Carrier 40RU 25, Manual

Page: 15 / 40

15
Unit Isolation
Where extremely quiet operation is essential, install isolators be -
tween floor and base of unit, or between ceiling and top section of
unit.
Be sure that unit is level and adequately supported. Use channels
at front and sides of unit for reference points when leveling.
Refrigerant and Chilled Water Piping Access
The 40RU Series units come with standard knockouts for refriger -
ant and chilled water piping. These knockouts are located on both
sides of the unit for installation flexibility. The standard knockouts
provide sufficient access to the unit’s coils for all 40RUA*25, 28,
and 30 units. 40RUQ*25 units, as well as 40RUS*25, 28, and
30 units require additional holes which must be field-fabricated to
accommodate the piping. See Fig. 8 for the positions and dimen -
sions of the additional access holes required for 40RUQ and
40RUS units. Recommended access hole use is also listed for all
units. Note that Fig. 8 shows the access holes on the control-box
side of the unit; this is the side of the unit with the coil headers,
which is used most often for piping access.
Refrigerant Piping
See Tables 1-6 for refrigerant pipe connection sizes. For ease in
brazing, it is recommended that all internal solder joints be made
before unit is placed in final position.
The 40RU direct-expansion units have internal factory-installed
thermostatic expansion valves (TXVs), distributors, and nozzles
for use with R-410A. See Table 7 for part numbers. Knockouts are
provided in the unit corner posts for 40RU refrigerant piping. See
Fig. 8, which also lists recommended knockouts and access holes
to use for each 40RU unit size. Recommended fittings are listed in
Table 8.
The sensor bulb capillary tubes must be routed from the TXVs in -
side the unit through one of the piping access holes. Clamp the
TXV sensor bulb on a vertical portion of the suction line, outside
the unit. (See Fig. 9.)
NOTE: Be sure to remove the styrofoam shipping pad from the
TXV. Verify that it has been removed. (See Fig. 5.)
The 40RU Series evaporator coils have a face-split design. Ensure
that lower circuit of coil is first on/last off when connected to the
condensing unit and/or system controls. (See Fig. 10.)
External TXV equalizer connections are provided and factory-
brazed into the coil suction manifolds.
If suction line must be horizontal, clamp bulb to suction line at
least 45 degrees above bottom, at approximately the 4 o’clock or
8 o’clock position. (See Fig. 11.)
Fig. 8 — Refrigerant and Chilled Water Piping Access Holes
IMPORTANT: Do not bury refrigerant piping underground.
IMPORTANT: Never attach the sensor to the suction manifold.
Do NOT mount the sensor on a trapped portion of the suction
line.
4
3
2
1
7
6
5
A
B
C
D
8
UNIT
USE HOLE
NO.
a
FIELD-FABRICATED HOLE DIAMETERS
in (mm)
FIELD-FABRICATED HOLE POSITION
DIMENSIONS in. (mm)
NO. 5 NO. 6 NO.7 NO.8 A B C D
40RUA*25,28,30 1,2,3,4 — — — — — — — —
40RUS*25 4,5,6,7 1-3/4 (44.5) 1-3/4 (44.5) 1-3/4 (44.5) — 3.0 (76.2) 6.0 (152.5) 10.5 (266.7) —
40RUQ*25 3
b
,5,6,7 1-1/8 (28.6) 1-1/8 (28.6) 1-3/4 (44.5) — 3.25 (82.6) 6.125 (155.6) 10.38 (263.7)
40RUS*28,30 5,6,7,8 2-1/2 (63.5) 2-1/2 (63.5) 2-1/2 (63.5) 2-1/2 (63.5) 6.0 (152.5) 9.625 (244.50) 13.38 (339.9) 17.0 (431.8)
NOTE(S):
a. Access hole knockouts 1-4 are factory-supplied.
b. Must be enlarged from 1-1/8 in. (28.6mm) to 1-3/4 in. (44.5mm)