12
Maintenance and Replacement
Warning
This equipment contains a potential hazard of electric shock or burn. Only personnel
who are adequately trained and thoroughly familiar with the equipment and the
instructions should install, operate, or maintain this equipment.
12.1
Maintenance
Caution
Do not use compressed air to clean the boards. The compressed air may contain
moisture that could combine with dirt and dust and damage the boards. If the
compressed air pressure is too strong, components could be blown off the boards or
delicate solder runs could be damaged.
12.1.1
Terminal Boards and Cables
The control system should be inspected every 30000 hours (3.4 years) to ensure the components are functioning properly.
This inspection should include, but is not limited to terminal boards and cables.
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To clean terminal boards:
remove the dirt and dust from the boards using a grounded, natural bristle drapery brush or
paint brush.
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To clean cables:
remove dirt and dust with a lint free cotton cloth.
12.1.2
Ethernet Switches
The UDH, PDH, and IONet use fast Ethernet switches that are pre-configured specifically for the control system. Any
replacement switch must also be configured with the appropriate configuration for the controls application. Redundant
switches provide multiple communications links to the controllers and HMI systems.
Some basic troubleshooting techniques are useful in the diagnosis and repair of these systems as follows:
In the event of a network link failure, check the status LEDs at both ends of the link. Unlit LEDs indicate a failure in that
specific link. Troubleshoot the switch, cable, HMI, or controller by substituting known working Ethernet components until the
link status LEDs display health.
On large systems, there may be many switches. It will be necessary to pursue a half-interval (binary search) technique when
troubleshooting the network system. This half-interval approach involves isolating different local areas of the network by
removing the cables between different areas. These individual areas can then be diagnosed using the method described above.
Once all of the individual areas are functioning, they can be connected one at a time until the complete network is restored.
Maintenance and Replacement
GEH-6855_Vol_II System Guide 477
Public Information