envea STACK 602, Руководство пользователя

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9 Maintenance STACK 602
52
(PC-000848-MA Issue 5, December 2021)
ENVEA UK Ltd
9.4 Inspecting and Cleaning Procedures
The nature of many processes is such that a build-up of particulate may develop
on the sensor windows. This build-up will normally not affect the instrument's
performance, but it is recommended that the build-up is periodically removed. Put
the sensor in Maintenance mode (see page
50
). This will force 4-20mA outputs to
4mA and disable relays.
9.4.1 Cleaning the Sensor Window (Rx and Tx)
1. Undo the grub screws (4 off) connecting the sensor to the alignment fitting.
2. Clean the sensor window, then refit to the sensor and tighten the grub
screws.
3. Perform any other maintenance required at the sensor.
4. Ensure that the sealed connectors are secure and undamaged.
5. Inspect the connecting cables (where possible), ensure that they are not
damaged or stressed.
6. Check that no moisture or foreign bodies have entered the sensor unit
enclosure. Ensure that the cover lid is securely refitted.
9.5 Troubleshooting
WARNING! – HAZARDOUS VOLTAGES
The control unit contains lethal voltages!
Always switch OFF and isolate the unit from the power supply before
removing the front cover.
WARNING! – ELECTRIC SHOCK
Ensure that the mains isolator is easily accessible (within a 2 m/6½
ft. radius) to allow the control unit to be switched off.
9.5.1 Comms Failure
The control unit can support many sensors and devices that may be spread over
a wide area of a plant. It is, therefore, essential to be methodical in the approach
to locating the cause of communications problems. If you cannot get the complete
network to communicate, it is best to disconnect some of the sensors and add
them in one by one to see where the problem occurs.
Diagnostics
1. On the control unit, check that the Sensor Comms Mode is set correctly (see
section
7.2.1
on page
39
)
2. Run Autodetect and note which devices fail to be detected.
3. If existing devices have stopped communicating, this will show up as:
3a. A ‘No Response’ message at the bottom of the screen
3b. A flashing red LED
3c. On the QA/Self-Tests screen: Comms Check = ‘No Response’.