ML442 | v5k
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Expo Technologies UK
T: +44 (0) 20 8398 8011
E: [email protected]
Expo Technologies US
T: +1 (440) 247 5314
E:[email protected]
Expo Technologies China
T: +86 532 8906 9858
E: [email protected]
We recommend that the setting of the minimum pressure sensor be checked at this time. Note
the position of the LCV knob. (A pencil mark placed on the knob at "12 O'clock” can be used).
Slowly lower the PE pressure by closing the LCV further, counting the number of turns from the
"normal working pressure" position. Note the pressure at which the "alarm/pressurized"
indicator turns from green to red and check that it is not lower than the figure given in the
documentation. Check also the "alarm" electrical contacts. As soon as the "alarm/pressurized"
indicator turns red, the system will start to re-purge. If Alarm and Trip function is selected the
enclosure power will be switched off.
While it is re-purging return the LCV to its "normal working pressure" position so that, at the end
of purging, the enclosure pressure should immediately settle down at the correct "normal"
pressure.
If, at the end of purging, the PE pressure falls below the minimum pressure sensor setting
and the LCV is fully open, the system will start to purge again. This is indicative of
excessive leakage from the enclosure. In this case, check the enclosure for leakage, and
reduce or eliminate the leaks. This time, at the end of purging, the enclosure should stay
pressurized and the RLV action is as in a) or b) above. Proceed as described above.
5.3 Normal operation
Turn the air supply on or off to start or stop the system. After this the pressurizing and purging
sequence is entirely automatic
