EXPO D760-ET MiniPurge, Manual

Page: 21 / 52

ML548 | v11
Page
18
Expo Technologies UK
T: +44 (0) 20 8398 8011
E: sales@expoworldwide.com
Expo Technologies US
T: +1 (440) 247 5314
E:sales.na@expoworldwide.com
Expo Technologies China
T: +86 532 8906 9858
E: qingdao@expoworldwide.com
Relief Valve opens (continuously or intermittently)
System enters purging but purge indication does not occur
System begins purging but cycles fail to complete
Fault Location Cause Solution
Pressurized Enclosure Enclosure pressure is too high due
to CLAPS Regulator being open to
far. Adjust the CLAPS Regulator.
Relief Valve Unit Debris on the Relief Valve disk
allowing air to leak from the valve. Remove Relief Valve cover and clean
the valve disk.
Fault Location Cause Solution
Air Supply Insufficient flow rate due to
inadequate air supply pressure.
Often due to pressure drop in the
supply pipe. Static pressure of 4 barg must be
maintained during purge
• Check air supply pressure at the
inlet to the control unit.
• Ensure that the supply pipe bore is
suitable for the flow rate
Pressurized Enclosure Excessive leakage from the
pressurized enclosure. • Check around the enclosure while
purging is taking place.
• Total leakage at purge outlet valve
should not exceed 10% of purge
flow sensor setting.
• Check for leakage down cables and
conduit.
Pipe Work Tubing from Relief Valve flow
sensing point not airtight. • Ensure fitting nuts are tightened.
• Check for tube damage.
• Repair as necessary.
Relief Valve Unit Relief Valve opening during purge. • Check enclosure pressure on start
up is less than Relief Valve lift off
pressure.
MiniPurge Control Unit Flow sensor setting incorrect. • Check the pressure is correct on the
flow sensor.
Fault Location Cause Solution
Electronic Timer Time set to 00 • Reset timer to correct purge
time.
The intrinsically safe battery pack
is discharged • Replace as necessary.