Product data

APPLICATION DATA
1. Unit selection
Select equipment to either match or be slightly less than an-
ticipated 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 which has outdoor air intro-
duced 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 dry-bulb and wet-bulb conditions with the required out-
door air to select the proper equipment.
2. Unit combinations and coil mixed matches
The 538C and 538A units are the only units approved for
use with the 619E, 619C, and 619F fan coil units. The 538C
and 538A units can also be used with other fan coil units.
Mixed matches of indoor-fan coil capacity more than one
size larger than the outdoor condensing unit capacity may
result in inadequate indoor comfort. Do not select mixed
matches where the indoor-fan coil capacity is more than
one size larger than the outdoor condensing unit capacity
unless specifically indicated in this data. Heat pump fan
coils can be used with cooling-only condensing units to pro-
vide 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 may be stacked 2 high.
Units may be wall mounted, pad mounted at ground
level, roof mounted, or mounted on or under a deck or
patio. Be sure water from roof does not drain directly
onto the unit.
See your factory representative for drawings to con-
struct stacking rails or wall mounting brackets.
If 538A condensing units are being mounted near a wall,
the condenser air should discharge toward the wall. This
will provide inherent coil protection and the best possible
sound and airflow performance. The 538C units should
be mounted with fan discharge pointing away from the
wall.
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 con-
nection.
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 13-19 for required clearances.
c. Unit location — When selecting unit location, select a
location which will provide the best air circulation for the
room.
1) 619E HIGH WALL UNITS — These units should be
positioned as high as possible on the wall for best air
circulation. Allow adequate clearances above the unit
for servicing (removing unit covers). Place the unit in
the middle of the wall selected (if possible). Select an
outside wall if available to make piping easier, and
place the unit so it faces the normal location of room
occupants.
2) 619C CEILING-SUSPENDED UNITS — These units
should be mounted near the ceiling and against a
wall. The unit should be centered in the room 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 improved appearance.)
Locate the fan coil return over an area which is not
normally occupied for quietest operation. Do not
block air discharge for a minimum of 15 ft to prevent
dumping of cold air and drafts.
3) 619F 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 and 619E fan coil units are furnished with mount-
ing templates or mounting plates to mark the location of the
mounting brackets, wiring, and refrigeration line hole loca-
tions. 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 Specifications section on
page 6 for fan coil weights, and the base unit dimensional
drawings on pages 13-19 for the location of mounting
brackets.
7. System operating conditions
Operating limits:
OUTDOOR CONDENSING UNITS
CONDITION 538A 538C
Maximum Cooling Ambient (F) 125 125
Minimum Cooling Ambient (F) (without
accessory low-ambient kit)
55 55
Minimum Cooling Ambient (F) (with
accessory low-ambient kit)
–20 –20
Minimum Cooling Return-Air Temperature (F) 55 55
Maximum Cooling Return-Air Temperature (F) 95 95
Saturated Suction Temperature Range
Minimum (F) –15 –15
Maximum (F) 55 55
Saturated Condensing Temperature Range
Minimum (F) 80 85
Maximum (F) 150 150
Maximum Compressor Discharge
Temperature (F)
275 275
Minimum Discharge Superheat (F) 60 60
41