Safety Guidelines; Plan For Safety; Safety Techniques - Automation Direct DL405 User Manual

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Installation and Wiring

Safety Guidelines

Plan for Safety

Safety Techniques

WARNING: Providing a safe operating environment for personnel and equipment is
your responsibility and should be your primary goal during system planning and
installation. Automation systems can fail and may result in situations that can cause
serious injury to personnel or damage to equipment. Do not rely on the automation
system alone to provide a safe operating environment. You should use external
electromechanical devices, such as relays or limit switches, that are independent of
the PLC system to provide protection for any part of the system that may cause
personal injury or damage.
Every automation application is different, so there may be special requirements for
your particular application. Make sure you follow all National, State, and local
government requirements for the proper installation and use of your equipment.
The best way to provide a safe operating environment is to make personnel and
equipment safety part of the planning process. You should examine every aspect of
the system to determine which areas are critical to operator or machine safety.
If you are not familiar with PLC system installation practices, or your company does
not have established installation guidelines, you should obtain additional
information from the following sources.
•
NEMA — The National Electrical Manufacturers Association, located in
Washington, D.C., publishes many different documents that discuss
standards for industrial control systems. You can order these
publications directly from NEMA. Some of these include:
ICS 1, General Standards for Industrial Control and Systems
ICS 3, Industrial Systems
ICS 6, Enclosures for Industrial Control Systems
•
NEC — The National Electrical Code provides regulations concerning
the installation and use of various types of electrical equipment. Copies
of the NEC Handbook can often be obtained from your local electrical
equipment distributor or your local library.
S
Local and State Agencies — many local governments and state
governments have additional requirements above and beyond those
described in the NEC Handbook. Check with your local Electrical
Inspector or Fire Marshall office for information.
The publications mentioned provide many ideas and requirements for system
safety. We recommend following these regulations as a minimum. Using the
techniques listed below will further help reduce the risk of safety problems.
•
Orderly system shutdown sequence in the PLC control program.
•
System power disconnects (guard limits, emergency stop switches,
etc.).