Inspection Of Explosion-Proof Devices; Pressure Switch; Master Valve; Pressurized Anti-Explosion Barrier - YASKAWA MOTOMAN-EPX1750 Instructions Manual

9 Maintenance and Inspection

9.4 Inspection of Explosion-Proof Devices

9.4
Inspection of Explosion-Proof Devices
9.4.1

Pressure Switch

Remove the front cover of the pneumatic unit box and check the conduction of the pressure switches.
The two pressure switches must be ON when the air is being supplied and OFF when the air is not
being supplied.
• Be sure to turn OFF the power to the NX100 before inspecting the pressure switch.
• Do not touch the pressure setting dial on the pressure switch during an inspection.
Changing the setting prevents the correct pressure from being detected.
9.4.2

Master Valve

While the air is being supplied from the pneumatic unit, check if the air purge starts a few seconds after
the power to the NX100 is turned ON. Also, check if the air goes out of the two air outlets for the master
valve during the air purge.
9.4.3

Pressurized Anti-Explosion Barrier

While the air is being supplied from the pneumatic unit, check if the air purge starts a few seconds after
the power to the NX100 is turned ON and if it ends approximately 8.5 minutes later.
Also, check the following:
(a) The alarm "AIR PRESSURE ERROR" occurs immediately after the air supply from the
pneumatic unit is stopped and the power supply to the NX100 is turned ON.
(b) The alarm "AIR PRESSURE ERROR" occurs when the air supply from the pneumatic
unit is stopped during air purging.
CAUTION
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