Mitsubishi MELSEC-WS series, User Manual

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Chapter 11
90
Maintenance
11.2 Device replacement
A critical fault in a MELSEC-WS module impairs the complete network. Devices that
have critical faults must therefore be repaired or replaced rapidly. We recommend
keeping spare devices of the MELSEC-WS modules at hand so that network
operation can be re-established as fast as possible.
Safety measures for replacing devices
Observe the following safety measures when replacing MELSEC-WS modules:

Do not try to dismantle or repair the MELSEC-WS modules. Not only does
Mitsubishi accept no claims for liability, but it is also dangerous as it makes
verifying the original safety functions impossible.
 Reset the device into a state in which safety is ensured.

Carry out replacement only when the voltage supply is switched off in order to
avoid an electric shock or unexpected device behavior.

In order to continue using the system configuration check:
– Is the new module of the same type (same material number) and is there no
error at the new module after the replacement?
– Is the new module plugged in at the same position as the replaced module?
– Have all connectors been re-connected to the correct terminals?
 Otherwise you have to completely reconfigure and commission the new system,
including all the necessary tests (see Chapter 9).
 After the replacement ensure that no errors arise with the new MELSEC-WS
modules.
 Always carry out a function test before commissioning a replacement module.
 SICK EFI-compatible devices do not have to be reconfigured after the
replacement of a MELSEC-WS module.
 If you send in MELSEC-WS modules for repair, generate a report on your project
and carry out diagnostics with the Setting and Monitoring Tool, enclose a detailed
description of the problem with the device and send the MELSEC-WS modules
with all available information to your local Mitsubishi representative.
Note