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Table 2
REFRIGERANT
12, 134a, 513A
401A
22, 502, 407A, 407F, 448A, 449A
404A, 507, 402A
Table 3
Capacities are based on 0°F Evaporator, 94°F Condenser, 10°F Subcooled Liquid;
180 psig for 407A / 407F / 448A / 449A; 210 psig for 404A / 507
PRESSURE
DROP ACROSS
VALVE
(PSI)
5
10
20
The LAC-4 Liquid Flow capacities are equal to the above hot gas flow capacities (at 5 psi ∆P) at less than
two psi pressure drop.
WARNING:
Serious injury could result from an explosion caused by the rapid expansion
of trapped liquid refrigerant subjected to high temperature. Always open or vent the sys-
tem before applying heat to remove system components. Break the element charging
cap tube on valve dome by hand or with a clean cut tool. Do not use side cutters which may
seal the opening.
Figure 3
SERVICE INSTRUCTIONS
There are several possible causes for system malfunction with "refrigerant side" head
pressure control and these may be difficult to isolate from each other. As with any form
of system trouble-shooting, it is necessary to know the existing operating temperatures
and pressures before system problems can be determined. Once the actual malfunction
is established, it is easier to pinpoint the cause and then take suitable corrective action.
The following chart lists the most common malfunctions, the possible causes, and the
remedies.
LOW AMBIENT (Winter) CAPACITIES - TONS
Valve Setting of 100 psig for R-134a / 513A;
134a / 513A
MINIMUM AMBIENT DESIGN TEMPERATURE °F
-20
0
20
2.9 3.1 3.5 3.4 3.6 3.9 3.7 4.0 4.3 2.5 2.6 2.9
4.0 4.3 4.8 4.7 5.0 5.5 5.2 5.6 6.1 3.5 3.7 4.0
5.4 5.9 6.6 6.5 7.0 7.6 7.2 7.7 8.4 4.8 5.1 4.9
LAC
COMPRESSOR
RECOMMENDED SETTINGS (PSI)
REFRIGERANT
448A / 449A
-20
0
20
-20
CONDENSER
100
120
180
210
407A / 407F
0
20
-20
RECEIVER
SD-134 / Page 3
404A / 507
0
20
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