Removal and Replacement Procedures - Safety Considerations - PLAN AHEAD!
Table 35 - I/O Module Replacement
Step
Action
Removal or Insertion Under Power of an I/O module is an option, but if operating circumstances permit, disconnecting power from the rack is the preferred option. Plan and develop an action sequence before beginning the replacement procedure. Primary considerations include:
When replacing I/O module, the voltages to the modules must be disconnected at the field device before removing the terminal block from the module.
Loss of control/monitoring in a running process - Each signal at each of the terminals for an I/O module has a specific function. Any or all of the signals may be vital for safely controlling a process. Determine the functions of all signals to the modules and know the potential consequences of losing each. If possible, transfer control to alternate mechanisms; otherwise, bring the process to a safe and controlled shutdown.
1.
2.
3.
4.
5.
6.
7.
Disconnect all signals from power sources, using
If a
Loosen the captive screws at top and bottom of the module; loosening the screws will cause the terminal block to be partly extracted from the module connector. Remove the terminal block from the module.
Using the extractor loop on the cover on the module, pull the module from the slot as shown in the illustration at right.
As shown in the illustration, a long
Insert the screwdriver tip into the extraction tab on the front of the module cover, and rotate the screwdriver handle toward the back, using the top edge of the rack as a fulcrum.
Verify that the replacement module is of the proper type. Then, carefully insert it into the slot in the rack so as to make proper contact with the connector in the backplane.
Replace the terminal block on the module.
If the rack was
Revision 5 | HC900 Hybrid Controller Installation and User Guide | 151 |
9/03 |
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