Trane Rtaaiom3 Manual

							51RTAA-IOM-3
Table 4
Liquid Line Size for Horizontal and/or Downflow Lines
Circuit Size: Liquid Line Size (OD”)Total Equiv. Length (Ft) 100 Ton 85 Ton 70 Ton25 1 1/8 1 1/8 1 1/8
50 1 3/8 1 1/8 1 1/8
75 1 3/8 1 3/8 1 3/8
100 1 3/8 1 3/8 1 3/8
125 1 3/8 1 3/8 1 3/8
150 1 5/8 1 3/8 1 3/8
175 1 5/8 1 5/8 1 5/8
200 1 5/8 1 5/8 1 5/8
225 1 5/8 1 5/8 1 5/8
250 1 5/8 1 5/8 1 5/8
275 1 5/8 1 5/8 1 5/8
300: 1 5/8 1 5/8 1 5/8
Table 5
Equivalent Lengths of Non-Ferrous valves and Fittings
Line Size Globe Angle Short Long
Inches OD Valve Valve Radius ELL Radius ELL
1 1/8 87 29 2.7 1.9
1 3/8 102 33 3.2 2.2
1 5 /8 115 34 3.8 2.6
2 1/8 141 39 5.2 3.4
2 5/8 159 44 6.5 4.2
3 1/8 185 53 8.0 5.1
3 5/8 216 66 10.0 6.3
4 1/8 248 76 12.0 7.3
Reproduced by permission of Air conditioning and Refrigeration Institute.
Line Sizing
Equivalent Line Length
To determine the appropriate size for
field installed liquid and suction lines, it
is first necessary to establish the
equivalent length of pipe for each line.
An initial approximation can be made
by assuming that the equivalent length
of pipe is 1.5 times the actual length of
pipe. These assumed lengths can then
be used with the appropriate tables in
the Liquid Line Sizing section and the
Suction Line Sizing sections which
follow.
It is also necessary to know the
capacity (tons) of each circuit. Circuit
capacities for each RTAA unit are listed
in Table 3.The following are examples of how to
determine line sizes.
Liquid Line Sizing
This example uses the unit installation
shown in Figure 31 and assumes an 85
ton circuit. The actual length of field
installed piping is 117 feet (80 + 8 + 8 +
21). Using the factor of 1.5, the
equivalent line length is 175 feet.From Table 4, for horizontal and/or
downflow liquid lines, and assuming
an 85 ton circuit, 175 feet of equivalent
line requires a liquid line with an OD of
1 5/8 in.
There are 6 long-radius elbows in this
example. Using Table 5 and the pipe
OD of 1 5/8 in., these fittings represent
15.6 feet (6 elbows @ 2.6 feet each).
Therefore our new equivalent line
length is 132.6 feet (117 +15.6).
Referring back to Table 4, an 85 ton
circuit with 132.6 feet of equivalent pipe
length (use the dimension closest to
the calculated dimension) can use a
pipe O.D. of 1% in. rather than 1 5/8 in.
From Table 5 we see that the 6 elbows
of 1 3/8 in. have an equivalent pipe
length of 13.2 feet (6 elbows @ 2.2 feet
each). This further reduces the
equivalent pipe length to 130.2 feet
(117 + 13.2), and, as shown in Table 4,
still allows the use of 1 3/8 in. O.D. pipe.
Table 3
RTAA Circuit Capacities
Model Circuit 1 Circuit 2130 70 70
140 70 70
155 85 70
170 100 70
185 100 85
200 100 100 
						

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RTAA-IOM-3
Figure 31 
Remote Evaporator Piping Example 
						

							53RTAA-IOM-3
Suction Line Sizing
This example uses the unit installation
shown in Figure 31 and assumes a 100
ton circuit. As in the liquid line sizing
example, the equivalent pipe length
must first be determined. It must also
be determined what portion of the pipe
is “horizontal and/or downflowing”
and what portion is “horizontal and/or
upflowing.”
In Figure 31, the actual length of field
installed piping is 100 feet (20 + 5 + 75).
Using the factor of 1.5, the equivalent
line length is 150 feet. The suction line
has an elevation of 20 feet and consists
of horizontal and vertical (upflowing)
sections, which must be sized
separately.
The two vertical sections are separated
by a small horizontal section. The total
distance is 25 feet (20 +5). The first
approximation of equivalent pipe
length is 37.5 feet (1.5 times 25).
Referring to Table 6 for a horizontal
and/or upflow suction line on a 100 ton
circuit with 37.5 feet of line, the pipe
O.D. should be 3 1/8 in.Add the 75 feet of horizontal and/or
downflow line to the 45.4 feet of
horizontal and/or upflow line, resulting
in 120.5 of equivalent pipe length. Table
7 at 125 feet (use the dimension closest
to the calculated dimension) indicates
the use of 4 1/8 in. O.D. pipe. Therefore,
the 4 1/8 in line will have to be reduced
for the vertical sections of the line and
expanded again for the horizontal
sections. There are four long-radius elbows in
this section of piping. Using Table 5
and the pipe OD of 3 1/8 in., these
fittings represent 20.4 feet (4 elbows @
5.1 feet each). Therefore our new
equivalent line length is 45.4 feet (25 +
20.4). Table 6 indicates that 45.4
equivalent feet still permits the use of 3
1/8 in. O.D. pipe.
In sizing the horizontal and/or
downflow portion of the suction line, it
is necessary to account for the total
equivalent length of the line.
Note: In this example, the horizontal
line is pitched downward in the
direction of flow
Using Table 7 and 150 feet of
equivalent pipe length for a 100 ton
circuit, a pipe O.D. of 4 1/8 in. is
specified. There are no fittings in the 75
foot horizontal run, so no equivalent
fitting lengths need to be determined.
Table 6
Suction Line Size for Horizontal and/or Upflow Lines
Circuit Size: Suction Line Size (OD”)Total Vertical Equiv. Length (Ft) 100 Ton 85 Ton 70 Ton50: 3 1/8 3 1/8 2 1/8
75: 3 1/8 3 1/8 2 1/8
100: 3 1/8 3 1/8 2 1/8
Table 7
Suction Line Size for Horizontal and/or Downflow Lines
Circuit Size:
Total Equiv. Length (Ft) Suction Line Size (OD”)
(Including vertical section, if any) 100 Ton 85 Ton 70 Ton50: 3 1/8 3 1/8 2 5/8
75: 3 1/8 3 1/8 2 5/8
100: 3 1/8 3 1/8 3 1/8
125: 4 1/8 3 1/8 3 1/8
150: 4 1/8 3 1/8 3 1/8
175: 4 1/8 4 1/8 3 1/8
200: 4 1/8 4 1/8 3 1/8
225: 4 1/8 4 1/8 3 1/8
250: 4 1/8 4 1/8 3 1/8
275: 4 1/8 4 1/8 3 1/8
300: 4 1/8 4 1/8 3 1/8 
						

							54RTAA-IOM-3
Piping Installation
Procedures
The outdoor unit and the evaporator
are shipped with a 25 psig holding
pressure of dry nitrogen. Do not relieve
this pressure until field installation of
the refrigerant piping is to be
accomplished. This will require the
removal of the temporary pipe caps.
Note: Use Type L refrigerant-grade
copper tubing only.
The refrigerant lines must be isolated
to prevent line vibration from being
transferred to the building. Do not
secure the lines rigidly to the building
at any point.
All horizontal suction lines should be
pitched downward, in the direction of
flow, at a slope of 1/2 in. per 10 feet of
run, This allows for larger line size,
which will improve unit efficiency.
Do not use a saw to remove end caps,
as this may allow copper chips to
contaminate the system. Use a tubing
cutter or heat to remove the end caps.
When sweating copper joints, flow dry
nitrogen through the system. This
prevents scale formation and the
possible formation of an explosive
mixture of R-22 and air. This will also
prevent the formation of toxic
phosgene gas, which occurs when
refrigerant is exposed to open flame.
WARNING: To prevent Injury or
death, due to explosion and/or
inhalation of phosgene gas,
purge the system thoroughly
while sweating connections. Use
a pressure regulator in the line
between the unit and the high
pressure nitrogen cylinder to
avoid over-pressurization and
possible explosion.
Refrigerant Sensors
The suction line refrigerant sensors
must be installed by the contractor
installing the refrigerant piping. The
sensors are pre-wired and each is
“wire-tied” to its respective liquid line.
Fittings and adapters for mounting of
the sensors are located in the remote
evaporator terminal box. See Figure 32
for mounting instructions. 
						

							55RTAA-IOM-3
Figure 32
Customer Interconnect Wiring for
RTAA Outdoor unit with Remote Evaporator –
130 to 200 Tons
2306-9133A 
						

							56RTAA-IOM-3
Leak Test and Evacuation
After installation of the refrigerant
piping, thoroughly test the system for
leaks. Pressure test the system at
pressures required by local codes.
Immediately before evacuation, install
the liquid line filter cores. These will be
shipped with the evaporator.
Note: Do not install these before the
circuit is ready for evacuation, as the
cores will absorb moisture from the
atmosphere.
For field evacuation, use a rotary-type
vacuum pump capable of pulling a
vacuum of 100 microns or less. Follow
the pump manufacturer’s instructions
for proper use of the pump. The line
used to connect the pump to the
system should be copper and be the
largest diameter that can be practically
used. A larger line size with minimum
flow resistance can significantly reduce
evacuation time.
Use the ports on the compressor
suction service valves and the liquid
line shutoff valves for access to the
system for evacuation. Insure that the
compressor suction service valve, the
liquid line shutoff valve, the oil line
shutoff valve and any field installed
valves are open in the proper position
before evacuating.
Insulate the entire suction line and the
suction accumulator line. Where the
line is exposed to the weather, wrap it
with weatherproof tape and seal with
weatherproof compound.
Refrigerant and
Additional Oil Charge
Refrigerant Charge
Determination
The approximate amount of refrigerant
charge required by the system must be
determined by referring to Table 8 and
must be verified by running the system
and checking the liquid line
sightglasses.
Table 8
System Refrigerant Charge
Circuit Size Lbs. of R-2270 130
85 165
100 170
To determine the appropriate charge,
first refer to Table 8 to establish the
required charge required without the
field-installed piping. Next, determine
the charge required for the field-
installed piping by referring to Table 9.
Table 9
Field-installed Piping Charge
Pipe O.D. Suction Liquid
(inches) Line Line
1 3/8 1.2 63.0
1 5/8 1.7 89.2
2 1/8 2.9 155.2
2 5/8 4.5 239.4
3 1/8 6.4 —
4 1/8 11.3 —
Note: The amounts of refrigerant listed
in Table 9 are based on 100 feet of pipe.
Actual requirements will be in direct
proportion to the actual length of
piping.
Note: Table 9 assumes:
Liquid Temperature = 100 F
Suction Temperature = 35 F
Suction Superheat Temperature = 8 FThe approximate amount of refrigerant
is therefore the sum of the values
determined from Tables 8 and 9.
Example:
Determine the approximate amount of
charge required for an RTAA 200 ton
unit with a remote evaporator that is
located 75 feet away (i.e. the actual
length of field installed pipe is 75 feet
for each suction line and liquid line).
Assume that the suction lines have
been previously determined to be 4 1/8
in., O.D. and the liquid lines are 1 3/8 in.
O.D.
A 200 ton unit has two 100 ton circuits.
From Table 8 above, a 100 ton circuit
requires 170 lbs. of R-22. In addition,
the 4 1/8 in. 0. D. suction line for the 100
ton circuit will require 11.3 lbs. per 100
feet of the 75 feet of line will therefore
require 8.5 lbs. (11.3 times 75/100).
Similarly from Table 9, the 1 3/8 in. O.D.
liquid line will require 47.3 lbs. of R-22
(63 times 75/100). The total R-22 charge
for the 100 ton circuit will be 225.8 lbs.
(170 + 8.5 + 47.3). And because the
RTAA 200 has two 100 ton circuits, the
total system charge will be twice as
much, or 461.6 lbs.
Oil Charge Determination
The unit is factory charged with the
amount of oil required by the system,
without the field-installed piping. The
amount of additional oil required is
dependent upon the amount of
refrigerant that is added to the system
for the field-installed piping.
Use the following formula to calculate
the amount of oil to be added:
Pints of Oil (Trane Oil-15) = lbs. of
refrigerant added for field-installed
piping/18.375
From the example above, in which the
weight of the additional refrigerant
added for the field-installed piping was
55.8 lbs. (47.3 + 8.5), the amount of oil
to be added equals 3 pints (55.8/18.375)
per circuit. 
						

							57RTAA-IOM-3
Installation –
Electrical
Figure 33
Warning Label
General
Recommendations
WARNING: The Warning Label
shown in Figure 33 is displayed
on the equipment and shown on
wiring diagrams and schematics.
Strict adherence to these
warnings must be observed.
All wiring must comply with local
codes and the National Electric Code.
Typical field wiring diagrams are
shown in Figures 34 thru 36. Minimum
circuit ampacities and other unit
electrical data are on the unit
nameplate and are shown in Table 10.
See the unit order specifications for
actual electrical data. Specific electrical
schematics and connection diagrams
are shipped with the unit.
Caution: To avoid corrosion and
overheating at terminal
connections, use copper
conductors only.
Do not allow conduit to interfere with
other components, structural members
or equipment.
Control voltage (115V) wiring in
conduit must be separate from conduit
carrying low voltage (
						

							58RTAA-IOM-3
(Continued on Next Page)Figure 34
Typical Field Wiring for
RTAA Packaged Unit –
130 to 200 Tons 
						

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(Continued from Previous Page)
See Notes on Next Page 
						

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Figure 34 (Continued from Last Page)
Typical Field Wiring for
RTAA Packaged Unit –
130 to 200 Tons
2306-9123-A