Specifications
APPLICATION DATA (cont)
8. Low-ambient operation
Units can operate in cooling mode down to 55 F under all
conditions.
Units intended for operation in cooling mode below 40 F
should also be equipped with accessory crankcase heater,
accessory winter start kit, and field fabricated and installed
wind baffle.
a. Winter start (accessory) — Winter start bypasses the
low-pressure switch for 3 minutes. Use when cooling op-
eration in outdoor ambient temperatures below 40 F is
anticipated.
b. Crankcase heater (accessory) — Use when cooling
operation at outdoor ambient temperatures below 40 F
is anticipated.
9. 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 accessory condensate pumps havea3to25ftlift,
and all other fan coil units have a lift capability of 20 in.
above the condensate pan level.
See base unit dimensional drawings on pages 15-19 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 can be routed through alternate loca-
tions on most fan coils. See base unit dimensional drawings
on pages 15-19 for possible alternate locations.
Electric heat — The under-ceiling cooling systems can
provide electric heat by using the heat pump version of the
fan coil unit. Also, any unit with a condensate pump must
have a jumper wire installed between terminals O and Y on
the fan coil unit low-voltage terminal strip. Refer to the heat
pump Product Data literature for appropriate fan coil elec-
trical data.
10. Refrigerant lines
General refrigerant line sizing:
a. All charges, line sizing, and capacities are based on
runs of 25 ft. For runs over 25 ft, consult 538S Units sec-
tion on this page for proper line sizing and charge.
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 —
FAN COIL BELOW
CONDENSING
UNIT
MAXIMUM LIFT —
FAN COIL ABOVE
CONDENSING
UNIT
538S 50 30* 30*
*Maximum distance permitted is 30 ft from lowest system component to
highest system component.
b. 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.
c. Both liquid vapor lines must be insulated. Use a mini-
mum of
1
⁄
2
-in. thick insulation. Closed-cell insulation is
recommended in all long-line (over 25 ft) applications.
d. Special consideration should be given to isolating inter-
connecting tubing from the building structure. Isolate the
tubing so that vibration or noise is not transmitted into
the structure.
538S Units:
a. The 538S units are shipped with a full charge of R-22 re-
frigerant. Charge is based on 25 ft of line.
b. Filter driers are provided in the unit.
c. Two-phase supply lines on all 538S units should be
3
⁄
8
in. only. DO NOT resize supply lines for additional
length.
d. Vapor return line size is
5
⁄
8
in. for all applications.
11. Controls
The 619E fan coil units are controlled by wireless remote
controls. The 619C and 619F fan coil units must be hard-
wired only.
Wired 24-v Controllers (619C, 619F)
a. A 24-v thermostat is supplied for operation of all in-
ceiling and cassette systems.
b. Controller can only operate one unit, and a controller is
required for each unit.
c. The control must be located in the space being
conditioned.
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