Product data

APPLICATION DATA (cont)
FAN COIL UNITS
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
55 55 55
Suction Temperature (F)
Minimum Saturated
Suction Temperature (F)
27 27 27
8. Low-ambient operation
Units can operate in cooling down to 55 F under all condi-
tions without a low-ambient kit.
Units equipped with accessory low-ambient kits should also
be equipped with accessory wind baffle, crankcase heater,
and winter start kit.
a. Winter start — The use of a winter start control may ex-
tend the operation range (generally to 35 F or 40 F) with-
out addition of the low-ambient kit. Winter start
bypasses the low-pressure switch for 3 minutes, and is
not required on 538C units.
b. Crankcase heater — Scroll compressor units with low-
ambient control should be equipped with crankcase
heaters to prevent refrigerant migration during compres-
sor off cycle.
9. Metering devices
a. 538C units — The 538C units have capillary tubes for
refrigerant metering located in the outdoor condensing
unit. These units may only be used with 619E fan coils of
the same size.
b. 538A units — The 538A units use a piston-type meter-
ing device located in the indoor unit.
NOTE: All duct-free split systems use Type ‘‘B’’ Chattleff
style AccuRaterT pistons. DO NOT mix Type ‘‘A’’ and
Type ‘‘B’’ pistons. See Long-Lines Applications section
(12.b) on page 43 for changes in piston sizes due to
long lines.
10. Drain connections
Install drains to meet local sanitation codes. If adequate
gravity drainage cannot be provided, unit should be
equipped with accessory condensate pump. High wall fan
coil unit condensate pumps havea1to10ftlift (009 size)
or 3 to 25 ft lift (012-024 sizes). All other fan coil units have
a lift capability of 20 in. above the condensate pan level.
See base unit dimensional drawings on pages 13-19 for
drain locations and sizes.
NOTE: High wall fan coil units have internal condensate
traps. All other fan coil units require a field-supplied external
condensate trap.
Drain connections may be routed through alternate loca-
tions on most fan coils. See base unit dimensional drawings
on pages 13-19 for possible alternate locations.
11. Electric heat — The in-ceiling and ceiling-suspended sys-
tems can provide electric heat by using the heat pump
version of the fan coil unit. The DIP switch must be recon-
figured at the jobsite for proper operation. Also, any unit
with a condensate pump must have a jumper wire installed
between terminals O and Y on the low-voltage terminal
strip. Refer to the heat pump Product Data literature for ap-
propriate fan coil electrical data.
12. Refrigerant lines
a. General refrigerant line sizing:
• All charges, line sizing, and capacities are based on
runs of 25 ft. For runs over 25 ft (538A only), consult
long-lines section on page 43 for proper line sizing,
charge, and AccuRater refrigerant metering device
sizing.
NOTE: For runs less than 25 ft, some of the charge may
need to be removed to obtain the correct system super-
heat. The minimum line length should be 8 ft.
MAXIMUM LINE LENGTHS
UNIT
MAXIMUM
EQUIVALENT
FT
MAXIMUM LIFT— MAXIMUM LIFT—
FAN COIL BELOW FAN COIL ABOVE
CONDENSING CONDENSING
UNIT UNIT
538A 200 150 65
538C 35 30 16
• Refrigerant lines should not be buried in the ground. If
it is necessary to bury the lines, not more than 36 in.
should be buried. Provide a minimum 6-in. vertical rise
to the service valves to prevent refrigerant migration.
• The vapor line must be insulated. Use a minimum of
1
⁄ 2 -in. thick insulation. Closed-cell insulation is recom-
mended in all long-line applications.
• Special consideration should be given to isolating in-
terconnecting tubing from the building structure. Iso-
late the tubing so that vibration or noise is not
transmitted into the structure.
1) 538C UNITS
a) The 538C units are shipped with a full charge of
R-22 refrigerant. Check the charge using the
superheat method. Since all refrigerant lines are
on the low side of the system, it is not normally
necessary to add or remove charge.
b) The 538C units have mixed-phase refrigerant
flow in the liquid line. DO NOT install a filter
drier in the liquid line. The liquid line must be
insulated.
c) No line size changes should be made on 538C
units.
2) 538A UNITS
a) The 538A units are shipped with a full charge of
R-22 refrigerant. Charge is based on fan coil with
smallest charge and 25 ft of line. See System
Piston Guide and Refrigerant Charges table on
page 43 for system charges. Add additional
charge by weight as necessary and check the
charge with a superheat calculator.
b) For the 538A units, install the filter drier provided
with the unit in the liquid line. Use of a field-
supplied moisture indicator is also recommended.
42