tailieunhanh - Industrial Automation Wiring and Grounding Guidelines

This publication gives you general guidelines for installing an Allen-Bradley industrial automation system that may include programmable controllers, industrial computers, operator-interface terminals, display devices, and communication networks. While these guidelines apply to the majority of installations, certain electrically harsh environments may require additional precautions. Use these guidelines as a tool for helping avoid potential electromagnetic interference (emi) and transient emi that could cause problems such as “adapter faults, rack faults, communication faults,” etc. These guidelines are not intended to supersede local electrical codes. This publication is organized into the following sections: • Raceway layout considerations • Mounting, bonding, and grounding. | Application Data Industrial Automation Wiring and Grounding Guidelines Purpose This publication gives you general guidelines for installing an Allen-Bradley industrial automation system that may include programmable controllers industrial computers operator-interface terminals display devices and communication networks. While these guidelines apply to the majority of installations certain electrically harsh environments may require additional precautions. Use these guidelines as a tool for helping avoid potential electromagnetic interference emi and transient emi that could cause problems such as adapte rf aul f aults com m uni cationf anlts etc. These guidelines are not intended to supersede local electrical codes. This publication is organized into the following sections Raceway layout considerations Mounting bonding and grounding Power distribution Surge-suppression Ferrite beads Enclosure lighting Avoiding unintentional momentary turn-on of outputs Related publications Publication - February 1998 2 Industrial Automation Wiring and Grounding Guidelines Raceway Layout Considerations The raceway layout of a system is reflective of where the different types of I O modules are placed in I O chassis. Therefore you should determine I O-module placement prior to any layout and routing of wires. However when planning your I O-module placement segregate the modules based upon the conductor categories published for each I O module so that you can follow these guidelines. Also all conductors ac or dc in the same raceway must be insulated for the highest voltage applied to any one of the conductors in the raceway. These guidelines coincide with the guidelines for theinstallationofelectricalequipmenttominimize electrical noise inputs to controllers from external sources inIEEE standard 518-1982. Categorize Conductors Segregate all wires and cables into the following three categories Table A . Refer to the publication for each specific I O module or block .