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Refrigeration Maintenance
118
Set Up and Test of Evacuation
Equipment
NOTE: See the previous two pages for the
following discussion.
1. Connect the evacuation system to a 110 Vac
power supply. Connect a gauge manifold and
refrigerant supply to the fitting above valve
V-4. Turn the micron gauge On.
2. Close valves V-1, V-3 and V-4. Valve V-2 is
open.
3. Turn the vacuum pump On.
4. Open valve V-1 at the pump. The micron
gauge needle will move to the left. (See
micron gauge scale diagram—previous page).
NOTE: If the vacuum pump is okay, and
there are no leaks between V-1 and V-3, the
micron gauge should show less than 500
microns. If not, locate and correct the
problem.
5. With the pump still operating, open valve V-3.
If the micron reading does not return to a level
of less than 500 microns, locate and correct
the problem before continuing.
6. With the vacuum pump still operating, open
valve V-4. The micron level will rise
momentarily. If the micron reading does not
return to a level of less than 500 microns,
locate and correct the problem before
continuing.
Figure 44: Leak
•
Isolate the pump from the system by closing
the proper valve. Watch the movement of the
vacuum gauge needle. If the needle continues
to rise, this is an indication that a leak exists in
the unit or the connecting line. The leak must
then be located and eliminated.
Figure 45: Moisture
•
Should the needle show a pressure rise but
finally level off to practically a constant mark,
this is an indication that the system is vacuum
tight but is still too wet, requiring additional
dehydration and pumping time.
7. Evacuate hoses to 100 microns or lowest
achievable level below 500 microns.
8. Once 100 microns is reached, close valve V-1
at the pump. Turn the vacuum pump Off.
9. Observe the micron gauge reading. The
vacuum rise should not exceed 1500 microns
in 5 minutes.
10. If the rise is above 1500 microns in 5 minutes,
check all hoses and connections for leaks.
Hoses with moisture present will require
additional evacuation time to achieve
satisfactory results.
NOTE: Dirty vacuum pump oil or a defective
vacuum pump will prevent a low micron
reading. Hoses and fittings can be isolated
individually to identify leaks.
Time
P
res
sur
e
Ri
se
Con
st
ant P
ressure
Rise
Leak
Time
P
res
su
re
R
ise
Pr
essure
Rise
Levels Off
Moisture
Summary of Contents for 914970
Page 3: ...3...
Page 10: ...Table of Contents 10...
Page 40: ...Operating Instructions 40...
Page 82: ...Electronic Controls 82...
Page 92: ...Electrical Maintenance 92...
Page 124: ...Refrigeration Maintenance 124...
Page 140: ...Hilliard Clutch Maintenance 140...
Page 160: ...Refrigeration Diagrams 160...
Page 163: ...Index 163 W wiring 85 wiring diagrams 165...
Page 164: ...Index 164...
Page 166: ...Wiring and Schematic Diagrams Index 166...
Page 167: ...167 Cab Control RD Wiring Diagram...
Page 168: ...168 RD w o Thermostat Cab Control Schematic...
Page 169: ...169 RD Cab Box Wiring Diagram...
Page 170: ...170 RD Cab Control w Thermostat Schematic Diagram...
Page 171: ...171 RD 50 STD 3 Phase Wiring Diagram Page 1 of 2...
Page 172: ...172 RD 50 STD 3 Phase Wiring Diagram Page 2 of 2...
Page 173: ...173 RD 50 STD 3 Phase Schematic Diagram Page 1 of 2...
Page 174: ...174 RD 50 STD 3 Phase Schematic Diagram Page 2 of 2...
Page 175: ...175 RD 30 STD Wiring Diagram Page 1 of 2...
Page 176: ...176 RD 30 STD Wiring Diagram Page 2 of 2...
Page 177: ...177 RD 30 STD Schematic Diagram Page 1 of 2...
Page 178: ...178 RD 30 STD Schematic Diagram Page 2 of 2...
Page 179: ...179 RD 30 C S Wiring Diagram Page 1 of 2...
Page 180: ...180 RD 30 C S Wiring Diagram Page 2 of 2...
Page 181: ...181 RD w CYCLE SENTRY Schematic Diagram Page 1 of 2...
Page 182: ...182 RD w CYCLE SENTRY Schematic Diagram Page 2 of 2...
Page 183: ...183 RD 50 C S 3 Phase Wiring Diagram Page 1 of 2...
Page 184: ...184 RD 50 C S 3 Phase Wiring Diagram Page 2 of 2...
Page 185: ...185 RD w CYCLE SENTRY Schematic Diagram Page 1 of 2...
Page 186: ...186 RD w CYCLE SENTRY Schematic Diagram Page 2 of 2...