Fault Finding And Routine Maintenance; Maintenance Precautions; Fault Finding; Routine Maintenance - Eaton Crouse-Hinds Series Instruction Manual

INM 4500/4600 Rev 12
DRAFT - 22 March 2018
7

FAULT FINDING AND ROUTINE MAINTENANCE

On removal, take care that a hazardous-area connector is not laid in a position
in which it may inadvertently come into contact with the backplane or with
7 .1

Maintenance precautions

Most Codes of Practice for intrinsic safety permit live maintenance on intrinsically safe
devices and systems, provided precautions are taken to preserve the integrity of the device
or system. During live maintenance of MTL4500 modules, the hazardous-area connectors
that plug into the tops of the modules are likely to be removed. Avoid leaving a hazardous-
area connector in a position where it may inadvertently contact non-IS circuits that are
nearby. Prevent this by providing some form of temporary mechanical method of securing
the connector so that it cannot come into contact with the non-IS circuits:
d) By plugging the connector into an MTL4599 dummy isolator
e) By using a tiewrap to constrain the connector in a safe position.
7 .2

Fault finding

When fault finding, carry out the following steps as far as is necessary:–
7 .2 .1
Check that one of the backplane power LEDs is ON.
7 .2 .2
If a power LED is not on, check the power supply fuse and if necessary, change it. Ratings
are:–
f) 4/8-way backplanes 1A (Spare fuse kit FUS1.0ATE5)
g) 16-way backplanes 2A (Spare fuse kit FUS2.0ATE5)
h) 24/32-way backplanes 4A (Spare fuse kit FUS4.0ATE5)
7 .2 .3
Check that all modules with power (PWR) LEDs are ON.
With the MTL4532, MTLx573, MTL4575 & MTL4576 models, a flashing LED indicates alarm
or fault conditions - refer to section 8. Note: The LED may also flash during intermediate
stages of configuration.
7 .2 .4
Exchange potentially faulty modules for working units as follows:–
a) Unplug the hazardous-area connectors.
b) Unplug the module from the backplane.
c) Plug the replacement unit into the backplane.
d) Replace the hazardous-area connectors.
7 .2 .5
Potentially faulty modules should be tested in workshop conditions, using the following
procedure:–
a) Connect a power supply to a spare CPS backplane (refer to sections 4.4.2 or 4.4.4).
b) Plug the suspect module into any position on the backplane.
c) Carry out the appropriate test procedure described in Section 8 for the particular module.
7 .3

Routine maintenance

Check the general condition of the installation occasionally to make sure that no
deterioration has occurred. Carry out the following at least once every two years and more
frequently for particularly harsh environments:–
a) Check that modules are of the types specified in the relevant documentation and that
they are mounted in the correct positions on the associated backplanes.
b) Check that modules and hazardous-area connectors are correctly and legibly tagged,
that the connectors are plugged into the matching modules and that the tag details
given comply with the relevant documentation.
WARNING!
components on the backplane.
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