"Camel" Liquid Ring Medical Vacuum
Medical Systems
4-2
4.2 Automatic Operation
Check automatic operation as follows:
a. Set the HAND-OFF-AUTO selector switch to the AUTO position on all the vacuum pumps.
b. Monitor the vacuum gauge and check that each vacuum pump starts when the vacuum reaches the low
vacuum setting of the vacuum switch. Refer to the table below for the correct switch settings. In a new
installation a bleed may need to be established on the system to properly cycle the pumps.
c. Check that each vacuum pump shuts off when vacuum reaches the high setting of the vacuum switch and
the minimum run timer has been satisfied.
(See the wiring schematic for recommended timer settings.)
d. For Duplex and Triplex systems, check that the vacuum pumps alternate each time a vacuum pump
starts.
e. Set the HAND-OFF-AUTO selector switch for each vacuum pump to OFF position. Bleed vacuum from
vacuum control tank.
Vacuum Switch Settings*
Setting - inches Hg Vacuum
Simplex System
Duplex System
Triplex System
For Operating
Vacuum of
19 in. Hg
Start Stop Start Stop Start Stop
Vacuum
Pump
#1
19 23 19 23 19 23
Vacuum Pump #2
-
-
17
21
17
21
Vacuum Pump #3
-
-
-
-
15
19
*
Settings can be field adjusted
4.3 Vacuum Switch Set Point Adjustments
The vacuum switch is set at the factory to the operating point(s) as stated on the wiring diagram supplied with the
unit. It is good practice to cycle the switch to determine actual operating points before proceeding with
readjustment. Refer to the illustration below for location of adjustment.
Adjusting Instructions
FIRST
- Adjust the range (screw “A”) to the
required cut-in vacuum setting. Turning the screw
clockwise lowers the cut-in and cut-out vacuum
settings equally.
SECOND
- Adjust the differential (screw “B”) to
the required cut-out vacuum setting. Turning the
screw counter-clockwise will increase the cut-out
vacuum setting only. Differential is the difference
between cut-in and cut-out settings.
