Specifications

APPLICATION DATA
1. Unit selection
Select equipment so that capacity either matches or is
slightly less than anticipated peak load. This provides better
humidity control, fewer unit cycles, and less part-load
operation.
For units used in spaces with high sensible loads, base
equipment selection on unit sensible load, not on total an-
ticipated load. Adjust for anticipated room wet bulb tem-
perature to avoid undersizing equipment.
When selecting equipment that has outdoor air introduced
into the unit, determine the mix conditions of room air and
outdoor air at design conditions. The cooling capacity
tables in this literature are based on 80 F edb. Adjust for ac-
tual entering dry-bulb and wet-bulb conditions of the re-
quired outdoor air to select the proper equipment.
2. Unit combinations and coil mixed matches
The 538S units are the only units approved for use with the
619C, E and F multi-split systems. The 538S units can also
be used with other fan coil units.
Mixed matches of indoor-fan coil capacity are not recom-
mended except as listed in Systems Index Table on
page 21.
Heat pump fan coils can be used with cooling-only con-
densing units to provide electric heat capability.
3. Unit mounting (outdoor)
a. Unit leveling — For reliable operation, units should be
level in all planes.
b. Clearance — Adequate clearance must be provided for
airflow. See dimensional drawings for proper clear-
ances. The condensing units are designed for free-blow
application. Air inlets and outlets should not be re-
stricted. Outdoor fan external static pressure available is
less than 0.1 in. wg.
c. Unit location — Cooling units can be stacked 2 high.
Units can be wall mounted, pad mounted at ground
level, roof mounted, or mounted on a deck or patio. Be
sure water drainage from roof will not drain directly onto
the unit.
NOTE: If stacking units, field-fabricated and installed hard-
ware is required. Contact your local representative for
drawings and details.
If 538S condensing units are being mounted near a wall,
the condenser air should discharge toward the wall. This
position provides inherent coil protection and the best pos-
sible sound and airflow performance.
4. Unit mounting (indoor)
a. Unit leveling — For reliable operation, units should be
level in all planes. The 619C ceiling-suspended fan coils
may have a slight pitch, but only toward the drain
connection.
b. Clearance — Provide adequate clearance for airflow.
The unit return and discharge should not be obstructed
by furniture, curtains, or anything which may cause unit
short cycling or air recirculation. See base unit dimen-
sional drawings on pages 15-19 for required clearances.
c. Unit location — When selecting unit location, select a
location which provides the best air circulation for the
room.
1) HIGH WALL UNITS — These units should be posi-
tioned as high as possible on the wall for best air cir-
culation. Allow adequate clearances above the unit
for servicing (removing unit covers). If possible, place
the unit in the middle (horizontally) of the wall se-
lected. Select an outside wall (if available) to make
piping easier, and place the unit so it faces the nor-
mal location of room occupants.
2) CEILING-SUSPENDED UNITS — These units
should be mounted near the ceiling and against a
wall. The unit should be centered (horizontally) on
the wall for best performance. Locating the unit on an
outside wall will make piping easier, but units can
also be mounted away from a wall if desired. (If the
unit is mounted away from a wall, the rear panel of
the unit may need a field-supplied trim strip for im-
proved appearance.) For quietest operation, locate
the fan coil return over an area which is not normally
occupied. Do not block air discharge for a minimum
of 15 ft to prevent dumping of cold air and drafts.
3) IN-CEILING CASSETTE UNITS — These units
should be mounted in the ceiling, preferably near the
center of the room. If the unit must be mounted near
a wall, close the air discharge on the blocked side(s).
(Up to 2 sides may be blocked.) Locate the control
box away from the blocked side(s).
5. Mounting template
The 619C fan coil units are furnished with a mounting tem-
plate to mark the location of the mounting brackets, wiring,
and refrigeration hole locations. In addition, the 619C units
indicate the location of ventilation-air connections.
6. Support
Adequate support must be provided to support the weight
of all fan coils. Refer to the Physical Data section on
page 11 for fan coil weights, and the base unit dimensional
drawings on pages 15-19 for the location of mounting
brackets.
7. System operating conditions
Operating limits:
OUTDOOR CONDENSING UNITS
TEMPERATURE CONDITION 538S
Maximum Cooling Ambient (F) 125
Minimum Cooling Ambient (F) –20
Minimum Cooling Return-Air Temperature (F) 55
Maximum Cooling Return-Air Temperature (F) 95
Maximum Compressor Discharge
Temperature (F)
275
Minimum Discharge Superheat (F) 60
FAN COIL UNITS
TEMPERATURE CONDITION 619C 619E 619F
Maximum Room
Temperature (F)
84 84 95
Minimum Room
Temperature (F)
64 64 55
Maximum Return Air (F)
Dry-Bulb 85 85 85
Wet-Bulb 72 72 72
Maximum Saturated
Suction Temperature (F)
55 55 55
Minimum Saturated
Suction Temperature (F)
27 27 27
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