31/10/2019
VACUUM LEAK DETECTOR
VLXE ..
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7.3.4 Check of the switching values with test equipment (Accessories section)
(1) Connect test device to a free nozzle on each of three-way valves
20 and 21.
(2) Connect measuring instrument to the T-piece of the test device.
(3) Close the needle valve of the test device.
(4) Turn three-way valve 20 by 90° (counter-clockwise) and three-
way valve 21 by 90° (clockwise), to shut off the interstitial space.
The interstitial space volume will now be simulated by the test
container.
(5) The operating vacuum will now be built up in the test container.
(6) Slowly vent using the needle valve; determine the switching val-
ues for "Pump ON" and "Alarm ON" (visual and, if appropriate,
audible). Note values.
(7) If appropriate, activate “Acoustic alarm” switch.
(8) Slowly close the needle valve and determine the switching values
for "Alarm OFF" and "Pump OFF".
(9) The test is considered to have been passed if the measured
switching values are within the indicated tolerance range.
(10) Turn back three-way valves 20 and 21 and remove test device.
7.3.5 Testing of the conveying height of the pump
The testing of the pump conveying height is carried out in order to de-
termine whether the vacuum source is able to create the operating
vacuum in the interstitial space.
(1) Connect test measuring instrument to the spout of the three-way
valve 20 and rotate the cock by 90° (counter-clockwise).
(2) Generally, the pump is not running at this time, i.e. the pressure
sensor must be ventilated to start the pump.
(3) Rotate three-way valve 21 (clockwise) by 90°. The pressure sen-
sor is ventilated, the pump start (and the alarm is triggered,
acknowledge if necessary).
(4) This test is considered as passed when the suction height of the
vacuum source is at least 40 mbar higher than the "Pump OFF"
switching value, i.e. the operating vacuum.
(5) Turn valves back after the test has been carried out and remove
measuring instrument.
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Functional check and maintenance