Chapter 2: Installation and Wiring
2–2
DL205 Installation and I/O Manual, 2nd Edition
Safety Guidelines
NOTE: Products with CE marks
perform their required functions safely and adhere to relevant standards as
specified by CE directives, provided they are used according to their intended purpose and that the
instructions in this manual are adhered to. The protection provided by the equipment may be impaired if
this equipment is used in a manner not specified in this manual. A listing of our international affiliates is
available on our Web site: http://www.automationdirect.com
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 and/or damage equipment. Do
not rely on the automation system alone to provide a safe operating environment. Sufficient emergency
circuits should be provided to stop either partially or totally the operation of the PLC or the controlled
machine or process. These circuits should be routed outside the PLC in the event of controller failure,
so that independent and rapid shutdown are available. Devices, such as “mushroom” switches or end
of travel limit switches, should operate motor starter, solenoids, or other devices without being
processed by the PLC. These emergency circuits should be designed using simple logic with a
minimum number of highly reliable electromechanical components. Every automation application is
different, so there may be special requirements for your particular application. Make sure all national,
state, and local government requirements are followed for the proper installation and use of your
equipment.
Plan for Safety
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.
• 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.
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