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2.2.4 Safety Guidelines
This section presents recommended installation practices, and procedures. Since no two applications are identical, these
recommendations should be considered as guidelines.
Hardware
Considerations
WARNING!
The system designer should be aware that devices in Controller systems could fail and thereby
create an unsafe condition. Furthermore, electrical interference in an operator interface, such as an
HMI, can lead to equipment start-up, which could result in property damage and/or physical injury to
the equipment operator.
If you, or your company, use any programmable control systems that require an operator or
attendant, you should be aware that this potential safety hazard exists and take appropriate
precautions. Although the specific design steps depend on your particular application, the following
precautions generally apply to installation of solid-state programmable control devices. In addition,
these precautions conform to the guidelines for installation of Controllers as recommended in the
NEMA ICS 3-304 Control Standards.
Programming
Considerations
To conform with ICS Safety Recommendations, checks should be placed in the controller to ensure
that all writable registers that control critical parts of plant or machinery have limit checks built into the
program, with an out-of-limit safe shut down procedure to ensure safety of personnel.
ICS 3-304.81 Safety Recommendations:
Consideration should be given to the use of an emergency stop function, which is independent of the programmable
controller.
Where the operator is exposed to the machinery, such as in loading or unloading a machine tool, or where the
machine cycles automatically, consideration should be given to the use of an electromechanical override or other
redundant means, independent of the programmable controller, for starting and interrupting the cycle.
If provision is required for changing programs while the equipment is in operation, consideration should be given to the
use of locks or other means of assuring that such changes can be made only by authorized personnel.
These recommendations are intended as safeguards against the failure of critical components and the effects of such
failures or the inadvertent errors that might be introduced if programs are changed while the equipment is in operation. *
* The ICS 3-304.81 Safety Recommendations are reproduced by permission of the National Electrical Manufacturers
Association from NEMA ICS 3-304
2.3 CE Requirements
2.3.1 EU directives that apply to MMI Series
• EMC Directive (89/336/EEC, 92/31/EEC, 93/68/EEC) electromagnetic emissions and immunity
• Machinery Directive (89/392/EEC, 91/368/EEC, 93/44/EEC, 93/ 68/EEC) machine safety
MMI products are CE-marked to indicate compliance with the EMC Directive. Declarations of Conformity that
specify the directive(s) and the catalog numbers of the products covered are available from Kessler Ellis Products.
Summary of Contents for MMI-1500
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