Product data

APPLICATION DATA (cont)
b. Long-lines applications, 538A units:
1) Liquid lines on all 538A units should be
3
⁄ 8 in. only.
DO NOT resize liquid lines for additional length.
2) When sizing vapor line, determine line length by find-
ing equivalent ft of pipe. Equivalent line lengths
equal the linear length (measured length) of the in-
terconnecting vapor tubing plus losses due to elbows
(see Fitting Loss in Equivalent Ft For Elbows table
on page 44). If the number of elbows is not yet
known, assume 50% additional length for equivalent
length. In determining line size, be sure oil can be
properly returned to the compressor. For line lengths
from 25 to 49 ft, no special piping requirements are
normally required. Adjust charge to required amount
by adding charge per Step g) on page 45 and check-
ing superheat.
3) For line lengths over 50 ft:
a) A crankcase heater should be added to scroll
compressor units (all non-scroll compressor units
have crankcase heaters as standard). Crankcase
heaters help prevent refrigerant migration to the
compressor during the off cycle.
b) Any time the equivalent line length is over 100 ft,
a liquid line solenoid must be used. A liquid line
solenoid may also be required for vertical lift ap-
plications over 25 ft. See Step f) on page 45.
c) A field fabricated accessory wind baffle is
recommended.
d) The Effective Capacity Loss table on page 44
provides the estimated percentage of nominal
cooling capacity losses based on the standard re-
quired vapor line size versus what is selected for
long-line applications.
Select the desired vapor line size from the Effec-
tive Capacity Loss table based on equivalent ft
and desired vapor line size.
Subtract the nominal percentage loss from the
unit cooling capacities for the given indoor and
outdoor combination.
SYSTEM PISTON GUIDE AND REFRIGERANT CHARGES
SYSTEM
TYPE
INDOOR
UNIT
OUTDOOR
UNIT
PISTON REQUIRED
(Size)
CHARGE
(Lb)*
High Wall
619E009 538C009 None† 1.5
619E012 538C012 None† 1.8
619E018 538A018 49 4.6
619E024 538A024 57 5.3
Ceiling Suspended
619C018** 538A018 53 3.7
619C024 538A024 57 5.5††
619C036 538A030 65 5.6
619C036 538A036 70 5.4
619C048 538A048 84 7.4
619C060 538A060 93 13.6
Ceiling Suspended
With Electric Heat
619C0180W0** 538A018 52 3.6
619C0240W0 538A024 53 6.2††
619C0360W0 538A030 63 5.6
619C0360W0 538A036 65 5.6
619C0480W0 538A048 84 7.4
619C0600W0 538A060 93 13.6
In-Ceiling Cassette
619F024 538A018 52 4.8††
619F036 538A024 62 5.2††
619F036 538A030 63 5.2
619F036 538A036 65 6.0††
In-Ceiling Cassette
With Electric Heat
619F0240W0 538A018 52 5.8††
619F0360W0 538A024 62 4.8
619F0360W0 538A030 63 5.2
619F0480W0 538A036 67 5.8
*Charge based on 25 ft of interconnecting tubing. Charge may need to
be added for longer tubing runs or when used with certain fan coils.
Check unit nameplate for required charge.
†Capillary tube located in the outdoor unit.
**The 018 size unit shown is a reconfigured 024 size unit. Refer to unit
Installation Instructions.
††Combination may require additional charge.
NOTES:
1. All pistons are Chattleff ‘‘B’’ type.
2. All cooling units have a full factory charge.
3. Service valves are front-seating type.
43