Scotsman CME506R AutoIQ - Manual (Page 40)

Access Valves:
To use the access valves:
1. Be sure that the valve is closed. Remove the
stem cap and insert a 3/16" allen wrench. Check
that the valve is closed.
2. Remove the port cap and attach refrigerant
manifold hoses.
3. Open the valve and purge the hoses.
4. When service is complete, shut the discharge
access valve first. Then, with the machine running
and the middle hose outlet securely fastened to
the manifold or refrigerant tank (closed) open both
manifold valves. This allows any liquid refrigerant
in the discharge hose to flow thru the manifold and
into the suction side.
5. After the gages have equaled, shut the manifold
valves and the suction access valve.
6. Remove the gages and replace the stem and
port caps. Make certain that they are tightly closed.
Liquid Charging
Because R-404A is a near-azeotrope, only liquid
refrigerant can be used to recharge the
refrigeration system. To do that may take some
special techniques:
1. Use an electronic scale to measure the charge.
2. Place a drum or cylinder of R-404A on the
scale, valve side up (R-404A disposable cylinders
have an internal dip tube and dispense liquid
refrigerant from the valve when it is upright).
3. A refrigeration manifold should be attached to
the service access valves. Attach the charging
hose to the cylinder of R-404A. Open the cylinder’s
valve and purge the hose to the manifold.
4. Close the low side service access valve.
5. Open the discharge side manifold valve and
weigh in the name plate charge. After the charge is
weighed in, wait a few minutes and re-check the
scale.
6. If all of the refrigerant charge has not been
weighed into the discharge side, it must be
carefully added thru the low side. Close the
discharge service access valve.
7. With a sight glass or charge faster in the hose to
the low side port, start the ice machine.
8. Open the low side service access valve.
9. Crack open the low side manifold valve and
watch the scale and sight glass. Open and close
the low side manifold valve to flow liquid into the
manifold but flash off to vapor before it enters the
suction side of the refrigeration system. This
should only be a few ounces at most.
10. After the scale = the correct charge, shut off
the valve on the refrigerant cylinder.
11. With the ice machine running and the
discharge access valve closed, open both manifold
valves to allow the refrigerant in the hoses to enter
the system.
12. Shut the suction service access valve.
13. Remove the refrigeration manifold gages.
14. Replace and tighten all caps.
CME506R, 656R, 806R: AutoIQ Cubers
January 2000
Page 40
Allen
Wrench
Torque Stem
to 6-8 ft. lb.
Torque Stem Cap to
8-12 ft. lb.
Torque Core Cap
to 7-12 ft. lb.
Access Valve