Endress+Hauser NAR 300, Руководство по эксплуатации

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Troubleshooting NAR300 system for high temperature
40 Hauser
7 Troubleshooting
7.1 Fail-safe (alarm is output when there is no oil leak)
There is a risk of an alarm being output due to the following causes even if there is no
actual oil leak.
Item Description
Frozen pit water An alarm is activated when the pit water freezes and the conductive sensor
recognizes it as an insulator.
Tilted float sensor When the conductive sensor is tilted so much that it is no longer submerged in
water while it is floating on pit water, an alarm is activated because it recognizes
insulating air.
Empty pit An alarm will always be activated in an empty pit.
Sensor buried in mud When the float sensor becomes buried in mud and the mud dries out and
hardens, an alarm is activated.
Essentially pure water in pit In pit water with a large electrical resistance value, such as drain water, the
conductive sensor detects it as an insulator, thereby activating an alarm.
7.2 Delayed alarm (alarm is not output when there is an
oil leak)
There is a risk of an alarm not being output due to the following causes even if there is an
oil leak.
Item Description
Waves and cross-currents
on the liquid surface If the oil layer and the pit water are not stable due to strong waves on the surface
of leaked oil caused by wind, etc., the conductive sensor will detect the pit water
and therefore will not activate the alarm.
Tilted float sensor When the float sensor tilts most of the way to one side due to snow, an animal
on the float sensor, or a cable/chain becoming tangled, the conductive sensor
detects the pit water under the oil layer and no alarm is issued.
Sunk float sensor If snow, garbage or an animal lands on the float, the float will sink and the
conductive sensor will detect the pit water under the oil layer, and no alarm will
be activated.
Moist garbage, etc. If moist garbage or algae comes in contact between the conductive sensor and
the earth (such as the float's main unit or the ground) and generates
conductivity, an alarm will not be activated.
Oil leak during snowfall If there is snow floating on the oil layer surface, the water from melted snow will
be recognized as water by the conductive sensor, and an alarm will not be
activated.
Oil leak during snowfall If there is snow floating on the oil layer surface, the water from melted snow will
be recognized as water by the conductive sensor, and an alarm will not be
activated.