Zanotti Zer0 120, Руководство по ремонту

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30
NOTE
: If the system will not come down to 500
microns, there is probably a leak in the system or in the
evacuation and charging equipment hoses. Find and
repair the leak.
4.6 CHARGING THE REFRIGERATION SYSTEM
Refrigerant R404a is a blend. Charging as a vapor will
change the properties of the refrigerant. Only liquid
charging is acceptable.
The liquid line sight glass helps the operator to
determine the amount of charge. These units can be
damaged by an overcharge of refrigerant.
The most satisfactory method of charging the circuit is as
follows:
1. After evacuation of the system is done and
manifold gauge valves are closed. Remove
vacuum pump from service hose
2. Connect the service hose of the gauge
manifold to the refrigerant bottle.
3. Place bottle on scale and "Tare" to 0.0lbs
4. For 404a make sure bottle is flipped upside
down to ensure the blend enters as a liquid
5. Open refrigerant bottle
6. Bleed center hose at manifold until all air is
out and you start to see liquid refrigerant.
Tighten immediately once liquid refrigerant
is seen. This is a negligible amount of
refrigerant.
7. While unit is off, open both gauge valves to
allow refrigerant to enter the system until
refrigerant equalizes. Ensuring that you do
not overcharge the unit initially. Watch the
weight scale.
8. Close both gauge manifold valves and turn
unit on
9. Slowly open low side gauges valve to
continue charging. Control the liquid flow so
the suction pressure increases approx. 20
PSIGg over running PSIGg.
10. Observe the liquid line sight glass. Close the
gauge manifold valve when the bubbles
disappear from the sight glass and scale
shows appropriate weight. (
NOTE:
Units
with longer hose sets running between
condensing section and evaporator section
may take more refrigerant charge.
11. Close refrigerant bottle
12. Close high side service valve or remove low
loss fitting from port.
13. Open both manifold gauge valves allowing
the high side to equalize with the low side
14. Close both gauge valves
15. Remove gauges after checking system
operation
Figure 13- Refrigeration Gauge Connection