heater is mounted
on the bottom of the compressor
housing. A signal from the UCM
energizes this heater during the
compressor “Off” cycle to keep
refrigerant from condensing in the
compressor. The heater element is
continuously energized.
Domestic Water Heater
The Domestic Water Heater option
utilizes available waste heat from the
compressor oil circuit, to heat domestic
or process water. Normally, the excess
heat is dissipated to the atmosphere by
fans moving air over the oil cooler.
The high temperature oil that leaves
the oil separator enters the domestic
water heater. Heat is transferred from
the oil to the cool water that enters the
heater. The oil then passes either
through the unit’s air-cooled oil cooler,
where additional heat is removed, if
required, or through the air-cooled oil
cooler bypass solenoid, that is
operated by a thermostat on the oil
supply line.
Water that is heated in the domestic
water heater exits the heater and flows
to the system. 
						

							83RTAA-IOM-3
Oil Separator
The oil separator consists of a U-
shaped tube, joined at the top by the
refrigerant discharge line from the
compressor. As shown in Figure 44, the
discharge line is essentially tangential
to the U-tubes. This causes the
refrigerant to swirl in the tubes and
throws the oil to the outside, where it
collects on the walls and flows to the
bottom. The compressed refrigerant
vapor, stripped of oil droplets, exits out
the top of the oil separator and is
discharged into the condensing coils.
Compressor Bearing Oil Supply
Oil is injected into the bearing housings
located at each end of both the male
and female rotors. Each bearing
housing is vented to compressor
suction, so that oil leaving the bearings
returns through the compressor rotors
to the oil separator.
Compressor Rotor Oil Supply
Oil flows through this circuit directly
from the master solenoid valve
through the oil filter to the top of the
compressor rotor housing. There it is
injected along the top of the rotors to
seal clearance spaces between the
rotors and the compressor housing
and to lubricate the rotors.
Figure 44
Oil Separator 
						

							84RTAA-IOM-3
Slide Valve Movement
Movement of the slide valve piston
determines slide valve position which,
in turn, regulates compressor capacity.
Oil flow into and out of the cylinder
governs piston movement, and is
controlled by the normally-closed, load
and unload solenoid valves.
The solenoid valves receive
momentary pulsating “load” and
“Unload” voltage signals from the
UCM based on system cooling
requirements. 
To load the compressor,
the UCM opens the load solenoid valve
while keeping the unload solenoid
valve closed. The pressurized oil flow
then enters the cylinder and forces the
slide valve to move over the rotors.
The compressor is unloaded when the
load solenoid valve is kept closed and
the unload solenoid valve is opened.
Oil “trapped” within the cylinder is
drawn out into the lower-pressure
suction area of the compressor. As the
pressurized oil leaves the cylinder, the
slide valve gradually moves away from
the rotors.
When 
both solenoid valves are closed,
the present level of compressor loading
is maintained.
Just prior to a normal compressor
shutdown, the unload solenoid valve is
energized and the slide valve moves to
the fully-unloaded position, so the unit
always starts fully unloaded.
Oil Filter
Each refrigerant circuit is equipped with
replaceable-element oil filters. The
filter(s) remove any impurities that
could foul the solenoid valve orifices
and compressor internal oil supply
galleries. This also prevents excessive
wear of compressor rotor and bearing
surfaces. Refer to the maintenance
portion of this manual for
recommended filter element
replacement intervals.
Condenser Fans
The RTAA Series offers either the 15 F
or 0 F ambient fan configuration. On
the 0 F ambient option, the lead fan(s)
on each circuit is a half-airflow (half-
pitch blade) fan(s). Half pitch fans have
a blade pitch of 150 and full pitch fans
have a blade pitch of 27°.
Figures 45 and 46 show the number of
fans installed on each model, the
designation of fan contactors and the
staging of fans as the UCM calls for
more condenser cooling. Fan staging is
a function of the difference between
the saturated condenser refrigerant
temperature and the saturated
evaporator refrigerant temperature,
which in turn is a function of the load
and ambient temperature. Any number
of fans can be operating at a given
time, depending on these variables. 
						

							85RTAA-IOM-3
Figure 45
Fan Configurations – RTAA 130-200 Tons
15 F Minimum Ambient
All fans will be Full Airflow (Full Pitch Blade) Fans:
Circuit #1 is on the right side of the unit from the control panel.
Circuit #2 is on the left side of the unit from the control panel.
# Of Fans # Of Fans UCM  Outputs
Tons Circuit #1 Circuit #2 Per Circuit # Fan Steps/Circuit
130 5 5 4 5 & 5 respectively
140 5 5 4 5 & 5 respectively
155 6 5 4 6 & 5 respectively
170 7 5 4 7 & 5 respectively
185 7 6 4 7 & 6 respectively
200 7 7 4 7 & 7 respectively
For STANDARD air-cooled (RTAA) Chillers, the mapping of UCM outputs to fan staging shall be as follows:
Fan Contactor 5 Fan Circuit 6 Fan Circuit 7 Fan Circuit
Circuit #1 K9 K10 K11 K12 K9 K10 K11 K12 K9 K10 K11 K12
Circuit #2 K13 K14 K15 K16 K13 K14 K15 K16 K13 K14 K15 K16
Number of Fan(s)/
Contactor1112 11 22 1123
Fan Steps
0 –––– –– –– ––––
1 x––– x– –– x–––
2 xx–– x x –– xx––
3 xxx– x– x– x–x–
4 xx– x xx x– xx–x
5 xxx x x– xx x x–  x
6 –––– xx xx x–xx
7 –––– –– ––xxxx
X = ON 
						

							86RTAA-IOM-3
Figure 46
Fan Configurations - RTAA 130-400 Tons - 0 F Minimum Ambient
The 0 F AMBIENT OPTION will have Half Airflow (Half Pitch Blade) Fan.
# Of Fans # Of Fans UCM  Outputs
Tons Circuit #1 Circuit #2 Per Circuit Fan Steps/Circuit
130 5* 6* 4 9 & 10 respectively
140 5* 6* 4 9 & 10 respectively
155 6* 6* 4 10 & 10 respectively
170 7* 6* 4 11 & 10 respectively
185 7* 7* 4 11 & 11 respectively
200 7* 7* 4 11 & 11 respectively
215 7* 7* 4 11 & 11 respectively
240 10** 7* 4 9 & 11 respectively
270 12** 7* 4 10 & 11 respectively
300 14** 7* 4 11 & 11 respectively
340 10** 14** 4 9 & 11 respectively
370 12** 14** 4 10 & 11 respectively
400 14** 14** 4 11 & 11 respectively
*The first fan on each single compressor circuit is a Half Airflow (Half Pitch Blade) Fan.
**The first two fans on each dual compressor circuit are Half Airflow (Half Pitch Blade) Fans.
For 0 F AMBIENT OPTION air-cooled (RTAA) Chillers, the mapping of UCM outputs to fan staging shall be as follows:
Fan Contactor 5  & 10 Fan Circuit 6 & 12 Fan Circuit 7 & 14 Fan Circuit
Circuit #1 K9 K10  K11 K12 K9 K10  K11 K12 K9 K10  K11 K12
Circuit #2 K13 K14 K15 K16 K13 K14 K15 K16 K13 K14 K15 K16
Number of
Fans/Contactor
Single Comp. Ckt. 1* 1 1 2 1* 1 2 2 1* 1 2 3
Dual Comp. Ckt.  2* 2 2 4 2* 2 4 4 2* 2* 2 4 6
* = Half AirFlow Fan
Fan Steps
Single Dual
ComprCompr
Ckt Ckt
0.0 0.0 –––– –– –– ––––
0.5 1 x––– x– –– x–––
1 2 –x–– –x –– –x––
1.5 3 xx–– xx –– xx––
2 4 –xx– –– x– ––x–
2.5 5 xx x– x– x– x–x–
3 6 –x–x –x x– –––x
3.5 7 x x – x x x x – x – – x
4 8 –xxx –– xx –x–x
4.5 9 xxxx x– xx xx–x
5.5 11 –––– xx xx x–xx
6.5 13 –––– –– ––xxxx
X = ON 
						

							87RTAA-IOM-3
Operating Principles –
Adaptive Control
™
Microprocessor Logic
General
The exclusive Trane Adaptive Control
logic is comprised of a system of
individual modules called the Unit
Control Module (UCM), located in the
Control Panel. The system consists of
four types of microprocessor-based
components and the operator interface,
as shown in Figures 47 thru 51. The
processors are:
Chiller Module (Base or Deluxe) - 1U1
Communication and Setpoint Reset
Option Module - 1U2
Expansion Valve Module - 1U3
Compressor Module (one per
 compressor) - 1U4, 1U5, 1U6, 1U7
Slave Expansion Valve Module
(240 -400 ton units) - 1U8
The Adaptive Control Chiller Module is
available in two versions, a base model
and a deluxe model. The deluxe model
offers the additional features of:
1. Under/Over Voltage Protection
(Includes U/O voltage sense
transformer).
2. Display of Compressor Starts and
Hours
3. Display of % Line Volts
4. Alarm/Running/Max Capacity
Contacts
Local operator interface with the
system is accomplished using the four
display buttons on the LICK Data
readouts are shown on the seven-digit,
digital display. The three-position
switch is used to set chiller operation.
Digital Display
The digital display shows:
• both operating and diagnostic codes
• compressor status indicators
• settings of a local setpoints and
adjustments
• actual controlling setpoints
• specified temperatures
• specified pressures
• enable/disable status of features and
options
• selection status of Sl units or English
units for display of temperatures and
pressures
All display segments and any used
decimal points will be briefly turned on
to provide a visual test of their
operation , following a Power-On-
Reset. The chiller operating codes (“A”
prefix) will then be displayed. The data
to be shown on the digital display is
selected by using the Display Up and
Display Down keys. Changing of the
display and menus is discussed below.
The digital display will light an indicator
at the bottom of the display, above the
“A”, “B”, “C” or “D” and circuit 1 or
circuit 2. In Menu 0, these indicators
show which compressor/circuit is
running. In Menu 2, these indicators
show which compressor/circuit is
related to the displayed parameter.
A “Circuit Lockout” indicator will be lit
if either circuit is enabled (E) in Menu 1
A (Circuit Lockout) or either circuit is
“OFF” on its external Circuit Lockout
contacts and Menu 3B, (External Circuit
Lockout) is enabled (E). 
						

							88RTAA-IOM-3
Figure 47
RTAA Control Panel –
130 to 200 Tons
LEGEND:
Device
Designation Description
1F1-6 Fan Fuses, Circuit 1
1F7-12 Fan Fuses, Circuit 2
1F15 Control Circuit Fuse
1F16, 1F17 Control Power
Transformer Fuses
1K1, 1K5 Start Contactors
1K2, 1K6 Run Contactors
1K4, 1K8 Transition  Contactors
1K3, 1K7 Shorting  Contactors
1K9-12 Fan Contactors, Circuit 1
1K13-16 Fan Contactors, Circuit 2
1S1, 1S2 Non-fused  Disconnect
Switch
1T1 Control Power
Transformer
1T2 Under/Over Voltage
Transformer
1T3-5 Compressor Current
Transformer, Circuit 1
1T6-8 Compressor Current
Transformer, Circuit 2
1TB1,1TB2 Line Voltage Terminal
Blocks
1TB3 Terminal Strip, 115 V
1U1 Chiller Module
1U2 Options Module
1U3 Expansion Valve Module
1U4 Compressor Protection
Module, Compressor A
1U5 Compressor Protection 
						

							89RTAA-IOM-3
Figure 48
RTAA Control Panel –
240 to 300 Tons
LEGEND:
Device
Designation Description
1F1-6 Fan Fuses, Circuit 1
1F7-12 Fan Fuses, Circuit 2
1F15 Control Circuit Fuse
1F16, 1F17 Primary  Transformer
Fuses
1K1, 1K2 Start Contactors, Circuit 1
1K3, 1K4 Start Contactors, Circuit 2
1K9-12 Fan Contactors, Circuit 1
1K13-16 Fan Contactors, Circuit 2
1S1, 1S2 Non-fused  Disconnect
Switch
1T1 Control Power
Transformer
1T2 Under/Over Voltage
Transformer
1T3-8 Compressor Current
Transformer, Circuit 1
1T9-14 Compressor Current
Transformer, Circuit 2
1TB1,1TB2 Line Voltage Terminal
Blocks
1TB3,1TB4 Terminal Strip, 115 V
1U1 Chiller Module
1U2 Options Module
1U3 Expansion Valve Module
1U4 Compressor Protection
Module, Compressor A
1U5 Compressor Protection
Module, Compressor B
1U6 Compressor Protection
 Module, Compressor C
1U8 Slave Expansion Valve
Module 
						

							90RTAA-IOM-3
Figure 49
RTAA Control Panel –
340 to 400 Tons
LEGEND:
Device
Designation Description
1F1-6 Fan Fuses, Circuit 1
1F7-12 Fan Fuses, Circuit 2
1F15 Control Circuit Fuse
1F16, 1F17 Primary  Transformer
Fuses
1K1, 1K2 Start Contactors, Circuit 1
1K3, 1K4 Start Contactors, Circuit 2
1K9-12 Fan Contactors, Circuit 1
1K13-16 Fan Contactors, Circuit 2
1S1, 1S2 Non-fused  Disconnect
Switch
1T1 Control Power
Transformer
1T2 Under/Over Voltage
Transformer
1T3-8 Compressor Current
Transformer, Circuit 1
1T9-14 Compressor Current
Transformer, Circuit 2
1TB1,1TB2 Line Voltage Terminal
Blocks
1TB3,1TB4 Terminal Strip, 115 V
1U1 Chiller Module
1U2 Options Module
1U3 Expansion Valve Module
1U4 Compressor Protection
Module, Compressor A
1U5 Compressor Protection
Module, Compressor B
1U6 Compressor Protection
 Module, Compressor C
1U7 Compressor Protection
 Module, Compressor D
1U8 Slave Expansion Valve
Module