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Refrigerant Piping
IMPORTANT: Do not bury refrigerant piping underground.
See Tables 1-4 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 FAS/FHS direct-expansion units have internal factory-
installed thermostatic expansion valves (TXVs), distributors,
and nozzles for use with R-410A. See Table 8 for part num-
bers. Knockouts are provided in the unit corner posts for
FAS/FHS refrigerant piping. See Fig. 7, which also lists rec-
ommended knockouts and access holes to use for each
FAS/FHS unit size. Recommended fittings are listed in
Table 9.
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. 8.)
Refrigerant Piping Access
The FAS/FHS units come with standard knockouts for refrig-
erant 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 FAS072,
091, 120, 150, and 180 and FHS072, 091, and 120 units.
FAS-FHS-072-180-01SI Rev. A
OVERHEAD SUSPENSION ACCESSORY
UNIT SIZES 07 - 12
UNIT SIZES 14 - 16
Fig. 6 — Preferred Suspension Technique
Specifications subject to change without notice.
NOTE: Dimensions in [ ] are millimeters.
FHS180 units require additional holes that must be field-
fabricated to accommodate the piping. See Fig. 7 for the
positions and dimensions of the additional access holes re-
quired for RHS180 units. Recommended access hole use is
also listed for all units. Note that Fig. 7 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.
NOTE: Be sure to remove the styrofoam shipping pad from
the TXV. Verify that it has been removed. (See Fig. 4.)
IMPORTANT: Never attach the sensor to the suction man-
ifold. Do NOT mount the sensor on a trapped portion of
the suction line.
The FAS/FHS 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. 9.)
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. 10.)
13
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