13
Fig. 6 — Preferred Suspension Technique
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 524J direct-expansion units have internal factory-installed
thermostatic expansion valves (TXVs), distributors, and
nozzles for use with R-410A. See Table 8 for part numbers.
Knockouts are provided in the unit corner posts for 524J refrig
-
erant piping. See Fig. 7, which also lists recommended knock
-
outs and access holes to use for each 524J unit size. Recom
-
mended 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 524J Series 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 524J*07A, 08A, 12A,
14A, and 16A and 524J*07H, 08H, and 12H units. 524J*16H
units require additional holes that must be field-fabricated to
accommodate the piping. See Fig. 7 for the positions and di
-
mensions of the additional access holes required for 524J*16H
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.)
The 524J Series evaporator coils have a face-split design.
Ensure that lower circuit of coil is first on/last off when con
-
nected 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.)
NOTE: Dimensions in [ ] are millimeters.
UNIT SIZES 07 - 12
OVERHEAD SUSPENSION ACCESSORY
UNIT SIZES 14 - 16
IMPORTANT: Never attach the sensor to the suction mani
-
fold. Do NOT mount the sensor on a trapped portion of the
suction line.
