Kold-Draft GB564AC - Minimum Refrigerant Charge; R-404 a Charge Calculation and Cautions

new 60 Series Service Manual.rev. 06.01.16.docx - 79 –
Minimum Total Charge Required
Note:
• The factory charge in dual-evaporator models is 168 oz (10.5 lb) R-404a.
• The maximum total system charge for dual-evaporators is 208 oz (13 lb) R-404a.
• The basic charge for a dual-evaporator model is 3 lb R-404a.
To determine the total charge, add the following to the basic charge below:
1. For each 10 feet of 3/8” O.D. liquid return tubing add 6 oz of R-404a.
2. For each 10 feet of ½” O.D. compressor discharge line >70
o
F add ½ oz R-404a.
3. For each 10 feet of ½” O.D. compressor discharge line <70
o
F add 11 oz R-404a (assume
that at least 15’ will be <70
o
F if not certain).
4. Use the following amounts of R-404a according to the condenser model and the MINIMUM
ambient temperature expected at the condenser:
RC214APV
+60
o
F
2.3 lb
+40
o
F
2.9 lb
+20
o
F
3.2 lb
0
o
F
3.3 lb
-20
o
F
3.5 lb
EXAMPLE: Calculate the minimum total system charge for a GB1060R Ice Maker with an
RC214APV (single-circuit, 2-ton) condenser and 30 feet of interconnecting tubing with -20
o
F
minimum condenser ambient temperature. The calculation would be as follows: 3 lb (basic
charge) + 16.5 oz (15’ of ½” O.D. discharge line at <70
o
F) + 0.75 oz (15’ of ½” O.D. discharge
line at >70
o
F) + 3.5 lb (flooded condenser at -20
o
F) = 121.25 oz (7.6 lb). The factory charge for
GB1060R models is 10.5 lb.
Caution:
• Do not exceed the specified maximum total system charge.
• Interconnecting lines over 50’ are not recommended.
• Lines must be pitched upward toward the condenser with no “droops” or traps.
Note: The compressor will start immediately when power is applied, regardless of the “On/Off” or
the "Make Ice/Clean" switch positions, if the low-side pressure is at or above the pump-down
controller cut-in setting and the high-pressure cutout is not open. Be sure that the compressor
stops when the low-side pressure is between 5 and 15 psig.