Eaton Analogue Input module types MTLx541A/MTLx541AS

Installation

There are two particular aspects of safety that must be considered when installing the MTL4500 or MTL5500

modules and these are:

• Functional safety

• Intrinsic safety

Reference must be made to the relevant sections within the instruction manual for MTL4500 range (INM4500)

or MTL5500 range (INM5500) which contain basic guides for the installation of the interface equipment to

meet the requirements of intrinsic safety. In many countries there are specific codes of practice, together with

industry guidelines, which must also be adhered to.

Provided that these installation requirements are followed then there are no additional factors to meet the

needs of applying the products for functional safety use.

To guard against the effects of dust and water the modules should be mounted in an enclosure providing at

least IP54 protection degree, or the location of mounting should provide equivalent protection such as inside an

equipment cabinet.

In applications using MTL4500 range, where the environment has a high humidity, the mounting backplanes

should be specified to include conformal coating.

Maintenance

To follow the guidelines pertaining to operation and maintenance of intrinsically safe equipment in a hazardous

area, yearly periodic audits of the installation are required by the various codes of practice. In addition, proof

testing of the loop operation to conform with functional safety requirements should be carried out at the

intervals determined by safety case assessment.

Proof testing must be carried out according to the application requirements, but it is recommended that this be

carried out at least once every three years.

Refer to Appendix B for the proof testing procedure of the MTLx541A/AS and MTLx544A/AS modules.

Note that there may also be specific requirements laid down in the E/E/PE operational maintenance procedure

for the complete installation.

If an MTLx541A/AS and MTLx544A/AS module is found to be faulty during commissioning or during the normal

lifetime of the product, then such failures should be reported to the local MTL office. When appropriate, a Cus

tomer Incident Report (CIR) will be notified by Eaton to enable the return of the unit to the factory for analysis. If

the unit is within the warranty period then a replacement unit will be sent.

Consideration should be given to the service lifetime for a device of this type, which is in the region of ten

years. Operating an MTLx541A/AS and MTLx544A/AS module for longer than this period could invalidate the

functional safety analysis, meaning that the overall safety function no longer meets its target SIL. If high failure

rates of the MTL modules are detected, indicating that they have entered the ‘end of life phase’ of their service

life, then they should be replaced promptly.