Specifications

13
Unit Positioning —
The unit can be mounted on the
floor for vertical application with return air entering the face of
the unit and supply air discharging vertically through the top of
the unit. The unit can also be applied in a horizontal arrange-
ment with return air entering horizontally and the supply air
discharging horizontally. When applying the unit in a horizon-
tal arrangement, ensure the condensate drain pan is located at
the bottom center of the unit for adequate condensate disposal.
See Fig. 4 for condensate connections for each unit position.
Typical positioning and alternate return air locations are
shown in Fig. 4. Alternate return air locations can be used by
moving the unit panel from the alternate return air location to
the standard return air location. Refer to overhead suspension
accessory drawing (Fig. 5) for preferred suspension technique.
The unit needs support underneath to prevent sagging.
Unit Isolation —
Where extremely quiet operation is
essential, install isolators between 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 40RM Series units come with standard
knockouts for refrigerant 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 40RM and some 40RMQ units, however,
for 40RMQ016,028 and 40RMS units, additional holes must
be field-fabricated to accommodate the piping. See Fig. 6 for
the positions and dimensions of the additional access holes re-
quired for these units, including hole diameters and drilling
dimensions. Recommended access hole use is also listed for all
units. Note that Fig. 6 shows the access holes on the control-
box side of the unit; this is the side of the unit with the coil
headers, so it is used most often for piping access.
Refrigerant Piping —
See Tables 1A, 1B, 1D, 1E for
refrigerant pipe connection sizes. For ease in brazing, it is rec-
ommended that all internal solder joints be made before unit is
placed in final position.
The 40RM and 40RMQ direct-expansion units have inter-
nal factory-installed thermostatic expansion valves (TXVs),
distributors, and nozzles for use with R-22. See Table 2 for part
numbers. Knockouts are provided in the unit corner posts for
40RM and 40RMQ008 and 012 refrigerant piping. The
40RMQ016,024 and 028 units requires additional field-
fabricated piping access holes. See Fig. 6, which also lists rec-
ommended knockouts and access holes to use for each 40RM
and 40RMQ unit size. Recommended fittings are listed in
Table 3.
The sensor bulb capillary tubes must be routed from the
TXVs inside 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. 7.
NOTE: Be sure to remove the styrofoam shipping pad from
the TXV. Verify that it has been removed. See Fig. 3.
The 40RM 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. 8.
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. 9.
NOTE: The 40RMQ units are supplied with factory-installed
thermostatic expansion valves and check valve bypasses. No
extra piping connections or kits are required to install the
40RMQ with a 38AQS condensing unit in a heat pump
system, however, some field supplied components may be
required. See the following two sections.
38AQS008/40RMQ008 HEAT PUMP SYSTEM PIP-
ING — Addition of a liquid solenoid valve (LLSV) is recom-
mended when the piping system length exceeds 75 feet. The
LLSV must be a bi-flow type suited for use in heat pump
systems. The recommended valve is Sporlan model CB14S2
(
5
/
8
-in. ODF,
7
/
8
-in. ODM) available from the Replacement
Components Division as part number EF23JS-214. This sole-
noid valve requires Sporlan part no. MKC-2 coils that must be
purchased locally. Wire the solenoid valve in parallel with the
compressor contactor coil.
The LLSV must be installed at the outdoor unit with the
flow arrow pointed toward the outdoor unit (in-flow direction
for the heating mode.)
38AQS DUPLEX/40RMQ024 HEAT PUMP SYSTEM
PIPING — Two 38AQS012 heat pump condensing units may
be connected in a duplex arrangement with the 40RMQ024.
See Fig. 10. Ensure that the lower circuit of the 40RMQ coil is
the first on/last off by connecting to the “A” condensing unit
and by configuring the controls so that the “A” condensing unit
is the first on/last off.
38AQS012/016 DUPLEX/40RMQ028 HEAT PUMP SYS-
TEM PIPING — One 38AQS012 and one 38AQS016 heat
pump condensing unit may be connected in a duplex arrange-
ment with the 40RMQ028. See Fig. 10. The 40RMQ028 has a
60/40 face split coil. Ensure that the larger coil section is con-
nected to the 38QAS016 and the smaller coil section is con-
nected to the 38AQS012. In addition, ensure that the lower cir-
cuit of the 40RMQ coil is the first on/last off by connecting to
the “A” condensing unit and by configuring (see 38AQS size
012-016 installation instructions for more information) the
controls so that the “A” condensing unit is the first on/last off.
FILTER DRIER REQUIREMENTS FOR 38AQS012/
40RMQ012, 38AQS016/40RMQ016, 38AQS012/
40RMQ024 AND 38AQS012,016/40RMQ028 HEAT PUMP
SYSTEMS — The 38AQS012 and 016 units do not include
filter driers. Filter driers must be field-supplied and installed in
38AQS012/40RMQ012, 38AQS016/40RMQ016, 38AQS012/
40RMQ024 and 38AQS012,016/40RMQ028 systems. The
filter driers used with these systems must be bi-flow types suit-
ed for use in heat pump applications. The Replacement Com-
ponent Division part numbers listed in Fig. 11 are recommend-
ed and available for field installation.
IMPORTANT: Do NOT attempt to install unit with return
air entering top panel of unit. Condensate will not drain
from unit.
IMPORTANT: Never attach the sensor to the suction
manifold. Do NOT mount the sensor on a trapped portion
of the suction line.
LEGEND
Fig. 4 — Typical Unit Positioning
Accessory Line
Alternate Air Intake and Discharge
Air Intake and Discharge