Application Techniques
Original Instructions
Industry Installation Guidelines for Pulse Width Modulated (PWM)
AC Drives
Industries discussed in this application technique include:
Automotive Marine and Offshore
Chemical/Specialty Chemical Mining and Steel
Food and Beverage Tire Manufacturing
Forest Products/Converting Water/Waste Water
Summary of Changes
This manual has been extensively revised to reduce redundancies in previous version. There are different requirements in applications for
specific industries. The unique requirements of the Marine Industry are in Chapter 4 Marine and Offshore Industry. Other industries which
have more in common are discussed in Chapters 1…3 and Appendix B: Sample Requirements and Enclosure Specifications for Specific
Industry Types, which provides bulleted lists of the requirements for each of these industries. These industries include:
• Automotive
• Forest and pulp paper products
•Metal products
• Mining process products
• Oil and gas products
• Open pit mining products
This manual contains new and updated information as indicated in the following table.
Top ic Pa ge
Updated Safety Information link in Degree of Protection section of Chapter 1 and in the
Additional Resources table.
Added Control System Packaging for Corrosion Mitigation Design and Installation Guideline,
publication TIRE-RM001 and Control System Packaging for Corrosion Mitigation White Paper,
publication WWW-WP001 to Additional Resources table.
Moved General Precautions from Preface to Chapter 2. 21
Consolidation of common information between industries into first three chapters rather
than spread across 10 chapters as in previous version
Moved Marine and Offshore Industry information from Chapter 7 in original document to
Chapter 4.
Creation of Sample Drive Installation Requirements Appendix to list standard drive
requirements.
Creation of Sample Requirements and Enclosure Specifications for S pecific Industry Types
Appendix to list unique requirements of cer tain industries.
10, 59
59
Var iou s
37
41
47
2 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Table of Contents
Preface
About This Publication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Who Should Use This Manual. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Recommended Agencies and Standards Publications. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
National Electrical Manufacturers Association (NEMA) . . . . . . . . . . . . . . . . . . . . . . . 5
Underwriters Laboratories, Inc. (UL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Canadian Standards Association (CSA). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
National Fire Protection Association (NFPA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
International Society of Automotive Engineers (SAE). . . . . . . . . . . . . . . . . . . . . . . . . 6
The Institute of Electrical and Electronics Engineers, Inc. (IEEE). . . . . . . . . . . . . . . 6
American Bureau of Shipping (ABS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
The International Society of Automation (ISA). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
International Electrotechnical Commission (IEC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Conventions Used in This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Chapter 1
Environmental Considerations General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Enclosure Types and Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
North American Standards Organizations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
International Standards Organizations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Degree of Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
IEC Enclosure Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Abridged Descriptions of IEC Enclosure Test Requirements. . . . . . . . . . . . . . . . . . . . . . 11
Tests for Protection Against Access to Hazardous Parts (first
characteristic numeral) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Tests for Protection Against Water (second characteristic numeral) . . . . . . . . . . 13
Abridged Descriptions of NEMA Enclosure Test Requirements. . . . . . . . . . . . . . . . . . . . 14
6.2 Rod Entry Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.3 Drip Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.4 Rain Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.5.1.1 (2) Outdoor Dust Test (Alternate Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.5.1.2 (2) Indoor Dust Test (Alternate Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
6.6 External Icing Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
6.7 Hosedown Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
6.8 Rust Resistance Test (Applicable Only to Enclosures Incorporating
External Ferrous Parts) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
6.9 Corrosion Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
6.11 (2) Air Pressure Test (Alternate Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
6.12 Oil Exclusion Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Abridged Descriptions of UL Standard 698 Test Requirements . . . . . . . . . . . . . . . . . . . 16
Explosion Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Hydrostatic Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Temperature Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Dust Penetration Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Temperature Test with Dust Blanket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Enclosure Type Descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 1
Table of Contents
Industry Related Installation
Considerations
Type 1 – General Purpose Surface Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Type 1 – Flush Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Type 3 – Rainproof Dusttight. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Type 3R – Rainproof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Type 4 – Watertight. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Type 4X – Non-metallic, Corrosion-resistant. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Type 6P – For Prolonged Submersion at a Limited Depth . . . . . . . . . . . . . . . . . . . . 18
Type 7 – For Hazardous Gas Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Type 9 – For Hazardous Dust Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Type 12 – Dusttight Industrial Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Type 13 – Oiltight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Enclosure Type Descriptions for Non-hazardous Locations. . . . . . . . . . . . . . . . . . . . . . 19
Enclosures Offered by Rockwell Automation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Chapter 2
General Precautions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Contaminants and Conditions by Industry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Environmental and Atmospheric Considerations by Location. . . . . . . . . . . . . . . . . 23
Explanation of Contaminant Severity Levels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Explanation of Contaminant Severity Levels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Relative Humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Duty Rating of the AC Drive Application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Periodic Duty Rating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Short-time Duty Rating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Non-periodic Duty Rating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Continuous Duty Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Protecting Electronic Modules From Contaminants. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Shielding by Enclosures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Source Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Ventilation Control and Removal Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Outdoor Installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Protecting Electronic Modules During Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Sources of Reactive Contaminants and Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Chapter 3
System Configurations,
Grounding, Application, and
Control
2 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Power Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
System Configurations and Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Delta/Wye with Grounded Wye Neutral. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Delta/Delta with Grounded Leg or Four-wire Connected Secondary Delta . . . . . . 32
Three-phase Open Delta with Single-phase Center Tapped . . . . . . . . . . . . . . . . . . 32
Ungrounded Secondary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
High Resistance Ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Application and Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Automotive Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Chemical and Specialty Chemical Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Food and Beverage Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Forest Products and Converting Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Mining and Steel Industry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Table of Contents
Tire Manufacturing Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Water and Waste Water Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Chapter 4
Marine and Offshore Industry Typical Environmental Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Typical Hazardous Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Shielding by Enclosures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Protecting Electronic Modules During Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Power Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
System Configurations and Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Ungrounded Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Ungrounded Secondary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Application and Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
System Design and Implementation Considerations . . . . . . . . . . . . . . . . . . . . . . . . 40
Appendix A
Sample Drive Installation
Requirements
Design Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Input Power Conditioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Grounding and Bonding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Motor Cable Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Encoder Feedback Signal Wiring – Rockwell Automation’s Recommended Shielding
Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Dynamic Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Wire Routing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Surge Suppression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Environmental Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Pre-Installation Checklists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
AC Supply SourceInput Power Conditioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Surge Suppression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Grounding and Bonding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Mounting Considerations and Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Control and Signal Cabling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Dynamic Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Motor Cable Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Encoder Feedback Signal Wiring – Rockwell Automation’s Recommended Shielding
Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Post Installation Checklists. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
AC Supply Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Input Power Conditioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Surge Suppression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Grounding and Bonding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Mounting Considerations and Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Control and Signal Cabling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Dynamic Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Motor Cable Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Encoder Feedback Signal Wiring – Rockwell Automation’s Recommended Shielding
Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 3
Table of Contents
Appendix B
Sample Requirements and
Enclosure Specifications for
Specific Industry Types
Automotive Industry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Enclosure Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Welded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Grounding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Frame and Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Forest Products/Converting (Pulp Paper Products) Industry . . . . . . . . . . . . . . . . . . . . . 48
Enclosure Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Welded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Frame and Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Gaskets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Marine and Offshore Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Metals Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Enclosure Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Welded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Frame and Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Gaskets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Mining Process Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Enclosure Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Welded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Frame and Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Gaskets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Oil, Gas, and Chemical Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Enclosure Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Welded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Frame and Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Gaskets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Temperature Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Open Pit Mining Products. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Enclosure Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Welded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Frame and Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Gaskets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Index
4 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Preface
About This Publication
The purpose of this application technique is to provide basic information for different enclosure systems and environmental/location
considerations (to help protect against environmental contaminants), and power and grounding considerations needed to properly install a
Pulse Width Modulated (PWM) AC drive. The industry-specific guidelines in this document are meant to be used as examples - specific
locations are unique and the guideline examples should be adapted accordingly.
Pulse width modulation is a form of control used to generate a waveform necessary to operate an induction motor. With PWM control it is
possible to change the speed of the motor by varying the frequency sent to the motor. PWM drives are also known as Variable Frequency
Drives, and Adjustable Speed Drives.
Who Should Use This Manual
This manual is intended for qualified personnel who plan and design installations of PWM AC drives.
Recommended Agencies and Standards Publications
The following agencies and standards publications provide general information for installing drives and drive enclosures in regards to
environmental conditions and degrees of protection against ingress of contaminants.
National Electrical Manufacturers Association (NEMA)
1300 North 17th Street
Suite 1847
Rosslyn, VA 22209, USA
www.nema.org
• NEMA Standards Publication No. 250, Enclosures for Electrical Equipment (1000 Volts Maximum)
• NEMA Standards Publication No. ICS6, Enclosures for Industrial Controls and Systems
Underwriters Laboratories, Inc. (UL)
333 Pfingsten Road
Northbrook, IL 60062, USA
www.ul.com
• UL 50 Enclosures for Electrical Equipment, Non-Environmental Considerations (Type 1)
• UL 50E Enclosures for Electrical Equipment, Environmental Considerations (Remaining Types)
• UL 94 Flammability of Plastic Materials
• UL 414 Meter Sockets
• UL 497 Protectors for Paired Conductor Communication Circuits
• UL 508A Industrial Control Panels
• UL 870 Wireways, Auxiliary Gutters and Associated Fittings
•UL 1203 Explosion-Proof and Dust-Ignition-Proof Electrical Equipment for Use in Hazardous (Classified) Locations
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 5
Preface
• UL 1773 Termination Boxes
• UL 1863 Communication Circuit Accessories
• UL 2279 Electrical Equipment for Use in CLI Zone 1 and 2 Hazardous Locations
Canadian Standards Association (CSA)
178 Rexdale Boulevard
Rexdale (Toronto), Ontario, Canada
M9W 1R3
www.csa.ca
CSA Standard C22.2:
• No. 0 General Requirements - Canadian Electrical Code, Part II
• No. 0.4 Bonding and Grounding of Electrical Equipment (Protective Equipment)
• No. 14 Industrial Control Equipment for Use in Ordinary (Non- Hazardous) Locations
• No. 25 Enclosures for Use in Class 11 Groups E, F, and G Hazardous Locations
• No. 26 Construction and Test of Wireways, and Auxiliary Gutters, and Associated Fittings
• No. 40 Cutout, Junction, and Pull Boxes
•No. 76 Splitters
• No. 94 Special Purpose Enclosures
• No. 182.4 Plugs, Receptacles, and Connections for Communications Systems
National Fire Protection Association (NFPA)
Batterymarch Park
Quincy, MA 02169-7471, USA
www.nfpa.org
• NFPA 70 National Electrical Code
• NFPA 70e Standard for Electrical Safety Requirements for Employee Workplaces
• NFPA 79 Electrical Standard for Industrial Machinery
• NFPA 496 Purged and Pressurized Enclosures for Electrical Equipment
International Society of Automotive Engineers (SAE)
400 Commonwealth Drive
Warrendale, PA 15096-0001, USA
www.sae.org
• SAE HS 1738 SAE Standard - Electrical Equipment for Automotive Industrial Machinery
The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
3 Park Avenue,
New York, NY 10016-5997, USA
www.ieee.org
• IEEE 45, Recommended Practice for Electrical Installations on Shipboard
6 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
American Bureau of Shipping (ABS)
ABS Plaza
16855 Northchase Drive
Houston, TX 77060, USA
www.eagle.org
• Rules for Building and Classing Steel Vessels 2009, Part 4, Vessel Systems and Machinery
The International Society of Automation (ISA)
67 Alexander Drive
Research Triangle Park, NC 27709, USA
www.isa.org
• ISA-71.04-2013, Environmental Conditions for Process Measurement and Control Systems: Airborne Contaminants
International Electrotechnical Commission (IEC)
Preface
3, rue de Varembé
P.O. Box 131
CH - 1211 Geneva 20 - Switzerland
www.iec.ch
• IEC Publication 529, contains descriptions and associated test requirements that define the degree of protection each IP numeral
specifies
• IEC Publication 60079, standard for installations in hazardous areas
• IEC Publication 60079-20, section for flammability group and temperature class of equipment installed in hazardous areas
• IEC Publication 60529, describes the complete test procedures for standard degrees of protection ratings
Conventions Used in This Manual
These conventions are used throughout this manual.
• Bulleted lists such as this one provide information, not procedural steps.
• Numbered lists provide sequential steps or hierarchical information.
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 7
Preface
Notes:
8 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Chapter 1
Environmental Considerations
This chapter describes environmental considerations, standards, and agency requirements for enclosures for different environments. This
is not meant to be a comprehensive guide but provide information that can let you know the different regulations that need to be further
studied and complied with for your location. Please contact your local Rockwell Automation representative for assistance in selecting or
addressing environmental concerns.
General Information
You must evaluate the environment where your AC drive will be installed, identify any contaminants, and provide the correct degree of
protection for the AC drive and electronics in either a stand-alone installation or when mounting the drive inside an enclosure. This
evaluation and degree of protection helps to make sure the drive functions correctly and reliably. If the drive is going to be placed into an
environmental setting that is harsher than defined by the specified rating of the drive, it must be installed in the proper type of protective
enclosure. If the drive is not installed in the proper type of protective enclosure it can suffer failure from atmospheric contaminants which
produce corrosion.
Corrosion failures of industrial electronic equipment is a concern, especially in industry groups such as water/waste water, paper making,
steel, and tire manufacturing. For these industries, sulfur compounds that can attack electrical components and lead to failure are typical.
These failures can be unexpected because the relatively low levels of sulfur concentration that can lead to electronic failure are often not
perceived as severe by workers in those facilities. Electronic assemblies can fail due to several corrosion mechanisms. This corrosion can
occur with or without electrical voltage being present, and can also compromise insulated systems, if and when they become conductive.
Conformal coating of printed circuit boards can prevent some of the contamination challenges faced in the field; but, because all
components are not coated, there is still a need to review the applications and environments. Refer to Conformal Coating for Variable Speed
Drives, publication DRIVES-WP021
.
Enclosure Types and Ratings
What's in an Enclosure Rating?
As a way of standardizing enclosure performance, organizations like National Electrical Manufacturers Association (NEMA), Underwriters
Laboratories, Inc. (UL), Canadian Standards Association (CSA), International Electrotechnical Commission (IEC), and Association for Electrical,
Electronic and Information Technologies (Verband der Elektrotechnik, Elektronik und Informationstechnik [VDE]) use rating systems to
identify the ability of an enclosure to resist external environmental influences. Resistance to everything from dripping liquid, to hosedown, to
total submersion is defined by the rating systems. While all these rating systems are intended to provide information to help you make a
safer, more informed enclosure choice, there are notable differences between the rating systems.
North American Standards Organizations
In North America, NEMA, UL, and CSA are the commonly recognized standards organizations. Their ratings are based on similar application
descriptions and expected performance. UL and CSA both require enclosure testing by qualified evaluators in UL- and CSA-certified labs.
They also send site inspectors to verify that a manufacturer adheres to prescribed manufacturing methods and material specifications.
NEMA does not require independent testing and does not verify the compliance of the manufacturer.
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 9
Chapter 1 Environmental Considerations
North American enclosure rating systems also include a 4X rating that indicates corrosion resistance. This rating is based on the ability of
the enclosure to withstand prolonged exposure to saltwater spray. While a 4X rating is a good indicator that an enclosure can resist
corrosion, it does not provide information on how a specific corrosive agent will affect a given enclosure material. It is best to conduct a full
analysis of the specific application and environment to determine the best enclosure choice.
International Standards Organizations
Like NEMA, IEC does not require independent testing and does not verify the compliance of the manufacturer. Nevertheless, there are
differences in how enclosure performance is interpreted. For example, UL and CSA test requirements specify that an enclosure fails the
water-tight test if even a single drop of water enters the enclosure. In the IEC standards for each level of ingress protection (IP), a certain
amount of water is allowed to enter the enclosure.
IEC 60529 IP ratings do not specify construction requirements or degrees of protection against corrosive atmospheres, risk of explosion, or
conditions such as moisture or corrosive vapors. NEMA Type ratings do specify construction and performance requirements for most
environmental conditions. Because of this difference in construction requirements, and because the tests and evaluations for other
characteristics are not identical, the IEC enclosure classification designations cannot be exactly equated with NEMA enclosure Type
numbers.
Enclosure materials and construction must consider the following:
• Environmental considerations include moisture, temperature, solar affect, airborne particulate matter, and harsh or corrosive
chemicals present in the atmosphere.
• Safety issues including electrical code requirements, grounding needs, and others.
Choosing the incorrect solution can be costly and can adversely affect the performance of your installation.
Degree of Protection
IEC Publication 60529 describes standard Degrees of Protection that enclosures are designed to provide when properly installed.
Summary
The publication defines Degrees of Protection with respect to:
•Persons
• Equipment within the enclosure
• Ingress of water
It does not define:
• Protection against risk of explosion
• Environmental protection (for example: against humidity, corrosive atmospheres or fluids, fungus, or the ingress of vermin)
Note: The IEC test requirements for Degrees of Protection against liquid ingress refer only to water. The products on the Safety Products
page (https://ab.rockwellautomation.com/Safety
Nitrile seals. Nitrile seals have good resistance to a wide range of oils, coolants, and cutting fluids; however, some of the available lubricants,
hydraulic fluids, and solvents can cause severe deterioration of Nitrile and other polymers. Some of the products listed are available with
seals of Viton or other materials for improved resistance to such liquids. For specific advice on enclosure seals and protection against liquid
ingress, contact your local Rockwell Automation sales office.
) that have a high degree of protection against ingress of liquid include, in most cases,
10 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Chapter 1 Environmental Considerations
IEC Enclosure Classification
The IEC enclosure classification for degree of protection is indicated by two letters and two numerals (IP_ _). International Standard IEC
60529 contains descriptions and associated test requirements that define the degree of protection that each numeral specifies. Table 1
indicates the general degree of protection indicated by the value and position of each numeral in the enclosure classification.
See the Abridged Descriptions of IEC Enclosure Test Requirements below for brief descriptions of the test requirements.
Note: For complete test requirements refer to IEC 60529.
Abridged Descriptions of IEC Enclosure Test Requirements
Refer to IEC 60529 for complete test specifications (for example: test apparatus configuration, tolerances, etc). For metric conversion
factors, see Safety Products page (https://ab.rockwellautomation.com/Safety
Tests for Protection Against Access to Hazardous Parts (first characteristic numeral)
).
The first characteristic numeral of the IP number indicates compliance with the following tests for the degree of protection against access
to hazardous parts. It also indicates compliance with tests shown in Tests for Protection Against Solid Foreign Objects (first characteristic
numeral) on page 12.
The protection against access to hazardous parts is satisfactory if adequate clearance is kept between the specified access probe and
hazardous parts. For voltage less than 1000V AC and 1500V DC, the access probe must not touch the hazardous live parts. For voltage
exceeding 1000V AC and 1500V DC, the equipment must be capable of withstanding specified dielectric tests with the access probe in the
most unfavorable position.
Table 1 - Numeric Conventions for Protection Against Access to Hazardous Parts
First Numeral
Protection of persons against access to hazardous
parts and protection against penetration of solid
foreign objects.
0 – Non-protected 0 – Non-protected
1 – Back of hand; objects greater than 50 mm in diameter 2 – Vertically falling drops of water
3 – Finger; objects greater than 12.5 mm in diameter 4 – Vertically falling drops of water with enclosure tilted 15°
5 – Tools or objects greater than 2.5 mm in diameter 6 – Spraying water
7 – Tools or objects greater than1.0 mm in diameter 8 – Splashing water
9 – Dust-protected (dust can enter during specified test
but must not interfere with operation of the equipment or
impair safety)
11 – Dusttight (no dust observable inside enclosure at
end of test)
Example: IP41 describes an enclosure that is designed to protect against the entry of tools or objects greater than 1 mm
in diameter and to protect against vertically dripping water under specified test conditions.
Note: All first numerals and second numerals up to and including characteristic numeral 6, imply compliance also with
the requirements for all lower characteristic numerals in their respective series (first or second). Second numerals 7 and
8 do not imply suitability for exposure to water jets (second characteristic numeral 5 or 6) unless dual coded; e.g., IP_5/
IP_7.
(1) The IEC standard permits use of certain supplementary letters with the characteristic numerals. If such letters are
used, refer to IEC 60529 for the explanation.
(1)
Second Numeral
Protection against ingress of water under test conditions
specified in IEC 60529.
10 – Water jets
12 – Powerful water jets
13 – Temporary submersion
14 – Continuous submersion
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 11
Chapter 1 Environmental Considerations
IP0_ No test required.
IP1_
A rigid sphere 50 mm in diameter shall not completely pass through any
opening. Force = 50 N.
A jointed test finger 80 mm long and 12 mm in diameter can penetrate to its
IP2_
80 mm length, but shall have adequate clearance as specified above, from
hazardous live parts, in every possible position of the test finger as both
joints are bent through an angle up to 90°. Force = 10 N.
A test rod 2.5 mm in diameter shall not penetrate and adequate clearance
IP3_
shall be kept from hazardous live parts
(as specified in Table 1
). Force = 3 N.
A test wire 1 mm in diameter shall not penetrate and adequate clearance
IP4_
shall be kept from hazardous live parts
(as specified in Table 1
). Force = 1 N.
A test wire 1 mm in diameter shall not penetrate and adequate clearance
IP5_
shall be kept from hazardous live parts
(as specified in Table 1
). Force = 1 N.
A test wire 1 mm in diameter shall not penetrate and adequate clearance
IP6_
shall be kept from hazardous live parts
(as specified in the Table 1
). Force = 1 N.
Tests for Protection Against Solid Foreign Objects (first characteristic numeral)
For first numerals 1, 2, 3, and 4, the protection against solid foreign objects is satisfactory if the full diameter of the specified probe does not
pass through any opening. Note that for first numerals 3 and 4, the probes are intended to simulate foreign objects which can be spherical.
Where shape of the entry path leaves any doubt about ingress or a spherical object capable of motion, it can be necessary to examine
drawings or to provide special access for the object probe. For first numerals 5 and 6, see test descriptions below for acceptance criteria.
IP0_ No test required.
IP1_
IP2_
IP3_
The full diameter of a rigid sphere 50 mm in diameter must not pass through
any opening at a test force of 50 N.
The full diameter of a rigid sphere 12.5 mm in diameter must not pass
through any opening at a test force of 30 N.
A rigid steel rod 2.5 mm in diameter must not pass through any opening at a
test force of 3 N.
12 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Chapter 1 Environmental Considerations
IP4_
IP5_
IP6_
A rigid steel wire 1 mm in diameter must not pass through any opening at a
test force of 1 N.
The test specimen is supported inside a specified dust chamber where
talcum powder, able to pass through a square-mesh sieve with wire
diameter 50 mm and width between wires 75 mm, is kept in suspension.
Enclosures for equipment subject to thermal cycling effects (category 1) are
vacuum pumped to a reduced internal pressure relative to the surrounding
atmosphere: maximum depression = 2 kPa; maximum extraction rate = 60
volumes per hour. If extraction rate of 40 to 60 volumes/hr is obtained, test
is continued until 80 volumes have been drawn through or 8 hours has
elapsed. If extraction rate is less than 40 volumes/hr at 20 kPa depression,
test time = 8 hr.
Enclosures for equipment not subject to thermal cycling effects, and
designated category 2 in the relevant product standard, are tested for 8
hours without vacuum pumping.
Protection is satisfactory if talcum powder has not accumulated in a
quantity or location such that, as with any other kind of dust, it could
interfere with the correct operation of the equipment or impair safety, and
no dust has been deposited where it could lead to tracking along creepage
distances.
All enclosures are tested as category 1, as specified above for IP5_. The
protection is satisfactory if no deposit of dust is observable inside the
enclosure at the end of the test.
Tests for Protection Against Water (second characteristic numeral)
The second characteristic numeral of the IP number indicates compliance with the following tests for the degree of protection against
water. For numerals 1 through 7, the protection is satisfactory if any water that has entered does not interfere with satisfactory operation,
does not reach live parts not designed to operate when wet, and does not accumulate near a cable entry or enter the cable. For second
numeral 8, the protection is satisfactory if no water has entered the enclosure.
IP_0 No test required.
Water is dripped onto the enclosure from a “drip box” having spouts spaced
IP_1
IP_2
IP_3
IP_4 Same as test for IP_3 except spray covers an arc of 180° from vertical.
on a 20 mm square pattern, at a “rainfall” rate of 1 mm/min The enclosure is
placed in its normal operating position under the drip box. Test time = 10 min
Water is dripped onto the enclosure from a “drip box” having spouts spaced
on a 20 mm square pattern, at a “rainfall” rate of 3 mm/min The enclosure is
placed in 4 fixed positions tilted 15° from its normal operating position,
under the drip box. Test time = 2.5 min for each position of tilt.
Water is sprayed onto all sides of the enclosure over an arc of 60° from
vertical, using an oscillating tube device with spray holes 50 mm apart (or a
hand-held nozzle for larger enclosures). Flow rate, oscillating tube device =
0.07 l/min per hole x number of holes; for hand-held nozzle = 10 l/min Test
time, oscillating tube = 10 min; for hand-held nozzle = 1 min/m2 of enclosure
surface area, 5 min minimum.
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 13
Chapter 1 Environmental Considerations
Enclosure is sprayed from all practicable directions with a stream of water
IP_5
IP_6
IP_7
IP_8
at 12.5 l/min from a 6.3 mm nozzle from a distance of 2.5 to 3 m. Test time =
1 min/m2 of enclosure surface area to be sprayed, 3 min minimum.
Enclosure is sprayed from all practicable directions with a stream of water
at 100 l/min from a 12.5 mm nozzle from a distance of 2.5 to 3 m. Test time =
1 min/m2 of enclosure surface area to be sprayed, 3 min minimum.
Enclosure is immersed in water in its service position for 30 min Lowest
point of enclosures less than 850 mm tall = 1000 mm below surface of water.
Highest point of enclosures more than 850 mm tall = 150 mm below surface
of water.
Test conditions are subject to agreement between manufacturer and user,
but shall be at least as severe as those for IP_7.
Abridged Descriptions of NEMA Enclosure Test Requirements
NEMA is a commonly recognized standards organization in North America and publishes standards for enclosures. It does not require
independent verification of these tests.
6.2 Rod Entry Test
A 3.18 mm (0.125 in.) diameter rod must not be able to enter enclosure except at locations where nearest live part is more than 102 mm (4 in.)
from an opening — such opening shall not permit a 13 mm (0.5 in.) diameter rod to enter.
6.3 Drip Test
Water is dripped onto enclosure for 30 minutes from an overhead pan having uniformly spaced spouts, one every 12,900 mm (20 in.) of pan
area, each spout having a drip rate of 20 drops per minute.
Evaluation 6.3.2.2: No water shall have entered enclosure.
6.4 Rain Test
Entire top and all exposed sides are sprayed with water at a pressure of
0.35 kg/cm2 (5 psi) from nozzles for one hour at a rate to cause water to rise 457 mm (18 in.) in a straight-sided pan beneath the enclosure.
Evaluation 6.4.2.1: No water shall have reached live parts, insulation, or mechanisms.
Evaluation 6.4.2.2: No water shall have entered enclosure.
6.5.1.1 (2) Outdoor Dust Test (Alternate Method)
Enclosure and external mechanisms are subjected to a stream of water at 170.5 liters (45 gallons) per minute from a 25.4 mm (1 in.) diameter
nozzle, directed at all joints from all angles from a distance of 3…3.7 m (10…12 ft). Test time is 48 seconds times the test length (height +
width + depth of enclosure in feet), or a minimum of 5 minutes. No water shall enter enclosure.
14 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Chapter 1 Environmental Considerations
6.5.1.2 (2) Indoor Dust Test (Alternate Method)
Atomized water at a pressure of 2.11 kg/cm2 (30 psi) is sprayed on all seams, joints and external operating mechanisms from a distance of
305…381 mm (12…15 in.) at a rate of 11 liters (3 gallons) per hour. No less than 142 gms
(5 oz) of water per linear foot of test length (height + length + depth of enclosure) is applied. No water shall enter enclosure.
6.6 External Icing Test
Water is sprayed on enclosure for one hour in a cold room 2 °C (36 °F); then room temperature is lowered to approximately –5 °C (–23 °F) and
water spray is controlled so as to cause ice to build up at a rate of 6.4 mm (0.25 in.) per hour until 19 mm (0.75 in.) thick ice has formed on top
surface of a 25.4 mm (1 in.) diameter metal test bar, then temperature is maintained at –5 °C (–23 °F) for 3 hours.
Evaluation 6.6.2.2: Equipment shall be undamaged after ice has melted (external mechanisms not required to be operable while iceladen).
6.7 Hosedown Test
Enclosure and external mechanisms are subjected to a stream of water at 246 liters (65 gallons) per minute from a 25.4 mm (1 in.) diameter
nozzle, directed at all joints from all angles from a distance of 3…3.7 m (10...12 ft). Test time is 48 seconds times the test length [height +
width + depth] of enclosure in meters (feet), or a minimum of 5 seconds. No water shall enter enclosure.
6.8 Rust Resistance Test (Applicable Only to Enclosures Incorporating External Ferrous Parts)
Enclosure is subjected to a salt spray (fog) for 24 hours, using water with five parts by weight of salt (NaCI), at 35 °C (95 °F), then rinsed and
dried. There shall be no rust except where protection is impractical (for example, machined mating surfaces, sliding surfaces of hinges,
shafts, etc.).
6.9 Corrosion Protection
Sheet steel enclosures are evaluated per Underwriter's Laboratories (UL) 50, Part 13 (test for equivalent protection as G-90 commercial zinc
coated sheet steel). Other materials per Underwriter's Laboratories (UL) 508, 6.9 or 6.10.
6.11 (2) Air Pressure Test (Alternate Method)
Enclosure is submerged in water at a pressure equal to water depth of 2 m (6 ft), for 24 hours. No water shall enter enclosure.
6.12 Oil Exclusion Test
Enclosure is subjected to a stream of test liquid for 30 minutes from a 9.5 mm (0.375 in.) diameter nozzle at 7.57 liters (2 gallons) a minute.
Water with 0.1% wetting agent is directed from all angles from a distance of 305…457 mm (12…18 in.), while any externally operated device is
operated at 30 operations per minute. No test liquid shall enter the enclosure.
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 15
Chapter 1 Environmental Considerations
Abridged Descriptions of UL Standard 698 Test Requirements
The following descriptions are based on the descriptions in the UL Standard 698 Test Requirements.
Explosion Test
During a series of tests in which gas-air mixtures of the specific gas, over its range of explosive concentrations, are ignited inside the
enclosure, the enclosure shall prevent the passage of flame and sparks capable of igniting a similar gas-air mixture surrounding the
enclosure. In addition, there shall be no mechanical damage to enclosed electrical mechanisms or the enclosure.
Hydrostatic Test
The enclosure shall withstand for one minute a hydrostatic test based on the maximum internal explosion pressure developed during the
explosion tests, as follows: cast metal, four times the explosion pressure without rupture or permanent deformation; fabricated steel, twice
the explosion pressure without permanent deformation and three times the explosion pressure without rupture. Exception: Hydrostatic tests
can be omitted if calculations show safety factor of 5:1 for cast metal, and 4:1 for fabricated steel.
Temperature Test
The enclosed device is subjected to a temperature test to determine maximum temperature at any point on the external surface. The device
must be marked with a temperature code based on the result only if the temperature exceeds 100 °C (212 °F).
Dust Penetration Test
The device is operated at full rated load until equilibrium temperatures are attained, then allowed to cool to ambient (room) temperature,
through six heating and cooling cycles covering at least 30 hours, while continuously exposed to circulating dust of specified properties in a
test chamber. No dust shall enter the enclosure.
Temperature Test with Dust Blanket
This test is conducted as described for the Dust Penetration test except that the re-circulating dust nozzles are positioned so that the dust
is not blown directly on the device under test. The device is operated at full rated load (and under abnormal conditions for equipment subject
to overloading) until equilibrium temperatures are attained. Dust in contact with the enclosure shall not ignite or discolor from heat, and the
exterior surface temperatures based on 40 °C (104 °F) ambient shall not exceed the values listed below.
Class II, Group Normal Operating Conditions Abnormal Operating Conditions
E 200 °C (392 °F) 200 °C (392 °F)
F 150 °C (302 °F) 200 °C (392 °F)
G 120 °C (248 °F) 165 °C (329 °F)
Enclosure Type Descriptions
This section provides enclosure type descriptions for hazardous and non-hazardous locations.
16 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Chapter 1 Environmental Considerations
Type 1 – General Purpose Surface Mounting
Type 1 enclosures are intended for indoor use primarily to provide a degree of protection against contact with the enclosed
equipment in locations where unusual service conditions do not exist. The enclosures are designed to meet the rod-entry and
rust-resistance design tests. Enclosure is sheet steel, treated to resist corrosion.
Type 1 – Flush Mounting
Type 1 Flush Mounting enclosures for installation in machine frames and plaster wall. These enclosures are for similar applications and are
designed to meet the same tests as Type 1 surface mounting.
Type 3 – Rainproof Dusttight
Type 3 enclosures are intended for outdoor use primarily to provide a degree of protection against windblown dust, rain, and sleet; and to
be undamaged by the formation of ice on the enclosure. They are designed to meet rain
(1)
, external icing
tests. They are not intended to provide protection against conditions such as internal condensation or internal icing.
(2)
, dust, and rust-resistance design
Type 3R – Rainproof
Type 3R enclosures are intended for outdoor use primarily to provide a degree of protection against falling rain, and to be undamaged by
the formation of ice on the enclosure. They are designed to meet rod entry, rain
(3)
external icing
(4)
, and rust resistance design tests. They are
not intended to provide protection against conditions such as dust, internal condensation, or internal icing.
Type 4 – Watertight
Type 4 enclosures are intended for indoor or outdoor use primarily to provide a degree of protection against windblown dust
and rain, splashing water, and hose-directed water; and to be undamaged by the formation of ice on the enclosure. They are
(4)
designed to meet hosedown, dust, and external icing tests
. They are not intended to provide protection against conditions
such as internal condensation or internal icing.
Type 4X – Non-metallic, Corrosion-resistant
Type 4X enclosures are intended for indoor or outdoor use primarily to provide a degree of protection against corrosion,
windblown dust and rain, splashing water, and hose-directed water; and to be undamaged by the formation of ice on the
(4)
enclosure. They are designed to meet the hosedown, dust, external icing
not intended to provide protection against conditions such as internal condensation or internal icing.
, and corrosion-resistance design tests. They are
(1) Evaluation criteria: No water has entered enclosure during specified test.
(2) Evaluation criteria: Undamaged after ice buildup during specified test has melted. (Note: Not required to be operable while iceladen.)
(3) Evaluation criteria: No water shall have reached live parts, insulation or mechanisms.
(4) Evaluation criteria: Undamaged after ice buildup during specified test has melted. (Note: Not required to be operable while iceladen.)
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 17
Chapter 1 Environmental Considerations
Type 6P – For Prolonged Submersion at a Limited Depth
Type 6P enclosures are intended for indoor or outdoor use primarily to provide a degree of protection against the entry of water during
prolonged submersion at a limited depth; and to be undamaged by the formation of ice on the enclosure. They are designed to meet air
(1)
pressure, external icing
such as internal condensation or internal icing.
, hosedown and corrosion-resistance design tests. They are not intended to provide protection against conditions
Type 7 – For Hazardous Gas Locations
Type 7 enclosures are for indoor use in locations classified as Class I, Groups C or D, as defined in the U.S. National Electrical
Code. Type 7 enclosures are designed to be capable of withstanding the pressures resulting from an internal explosion of
specified gases, and contain such an explosion sufficiently that an explosive gas-air mixture existing in the atmosphere
surrounding the enclosure will not be ignited. Enclosed heat generating devices are designed not to cause external surfaces
to reach temperatures capable of igniting explosive gas-air mixtures in the surrounding atmosphere. Enclosures are
designed to meet explosion, hydrostatic, and temperature design tests. Finish is a special corrosion-resistant, gray enamel.
Type 9 – For Hazardous Dust Locations
Type 9 enclosures are intended for indoor use in locations classified as Class II, Groups E, F, or G, as defined in the U.S.
National Electrical Code. Type 9 enclosures are designed to be capable of preventing the entrance of dust. Enclosed heat
generating devices are designed not to cause external surfaces to reach temperatures capable of igniting or discoloring dust
on the enclosure or igniting dust-air mixtures in the surrounding atmosphere. Enclosures are designed to meet dust
penetration and temperature design tests, and aging of gaskets. The outside finish is a special corrosion-resistant gray
enamel.
Type 12 – Dusttight Industrial Use
Type 12 enclosures are intended for indoor use primarily to provide a degree of protection against dust, falling dirt, and
dripping non-corrosive liquids. They are designed to meet
(2)
drip
, dust, and rust-resistance tests. They are not intended to provide protection against conditions such as internal
condensation.
Type 13 – Oiltight
Type 13 enclosures are intended for indoor use primarily to provide a degree of protection against dust, spraying of water,
oil, and noncorrosive coolant. They are designed to meet oil exclusion and rust-resistance design tests. They are not intended
to provide protection against conditions such as internal condensation.
(1) Evaluation criteria: No water has entered enclosure during specified test.
(2) Evaluation criteria: Undamaged after ice buildup during specified test has melted. (Note: Not required to be operable while iceladen.)
18 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Chapter 1 Environmental Considerations
Enclosure Type Descriptions for Non-hazardous Locations
This section compares the enclosure type descriptions for non-hazardous locations between NEMA, UL, and CSA standards.
Location Enclosure Type
NEMA
(1)
Indoor Type 1 Enclosures are intended for indoor use
primarily to provide a degree of protection
against contact with the enclosed equipment
(2) (3)
UL
Indoor use primarily to provide protection
against contact with the enclosed equipment
and against a limited amount of falling dirt.
(4)
CSA
General purpose enclosure. Protects against
accidental contact with live par ts.
or locations where unusual service conditions
do not exist.
Indoor Type 12 Enclosures are intended for indoor use
primarily to provide a degree of protection
against dust, falling dirt and dripping
noncorrosive liquids.
Indoor use to provide a degree of protection
against dust, dirt, fiber flyings, dripping water
and external condensation of noncorrosive
liquids.
Indoor use; provides a degree of protection
against circulating dust, lint, fibers and
flyings; dripping and light splashing of noncorrosive liquids; not provided with
knockouts.
Indoor Type 12K Enclosures with knockouts are intended for
indoor use primarily to provide a degree of
protection against dust, falling dirt and
dripping noncorrosive liquids.
Indoor use to provide a degree of protection
against dust, dirt, fiber flyings, dripping water
and external condensation of noncorrosive
liquids.
Indoor use; provides a degree of protection
against circulating dust, lint, fibers and
flyings; dripping and light splashing of
noncorrosive liquids; not provided with
knockouts.
Indoor Type 13 Enclosures are intended for indoor use
primarily to provide a degree of protection
against dust, spraying of water, oil and
noncorrosive coolant.
Outdoor Type 3 Enclosures are intended for outdoor use
primarily to provide a degree of protection
against windblown dust, rain and sleet;
undamaged by the formation of ice on the
Indoor use to provide a degree of protection
against lint, dust seepage, external
condensation and spraying of water, oil and
noncorrosive liquids.
Outdoor use to provide a degree of protection
against windblown dust and windblown rain;
undamaged by the formation of ice on the
enclosure.
Indoor use; provides a degree of protection
against circulating dust, lint, fibers and
flyings; seepage and spraying of noncorrosive liquids, including oils and coolants.
Indoor or outdoor use; provides a degree of
protection against rain, snow and windblown
dust; undamaged by the external formation
of ice on the enclosure.
enclosure.
Outdoor Type 3R Enclosures are intended for outdoor use
primarily to provide a degree of protection
against falling rain and sleet; undamaged by
the formation of ice on the enclosure.
Outdoor Type 3RX Enclosures are intended for outdoor use
Outdoor use to provide a degree of protection
against falling rain; undamaged by the
formation of ice on the enclosure.
Indoor or outdoor use; provides a degree of
protection against rain and snow; undamaged
by the external formation of ice on the
enclosure.
Not specifically defined. Not specifically defined.
primarily to provide a degree of protection
against corrosion, falling rain and sleet;
undamaged by the formation of ice on the
enclosure.
Outdoor Type 4 Enclosures are intended for indoor or outdoor
use primarily to provide a degree of protection
against windblown dust and rain, splashing
water and hose-directed water; undamaged
by the formation of ice on the enclosure.
Outdoor Type 4X Enclosures are intended for indoor or outdoor
use primarily to provide a degree of protection
against corrosion, windblown dust and rain,
splashing water and hose-directed water;
undamaged by the formation of ice on the
Either indoor or outdoor use to provide a
degree of protection against falling rain,
splashing water and hose-directed water;
undamaged by the formation of ice on the
enclosure.
Either indoor or outdoor use to provide a
degree of protection against falling rain,
splashing water and hose-directed water;
undamaged by the formation of ice on the
enclosure; resists corrosion.
Indoor or outdoor use; provides a degree of
protection against rain, snow, windblown
dust, splashing and hose-directed water;
undamaged by the external formation of ice
on the enclosure.
Indoor or outdoor use; provides a degree of
protection against rain, snow, windblown
dust, splashing and hose-directed water;
undamaged by the external formation of ice
on the enclosure; resists corrosion.
enclosure.
Outdoor Type 6P Enclosures are intended for use indoors or
outdoors where occasional submersion is
encountered; limited depth; undamaged by
the formation of ice on the enclosure.
(1) Reprinted from NEMA 250-2008, Enclosure Type Non-Hazardous Location, Enclosure Type descriptions, by permission of the National Electrical Manufacturers Association.
(2) © 1995 (UL 50), 2001 (UL 508A), and 2007 (UL 50E) Underwriters Laboratories Inc. Reprinted with permission. This material is not the complete and official position of UL on the
referenced subject, which is represented only by the UL Standard in its entirety.
(3) Underwriters Laboratories Inc. (UL) shall not be responsible for the use of or reliance upon a UL Standard by anyone. UL shall not incur any obligation or liability for damages,
including consequential damages, arising out of or in connection with the use, interpretation of, or reliance upon a UL Standard.
(4) Reproduced with the permission of CSA from CSA C22.2 No. 94.2-07 Enclosures for Electrical Equipment, Environmental Considerations (Tri-National Standard, with NMX-J-235/2-
ANCE-2007 and UL 50E) which is copyrighted by CSA. While use of this material has been authorized, CSA shall not be responsible for the manner in which the information is
presented, nor for any interpretations thereof.
Indoor or outdoor use to provide a degree of
protection against entry of water during
temporary submersion at a limited depth;
undamaged by the external formation of ice
on the enclosure.
Indoor or outdoor use; provides a degree of
protection against the entry of water during
temporary submersion at a limited depth.
Undamaged by the external formation of ice
on the enclosure; resists corrosion.
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 19
Chapter 1 Environmental Considerations
Enclosures Offered by Rockwell Automation
See Selection Criteria for Non-hazardous Locations and Selection Criteria for Hazardous Locations (division 1 or 2) for the types of
enclosures offered by Rockwell Automation. For definitions, descriptions, and test criteria, see National Electrical Manufactures Association
(NEMA) Standards Publication No. 250. Also see individual product listings within the Safety Products page,
(https://ab.rockwellautomation.com/Safety
Note: Enclosures do not normally protect devices against conditions such as condensation, icing, corrosion, or contamination that can occur
within the enclosure or enter via the conduit or unsealed openings. You must make adequate provisions to safeguard against such
conditions and be sure that the equipment is properly protected.
Selection Criteria for Non-hazardous Locations
), for available enclosure types and for any additional information relating to these descriptions.
For a Degree of Protection Against:
Incidental contact with enclosed equipment 6.2 xxxxxxxx
Falling dirt 6.2 xxxxxxxx
Rust 6.8 xxxxxxxx
Circulating dust, lint, fibres, and flyings
Windblown dust 6.5.1.1 (2) x x x x
Falling liquids and light splashing 6.3.2.2 x x x x x x
Rain (Test evaluated per 6.4.2.1) 6.4.2.1 x x x x x
Rain (Test evaluated per 6.4.2.2) 6.4.2.2 x x x x
Snow and sleet 6.6.2.2 x x x x x
Hosedown and splashing water 6.7 x x x
Occasional prolonged submersion 6.11 (2) x
Oil and coolant seepage 6.3.2.2 x x
Oil or coolant spraying and splashing 6.12 x
Corrosive agents 6.9 x x x x x
(1) Non-hazardous materials, not Class III ignitable or combustible.
(2) See Enclosure Type Descriptions for Non-hazardous Locations on page 19. Refer to NEMA Standards Publication No. 250 for complete test specifications.
(2)
Designed to
Meet Test No.
6.5.1.2 (2) x x x x x x
Type
For Indoor Use For Outdoor Use Indoor or Outdoor
(1)
112133R344X6P
Selection Criteria for Hazardous Locations (division 1 or 2)
For a Degree of Protection Against
Atmospheres Typically Containing:
Acetylene Explosion Test
Hydrogen, Manufactured Gas X X
Diethyl Ether, Ethylene, Hydrogen Sulfide X
Acetone, Butane, Gasoline, Propane, Toluene X X
Metal dusts and other combustible dusts with
resistivity of less than 10
Carbon black, charcoal, coal or coke dusts with
resistivity between 10
Combustible dusts with resistivity of 105 -cm or
greater
Fibers, flyings
(1) For indoor locations only, unless cataloged with additional NEMA Type enclosure number(s) suitable for outdoor use as shown in the table on this page. Some control devices (if so
listed in the catalog) are suitable for Division 2 hazardous location use in enclosures for nonhazardous locations. For explanation of CLASSES, DIVISIONS and GROUPS, refer to the
National Electrical Code.
(2) For listing of additional materials and information noting the properties of liquids, gases and solids, refer to NFPA 497M-1991, Classification of Gases, Vapors, and Dusts for
Electrical Equipment in Hazardous (Classified) Locations.
(3) See Enclosure Type Descriptions for Non-hazardous Locations on page 19. For complete requirements, refer to UL Standard 698, compliance with which is required by NEMA
enclosure standards.
(4) UL 698 does not include test requirements for Class III. Products that meet Class II, Group G requirements are acceptable for Class III.
-cm
…10 -cm
(1)(2)
Designed to Meet
(3)
Tes ts
Hydrostatic Test
Temperature Test
Dust Penetration Test
Tem pe ra tu re Test wi th D us t
Blanket
(4)
Class (National
Electrical Code)
IX
II X
III X
7, Class I Group 9, Class II Group
ABCDEFG
X
X
20 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Chapter 2
Industry Related Installation Considerations
This section describes different installation considerations for specific industries. It is not meant to be a comprehensive list and you must
take into account conditions at your specific location.
General Precautions
ATTENTION: Only qualified personnel familiar with adjustable
frequency AC drives and associated machinery should plan or
implement the installation, start-up and subsequent maintenance of
the system. Failure to comply can result in personal injury and/or
equipment damage.
ATTENTION: An incorrectly applied or installed drive can result in
component damage or a reduction in product life. Wiring or
application errors such as under sizing the motor, incorrect or
inadequate AC supply, or excessive surrounding air temperatures can
result in malfunction of the system.
ATTENTION: Severe injury or death can result from electrical shock,
burn, or unintended actuation of controlled equipment. Hazardous
voltages can exist in the drive enclosure even with the circuit breaker
in the off position. Recommended practice is to disconnect and lock
out control equipment from power sources. If it is necessary to work
in the vicinity of energized equipment, the safety related work
practices of NFPA 70E, Electrical Safety Requirements for Employee
Workplaces, must be followed. DO NOT work alone on energized
equipment.
ATTENTION: To avoid an electric shock hazard, verify that the
voltage on the bus capacitors has discharged before performing any
work on the drive. Measure the DC bus voltage at the +DC and -DC
terminals of the Power Terminal Block. The voltage must be zero.
General Information
As with any AC drive installation there are many items that must be considered. In general, the selection of an enclosure for an AC drive is
based on the type of environment in which the AC drive will be applied. Specific industries have known contaminants which can contain
particulate matter (solids) and/or harsh chemical gases, and potentially higher ambient temperatures that can require filtering, additional
air flow, or complete sealing of an enclosure to protect the AC drive from the contaminant source.
Contaminants and Conditions by Industry
There are known contaminants in the atmosphere based on the type of application, location of the facility, or location (placement) of the AC
drive (for example: indoor vs. outdoor). This section lists some typical contaminants present in various industries.
Also see Environmental and Atmospheric Considerations by Location
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 21
on page 23) and Table 5 on page 28.
Chapter 2 Industry Related Installation Considerations
Automotive Industry
In the Automotive industry the AC drive is typically an indoor installation. The airborne contaminants that can be present are:
• Hydrogen fluoride
• Oxides of nitrogen
• Hydrocarbons
•Sulfur dioxide
Chemical/Specialty Chemical
In the Chemical/Specialty Chemical industries, the AC drive can be found in both indoor and outdoor installations. The airborne contaminants
that can be present are:
• Organic dust (elemental chemicals such as sulfur)
• Oil-based distillates, which can create an oily film, further attracting other contaminants.
• High humidity levels in outdoor installations
• Caustic cleaners and / or concentrates (for example, ammonia, sodium chloride)
• High-pressure wash down
• NEMA4/4X environment
• Alcohol (Class1, Div 1, environment)
• Hose-directed water which can contain cleaning and other chemicals
Food and Beverage
In the Food and Beverage industry the AC drive is typically an indoor installation. The airborne contaminants that can be present are:
• Organic dust (grains, sugars, etc.)
• Caustic cleaners and/or concentrates (ammonia, sodium chloride, syrups)
• High-pressure wash down
• NEMA4/4X environment
• Alcohol (Class 1, Div 1, environment)
• High temperature/industrial cooking and baking 35 °C (95 °F)
Forest Products Industry/Converting
In the Forest Products/Converting industries, the AC drive is typically an indoor installation. The airborne contaminants that can be present
are:
• Hydrogen sulfide
• Active organic nitrogen
• Carbon monoxide
•Chlorine
• Chlorine dioxide
• Hydrocarbons
•Phosphates
• High moisture or humidity
Mining and Steel
In the Mining and Steel industry the AC drive is typically an indoor installation. The airborne contaminants that can be present are:
• Hydrogen sulfide,
• Hydrogen fluoride,
22 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Chapter 2 Industry Related Installation Considerations
•Carbon,
• Carbon monoxide,
• Inorganic dust,
• Pickle line acid,
• Hydrochloric acid,
• Moisture or humidity
Tire Manufacturing
In the Tire Manufacturing industry the AC drive is typically an indoor installation. The airborne contaminants that can be present are:
• Hydrogen sulfide
•Mercaptans
•Carbon black
Water/Waste Water
In the Water/Waste Water industry the AC drive can be installed either indoors or outdoors. With an indoor installation the airborne
contaminants that can be present are:
• Hydrogen sulfide
• Active organic nitrogen
• Carbon monoxide
•Chlorine
• Chlorine dioxide
• Hydrocarbons
• Moisture or humidity
Marine and Offshore
In the Marine and Offshore industry the AC drive can be installed either indoor (controlled), indoor (uncontrolled or ventilated), or outdoor
(above deck). With an outdoor and indoor (uncontrolled) installation, the environmental conditions that can be present are:
• Salt air
•Fuel oil
• Cleaning solvents
• Corrosive or acidic rain
• High-pressure wash down from hose-directed water or sea water
• Biological elements when in direct contact with sea water
Environmental and Atmospheric Considerations by Location
Location of the AC Drive Environmental and Atmospheric Considerations
Indoor
(Environmentally Controlled)
Indoor
(Uncontrolled Environment)
Outdoor
The International Society of Automation (ISA) standard Environmental Conditions for Process Measurement and Control Systems: Airborne
Contaminants (ISA-71.04-2013) describes many of the types of contamination and categorizes the severity of environments. The ISA defines
four severity levels as described in Explanation of Contaminant Severity Levels, below.
Clean air control room, temperature regulated, moisture content, size of the smallest airborne contaminant, corrosive or combustible
gasses, wash-down areas.
Non-conditioned plant floor areas, shipboard machinery rooms, or other fan-ventilated areas. Not typical temperature regulated,
uncontrolled moisture content, airborne contaminant limited by ventilation system and filters, wash-down areas.
Maximum and minimum ambient temperatures, wind, rain, snow, dust, direct sunlight (solar heating), close proximity to the ocean or salt
air, seismic activity.
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 23
Chapter 2 Industry Related Installation Considerations
Explanation of Contaminant Severity Levels
This section describes contaminant severity levels to standardize descriptions across different industries.
Explanation of Contaminant Severity Levels
There is a broad distribution of contaminant concentrations and reactivity levels existing within industries using process measurement and
control equipment. Some environments are severely corrosive, while others are mild.
The purpose of the contaminant classes is to define environments on the basis of corrosion rate of specially prepared and tested copper and
silver samples, which is prepared and tested as described in Appendix C of ISA-71.04-2013.
Severity Level G1
Mild – An environment sufficiently well-controlled such that corrosion is not a factor in determining equipment reliability.
Severity Level G2
Moderate – An environment in which the effects of corrosion are measurable and can be a factor in determining equipment reliability.
Severity Level G3
Harsh – An environment in which there is a high probability that corrosive attack will occur. These harsh levels should prompt further
evaluation resulting in environmental controls or specially designed and packaged equipment.
Severity Level GX
Severe – An environment in which only specially designed and packaged equipment would be expected to survive. Specifications for
equipment in this class are a matter of negotiation between user and supplier.
Table 2 - Classification of Reactive Environments (ISA Table 3)
Severity Level G1 Mild G2 Moderate G3 Harsh Gx Severe
Copper reactivity level (in
angstroms)
Silver reactivity level (in angstroms)
(1) Normalized to a 30-day exposure. See Annex C, item numbers C.2, C.3 of ISA-71.04-2013.
(1)
Both copper and silver reactivity levels shall be used for environmental monitoring with the higher of the copper and silver corrosion rates
determining the overall severity level.
For reliable operation of electronic equipment, a G1 level should be maintained around the electronics. The following chart from the ISA
standard further describes the severity levels.
<300 <1000 <2000 2000
(1)
<200 <1000 <2000 2000
The gas concentration levels shown in Table 3
Levels stated in Table 2
24 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
, providing the relative humidity is less than 50%. For a given gas concentration, the Severity Level (and Copper
are provided for reference purposes. They are believed to approximate the Copper Reactivity
Chapter 2 Industry Related Installation Considerations
Reactivity Level) can be expected to be increased by one level for each 10% increase in relative humidity above 50% or for a humidity rate
of change greater than 6% per hour.
Table 3 - Contaminant Concentrations Versus Severity Levels (ISA Table B1)
Severity Level
Contaminant Gas
H2S
SO
, SO
2
Group A
Reactive Species
(1)(2)
(3)
Group B
(1) Parts per billion by volume (ppbv) average for test period for the gases in Groups A and B.
(2) The Group A contaminants often occur together and the reactivity levels include the synergistic effects of these
contaminants.
(3) The synergistic effects of Group B contaminants are not known at this time.
3
CI
2
NO
x
HF <1 <2 <10 10
NH
3
0
3
G1
Mild
<3 <10 <50 50
<10 <100 <300 300
<1 <2 <10 10
<50 <125 <1250 1250
<500 <10,000 <25,000 25,000
<2 <25 <100 100
G2
ModerateG3Harsh
Gas Concentration
GX
Severe
(1)
Taken from ANSI/ISA-74.01-2013 - Copyright © 2013 ISA. All rights reserved. Reproduced and distributed with permission of ISA.
Relative Humidity
High relative humidity accelerates the corrosion caused by gaseous contaminants in an exponential manner. Equally important is
recognition of the fact that temperature fluctuations dramatically affect relative humidity and often induce local condensation. Although
water is universally present in industrial atmospheres, the concentration varies widely. It promotes the corrosive degradation of equipment
in three major ways:
1. Directly, as a reactive chemical attacking metals and plastics.
2. Interactively with other atmospheric constituents, in most cases forming a more reactive combination; an example is sulfur dioxide,
, which combines with water to form sulfurous acid.
SO
2
3. Electrochemically: Many species when dissolved in water form a conductive solution. When electric potential differences exist
between two dissimilar metals, the conditions for electrolytic or galvanic corrosion processes are set up. These are different
phenomena, but both are caused by and/or promoted by an electrolyte.
Duty Rating of the AC Drive Application
When designing AC drive enclosure systems for any environment, a consideration of the operating duty rating is useful in determining the
worst-case temperature rise. The internal AC drive enclosure consists of components with continuous heat losses and those which are
generated while power components are conducting. When considering the later, an understanding of the duty rating of the system is useful
in determining the required enclosure cooling system. Always consider the published maximum operating temperature to be the highest
permissible temperature for the air inside an enclosure containing the drive (unless you first consult with the factory). Below are some
definitions of the different types of duty ratings from least to most stringent.
Periodic Duty Rating
The periodic duty rating of a rotating machine is the rated kW load at which the machine can operate repeatedly, for specified period (N) at
the rated load followed by a specified period (R) of rest and de-energized state, without exceeding the given maximum temperature.
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 25
Chapter 2 Industry Related Installation Considerations
Short-time Duty Rating
The short-time duty rating of a rotating electrical machine is the rated kW load at which the machine can operate for a specified time period
without exceeding the given temperature. A rest and de-energized period sufficient to re-establish the machine temperature prior to the
next operation is allowed.
Non-periodic Duty Rating
The non-periodic duty rating of a rotating electrical machine is the kW load at which the machine can operate continuously, for a specific
period of time, or intermittently under the designed variations of the load and speed within the permissible operating range, respectively;
and the given temperature, measured when the machine has been run until it reaches a steady temperature condition.
Continuous Duty Rating
The continuous duty rating of a rotating electrical machine is the rated kW load at which the machine can continuously operate without
exceeding the given steady state temperature.
Protecting Electronic Modules From Contaminants
This section describes different methods of protecting electronic components from contaminants.
Shielding by Enclosures
The most effective control for reducing the rate of corrosion is shielding the electronic modules by appropriate enclosures. If the
environment is not too severe then simple enclosures, such as NEMA Type 12, can be adequate. To provide protection from the process
environment, the enclosure must have a low air-exchange rate. To achieve this there must be no openings of the enclosure walls, and doors
must be maintained closed. A well-sealed enclosure will protect against fibers, dust, splashing, and dripping.
If temperature rise within the enclosure is a concern, heat exchangers or air conditioners can be used. To prevent condensation from
occurring, be sure that air conditioners do not blow cold air directly to the electronic modules. Some temperature rise within the enclosure
actually reduces the rate of corrosion by depressing the relative humidity. This reduction in humidity can be significant even with modest
temperature rises.
If the environment has high humidity, or cyclic high humidity, the electronic equipment can be powered on at all times to keep the inside of
the enclosure dry. If this is not practical, install anti-condensation heaters for when the equipment is not powered on or not running. In
addition to the correct enclosure solution, the printed circuit boards of the AC drive should be conformally coated for added protection
against corrosion to internal sensitive circuits.
Source Control
In some applications the contaminants have a localized source. Isolate the contamination from the electronic equipment using ventilation,
segregation of environments, equipment closets, control rooms, or other barriers and methods.
26 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Chapter 2 Industry Related Installation Considerations
Ventilation Control and Removal Control
If the environment is severe, more aggressive control can be necessary. Ventilation of the control room with a clean source of air can be
required. Typically, a slight positive pressure prevents the room from filling with contaminants. For ventilation alone to be successful, a
clean source of air must be available. Also in severe environments, active removal control can be required. This can involve control rooms
with active air filtration systems. A variety of filter media is available including activated carbon and permanganate impregnated alumina.
Environmental control companies can help design the optimum system to prevent contamination and corrosion.
Outdoor Installations
For outdoor installations, follow the same shielding and control precautions listed above to protect against contaminants; however, the
outdoor environment is now a factor as well. The AC drive carries a specified ambient temperature rating for proper operation which must
be maintained in the outdoor environment. Generally, outdoor installations require a sealed enclosure system with additional cooling. If the
equipment is placed in direct sunlight, you must also consider the effects of additional solar heating. If the equipment is placed in cold or
damp locations, you must also consider internal heaters to maintain at minimum the lowest specified temperatures during periods when the
equipment is not running.
Protecting Electronic Modules During Installation
Because of direct exposure to the process environment during installation, the electronic modules can be exposed to contaminants and are
susceptible to corrosion damage. After this exposure, failures can occur even after the electronic modules are sealed within enclosures. To
minimize the potential for failure, follow these precautions.
• Complete the construction and wiring (as much as possible) of the control rooms before the electronic modules are unpacked.
• Minimize the time the electronic modules remain in an unprotected area.
• Always use protective bags for electronic module storage.
• Keep doors to control rooms and enclosures closed unless opening the door is a necessity.
IMPORTANT Rockwell Automation strongly recommends the use of grounded
neutral systems. See Delta/Wye with Grounded Wye Neutral
page 31.
on
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 27
Chapter 2 Industry Related Installation Considerations
Sources of Reactive Contaminants and Emissions
Additional information on common sources of reactive contaminants and emissions from natural and industrial process can be found in
and Table 5. These include corrosive contaminants that can be liquid, solid, or gaseous in nature.
Table 4
Table 4 - Common Sources of Reactive Environmental Constituents (ISA Table B2)
Category Symbol Constituent Some Common Sources
Gas
Gas
Gas
H
2
, SO
SO
2
S8, R-SH
Hydrogen Sulfide
Sulfur dioxide
3
Mercaptans Foundries, sulfur manufacture
S
Gas HF Hydrogen fluoride
Gas NOx Oxides of nitrogen Automobile emissions, fossil fuel combustion, microbes, chemical industry
Gas
Gas
N
NH
2
3
Active organic nitrogen Automobile emissions, animal waste, vegetable combustion, sewage, wood pulping
Ammonia
Solid C Carbon Incomplete combustion (aerosol constituent), foundry
Gas CO Carbon monoxide Combustion, automobile emissions, microbes, trees, wood pulping
Gas
CI
2
Chlorine, chlorine dioxide
2
, CIO
Gas HCI Hydrogen chloride Automobile emissions, combustion, oceanic processes, polymer combustion
Gas HBr, HI Halogen compounds Automotive emissions
Liquid Cl Chloride ions Aerosol content, oceanic processes, ore processing
Gas
Gas
O
3
C
nHn
Ozone
Hydrocarbons
Solid — Inorganic dust Crystal rock, rock and ore processing, combustion, blowing sand, and many industrial sources
Geothermal emissions, microbiological activities, fossil fuel processing, wood pulping, sewage
treatment, combustion of fossil fuel, auto emissions, ore smelting, sulfuric acid manufacture
Combustion of fossil fuel, auto emissions, ore smelting, sulfuric acid manufacture, tobacco
smoke
Fertilizer manufacture, aluminum manufacture, ceramics manufacture, steel manufacture,
electronics device manufacture, fossil fuel
Microbes, sewage, fertilizer manufacture, geothermal steam, refrigeration equipment,
cleaning products, reproduction (blueprint) machines
Chlorine manufacture, aluminum manufacture, paper mills, refuse decomposition, cleaning
products
Atmospheric photochemical processes mainly involving nitrogen oxides and oxygenated
hydrocarbons, automotive emissions, electrostatic filters
Automotive emissions, fossil fuel processing, tobacco smoke, water treatment, microbes,
paper mill, and many other sources, both natural and industrial
Table 5 - Common Emissions of Natural and Industrial Processes (ISA Table B3)
Natural Processes Emissions
, NH3, NOx, H2S, CO, large variety of organics of many types
Microbes
Sewage
Geothermal
Marshy area
Animal matter Many organics, mainly oxygenated
Forest fire
Oceans NaCl, chloride ions
Industrial Processes Emissions
Power generation
Automotive combustion
Diesel combustion CO, NOx, many organics
Fossil fuel processing
Plastic manufacture
Cement plants
Steel blast furnaces
Steel electric furnaces
Coke plants
Pulp manufacture
Chlorine plants Chlorine, chlorine compounds, NaCl
Fertilizer manufacture
H
2
, aldehydes, many organics, H2S, mercaptans, H2, S, CO
NH
3
, H2S, S02
H
2
H
S, NH3, S02
2
HCI, CO, CO
S0
S0
H
2
All organics, aldehydes, alcohols, NH
S0
H
2
H
2
H
2
Cl
2
HF, NH
2
, C, CO, NOx, hydrocarbons, organics
2
, S03, HCI, HBr, NOx, hydrocarbons, organics, CO, HBr
2
S, S, S02, NH3, hydrocarbons, other organics, mercaptans
, S02
3
, dust, S02, NOx, CO
3
S, S02, CO, HF, coal dust
S, S02, C, CO
S, CO, HCN, carbon, dust
, S02, H2S, CO, wood fibers, dust
, CH4, gas, liquids, dust, acids
3
28 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Chapter 2 Industry Related Installation Considerations
Table 5 - Common Emissions of Natural and Industrial Processes (ISA Table B3) (Continued)
Natural Processes Emissions
Food processing Hydrocarbons, many organics
bber manufacture
Ru
Paint manufacture C, hydrocarbons, oxygenated hydrocarbons, dust
Aluminum manufacture
Ore smelting
Tobacco smoke
Gasoline and fuel vapors Hydrocarbons, oxygenated hydrocarbons
Battery manufacture
H2S, S8, R-SH
HF, S0
, C, dust
2
, CO, H2, dust
S0
2
H
S, S02, HCN, CO, tars and particulates
2
S0
, acids, dust
2
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 29
Chapter 2 Industry Related Installation Considerations
Notes:
30 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Chapter 3
System Configurations, Grounding, Application, and Control
For system configurations, grounding, application, and control, you must consider the specific application of the AC drive, for example:
Pumping, Fan Operation, Conveyor, etc., and the electrical characteristics surrounding that specific application and the different types of
power distribution to which the applications are applied.
Power Distribution
You must evaluate and configure the power distribution systems to provide optimum performance for the AC drive. See
System Configurations and Grounding
For more information, see the Wiring and Grounding Guidelines for Pulse Width Modulated (PWM) AC Drives Installation Instructions,
publication DRIVES-IN001
.
System Configurations and Grounding
, below.
The type of transformer and the connection configuration feeding a drive plays an important role in the performance and safety of the drive.
The following is a brief description of some of the more common configurations and a discussion of their qualities and differences.
Delta/Wye with Grounded Wye Neutral
Delta/Wye with Grounded Wye Neutral is the most common type of distribution system. It provides a 30-degree phase shift. The grounded
neutral provides a direct path for common mode current caused by the drive output (see Chapter 3 and Chapter 6 of Wiring and Grounding
Guidelines for Pulse Width Modulated (PWM) AC Drives Installation Instructions, publication DRIVES-IN001
IMPORTANT Rockwell Automation strongly recommends the use of grounded
neutral systems for the following reasons:
• Controlled path for common mode noise current
• Consistent line to ground voltage reference, which minimizes
insulation stress
• Accommodation for system surge protection schemes
).
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 31
Chapter 3 System Configurations, Grounding, Application, and Control
or
Single Phase Loads
Single Phase Loads
Single Phase Loads
Three
Phase
Loads
Delta/Delta with Grounded Leg or Four-wire Connected Secondary Delta
Delta/Delta with Grounded Leg or Four-wire Connected Secondary Delta is a common configuration with no phase shift between input and
output. The grounded center tap provides a direct path for common mode current caused by the drive output.
Three-phase Open Delta with Single-phase Center Tapped
Three-phase Open Delta with Single-phase Center Tapped is a configuration providing a three-phase delta transformer with one side tapped.
This tap (the neutral) is connected to earth. The configuration is called the antiphase grounded (neutral) system. The open delta transformer
connection is limited to 58% of the 240V, single-phase transformer rating. Closing the delta with a third single-phase, 240V transformer
allows full rating for the two single-phase, 240V transformers. The phase leg opposite the midpoint has an elevated voltage when compared
to earth or neutral. The “hottest” high leg must be positively identified throughout the electrical system. It should be the center leg in any
switch, motor control, three-phase panel board, etc. The NEC requires orange color tape to identify this leg.
Ungrounded Secondary
Grounding the transformer secondary is essential to the safety of personnel and safe operation of the drive. Leaving the secondary floating
allows dangerously high voltages between the chassis of the drive and the internal power structure components. Exceeding the voltage
rating of the drive's input MOV (Metal Oxide Varistor) protection devices could cause the drive to fail. In all cases, the input power to the drive
should be referenced to ground. If the system is ungrounded, other general precautions such as a system level ground fault detector or
system level line to ground suppressor can be necessary or an isolation transformer must be considered with the secondary of the
transformer grounded. Refer to local codes regarding safety requirements. Also refer to the Wiring and Grounding Guidelines for Pulse Width
Modulated (PWM) AC Drives Installation Instructions, publication DRIVES-IN001
, Surge Protection MOVs and Common Mode Capacitors.
32 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Chapter 3 System Configurations, Grounding, Application, and Control
High Resistance Ground
Grounding the wye secondary neutral through a resistor is an acceptable method of grounding. Under a short circuit secondary condition,
any of the output phases to ground will not exceed the normal line to line voltage. This is within the rating of the MOV input protection
devices on the drive. The resistor is often used to detect ground current by monitoring the associated voltage drop. Since high frequency
ground current can flow through this resistor, be sure to properly connect the drive motor leads using the recommended cables and
methods. In some cases, multiple drives (that can have one or more internal references to ground) on one transformer can produce a
cumulative ground current that can trigger the ground fault interrupt circuit. Refer to the Wiring and Grounding Guidelines for Pulse Width
Modulated (PWM) AC Drives Installation Instructions, publication DRIVES-IN001
, Surge Protection MOVs and Common Mode Capacitors.
Application and Control
This section describes typical application and control strategies for different industries.
Automotive Industry
The Automotive industry uses low voltage (LV) AC drives in many different applications which can include the control of fans, pumps, press,
conveyor, and lifting applications, to name a few. It is very important to understand which process the drive will be applied to as the
environment and type of drive will vary in every application.
Review the motor cable distances. The use of an appropriate output device can be required based on cable distance, motor insulation, and
desired operating carrier frequency (PWM Frequency). See Wiring and Grounding Guidelines for Pulse Width Modulated (PWM) AC Drives
Installation Instructions, publication DRIVES-IN001
, for details on motor cable length restrictions.
Chemical and Specialty Chemical Industry
Typically, AC drives in the Chemical/Specialty Chemical industry include the control of pumps and fans. These applications are normally
variable torque (normal duty) rated and only require 115% overload for 1 minute. Positive displacement pumps have constant torque (heavy
duty) characteristics; therefore, requiring 150% overload for 1 minute.
Some pump manufacturers require lower RPM motors for their pumps which at a given horsepower will require more current than a typical
4-pole, 1800 RPM motor. The AC drive can have to be sized larger (de-rated) than the motor horsepower based on motor Full Load Amperes
(FLA).
Fan applications typically use 1800 RPM motors, but motor FLA should be reviewed to verify that de-rating of the AC drive is not required. Fan
applications should be reviewed for desired stopping times and inertia to determine if dynamic braking is required to prevent nuisance overvoltage tripping of the AC drive.
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 33
Chapter 3 System Configurations, Grounding, Application, and Control
Food and Beverage Industry
Typically, AC drives in the Food and Beverage industry include the control of pumps, agitators, conveyors, and basic material handling. Most
deal with large quantities of materials with tolerances in the seconds as opposed to msecs.
Coordination is only required on the fill/finish areas for items like labeling and packaging, and have low horsepower requirements. These
applications require speed and torque regulation based on the application requirements. Demand, burden, and load in the dough mixing
industry has lent to specific vendor preferences in the past (for example, technical drive variances can effect product quality).
Review the motor cable distances. The use of an appropriate output device can be required based on cable distance, motor insulation, and
desired operating carrier frequency (PWM Frequency). See Wiring and Grounding Guidelines for Pulse Width Modulated (PWM) AC Drives
Installation Instructions, publication DRIVES-IN001
, for details on motor cable length restrictions.
Forest Products and Converting Industry
Typically, AC drives in the Forest Products/Converting industries include the control of web applications. These applications require speed
and torque regulation based on the type of web process. In certain converting applications, such as Cut to Length, the knife drive
experiences high cyclic loading. In extreme cases, some applications require the drive to deliver a very high motoring load, and then switch
to a very high regenerative load, within a brief period of time. In this situation, perform a complete duty cycle analysis when selecting the
drive system components.
Review the motor cable distances. The use of an appropriate output device can be required based on cable distance, motor insulation, and
desired operating carrier frequency (PWM Frequency). See Wiring and Grounding Guidelines for Pulse Width Modulated (PWM) AC Drives
Installation Instructions, publication DRIVES-IN001
, for details on motor cable length restrictions.
Mining and Steel Industry
Typically, AC drives in the Mining and Steel industry include the control of conveyors and presses. These applications require speed and
torque regulation based on the application.
Review the motor cable distances. The use of an appropriate output device can be required based on cable distance, motor insulation, and
desired operating carrier frequency (PWM Frequency). See Wiring and Grounding Guidelines for Pulse Width Modulated (PWM) AC Drives
Installation Instructions, publication DRIVES-IN001
, for details on motor cable length restrictions.
Tire Manufacturing Industry
Typically, AC drives in the Tire Manufacturing industry include the control of extruders and conveyors. These applications require speed and
torque regulation based on the application requirements. Drives that are exposed to the tire manufacturing process, not mounted in a
control house, are exposed to carbon black. The most common use of carbon black is as a pigment and reinforcing phase in automobile
tires. Carbon black conducts heat away from the tread and belt area of the tire which reduces thermal damage, and helps to maintain the
reliability of the tire life. Carbon black is conductive and effects electronic circuits and assemblies by reducing the resistivity of the air and
the clearances around devices such as surface-mount components, as well as high-voltage assemblies such as bus bars.
Review the motor cable distances. The use of an appropriate output device can be required based on cable distance, motor insulation, and
desired operating carrier frequency (PWM Frequency). See Wiring and Grounding Guidelines for Pulse Width Modulated (PWM) AC Drives
Installation Instructions, publication DRIVES-IN001
For more information on the tire and rubber industry see the Control System Packaging for Corrosion Mitigation Design and Installation
Guideline, publication TIRE-RM001
34 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
.
, for details on motor cable length restrictions.
Chapter 3 System Configurations, Grounding, Application, and Control
Water and Waste Water Industry
Typical applications for AC drives in Water/Waste Water include the control of pumps and fans. These applications are normally variable
torque (normal duty) rated and only require 115% overload for 1 minute. Positive displacement pumps have constant torque (heavy duty)
characteristics; therefore, requiring 150% overload for 1 minute.
Some pump manufacturers require lower RPM motors for their pumps which at a given horsepower will require more current than a typical
4-pole, 1800 RPM motor. The AC drive can have to be sized larger (de-rated) than the motor horsepower based on motor Full Load Amperes
(FLA).
Fan applications typically use 1800 RPM motors, but motor FLA should be reviewed to verify that de-rating of the AC drive is not required. Fan
applications should be reviewed for desired stopping times and inertia to determine if dynamic braking is required to prevent nuisance overvoltage tripping of the AC drive.
Review the motor cable distances. The use of an appropriate output device can be required based on cable distance, motor insulation, and
desired operating carrier frequency (PWM Frequency). See Wiring and Grounding Guidelines for Pulse Width Modulated (PWM) AC Drives
Installation Instructions, publication DRIVES-IN001
For more information on the Water and Wastewater industry see the Control System Packaging for Corrosion Mitigation Design and
Installation Guideline, publication WWW-WP001
, for details on motor cable length restrictions.
.
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 35
Chapter 3 System Configurations, Grounding, Application, and Control
Notes:
36 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Chapter 4
Marine and Offshore Industry
The marine and offshore industry has a number of different conditions to be aware of due to the environment where it operates. This section
describes some of the things of which to be aware.
Typical Environmental Conditions
In the Marine and Offshore industry the AC drive can be installed either indoor (controlled), indoor (uncontrolled or ventilated), or outdoor
(above deck). With an outdoor and indoor (uncontrolled) installation, the environmental conditions that can be present are:
• Salt air
• Moisture and/or humidity
• Splashing seawater (above deck)
•High windows (above deck)
• Solar heating (above deck)
•UV light
Typical Hazardous Areas
In the marine and offshore industry the AC drive must comply with IEC Publication 60079, or other recognized standards, if it is installed in a
hazardous area. The following are examples of protective standards for hazardous areas.
• Intrinsically safe type (Ex i) (not suitable for high power)
• Flameproof (explosion-proof) type (Ex d)
• Increased safety type (Ex e)
• Pressurized or purged type (Ex p)
Consideration must be given to the flammability group and the temperature class of the equipment for suitability for the intended hazardous
area (see IEC Publication 60079-20). The following are examples of typical hazardous areas:
• Paint stores
• Battery rooms
• Oxygen-acetylene storage room
• Helicopter refueling facilities
• Other spaces defined by specification
• Areas defined by SVR, Part 5C, or the American Bureau of Shipping (ABS) rules for Offshore Drilling Units and/or Floating Production
Units
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 37
Chapter 4 Marine and Offshore Industry
Shielding by Enclosures
The degree of protection required by shipboard enclosure is established by ABS Steel Vessel Rules (or other rules having jurisdiction). Table 6
represents typical locations and their required levels of protection. The protection ratings are detailed in Abridged Descriptions of IEC
Enclosure Test Requirements on page 11.
Table 6 - Minimum Degree of Protection (2006)
(1)
Example of Location Condition of Location
Switchboards,
Distribution Boards,
Motor Control Centers,
Dry accommodation space
Dry control rooms
(3)
Danger of touching live
parts only
Control rooms
Machinery spaces above floor
(4)
plates
Steering gear rooms IP22 IP22 IP22 IP22 IP22 IP22 IP44
Refrigerating machinery room IP22 – IP22 IP22 IP22 IP22 IP44
Emergency machinery room IP22 IP22 IP22 IP22 IP22 IP22 IP44
Danger of dripping liquid
and/or moderate
mechanical damage
IP20
IP20 – IP20 IP20 IP20 IP20 IP20
IP22 – IP22 IP22 IP22 IP22 IP22
IP22 IP22 IP22 IP22 IP22 IP22 IP44
Generators
and Controllers
(2)
–
Motors
Lighting Fixtures
Heating Appliances
Transformers, Converters
IP20 IP20 IP20 IP20 IP20
Accessories
General store rooms IP22 – IP22 IP22 IP22 IP22 IP22
Pantries IP22 – IP22 IP22 IP22 IP22 IP44
Provision rooms IP22 – IP22 IP22 IP22 IP22 IP22
Bathrooms and showers
Machinery spaces below floor
plates
Increased danger of liquid
an/or mechanical damage
Closed fuel oil or lubricating oil
separator rooms
Ballast pump rooms
Refrigerated rooms – – IP44 – IP34 IP44 IP55
Increased danger of liquid
and mechanical damage
––––IP34IP44IP55
––IP44–IP34IP44
IP44 – IP44 – IP34 IP44
IP55
IP55
(5)
(5)
IP44 – IP44 IP44 IP34 IP44 IP55
Galleys and laundries IP44 – IP44 IP44 IP34 IP44 IP44
Shaft or pipe tunnels in double
bottom
Danger of liquid spray,
presence of cargo dust,
IP55 – IP55 IP55 IP55 IP55 IP56
serious mechanical
Holds for general cargo ––––IP55–IP55
damage, and/or aggressive
fumes
Open decks Exposure to heavy seas IP56 – IP56 – IP55 IP56 IP56
Bilge wells Exposure to submersion––––IPX8–IPX8
(1) “Accessories” include switches, detectors, junction boxes, etc.
(2) Empty spaces shown with “–” indicate installation of electrical equipment is not recommended.
(3) For the purpose of this Table, the wheelhouse can be categorized as a “dry control room” and consequently, the installation of IP20 equipment would suffice therein provided that:
(a) the equipment is located as to preclude being exposed to steam, or dripping/spraying liquids emanating from pipe flanges, valves, ventilation ducts and outlets, etc., installed
in its vicinity, and (b) the equipment is placed to preclude the possibility of being exposed to sea or rain.
(4) (2006) See ABS Publication Rules for Building and Classing Steel Vessel Rules (2011), Part 4, Vessel Systems and Machinery, 4-8-3/1.11.2, where the equipment is located within areas
protected by local fixed pressure water-spraying or water-mist fire extinguishing system and its adjacent areas.
(5) Socket outlets are not to be installed in machinery spaces below the floor plate, enclosed fuel and lubricating oil separator rooms or spaces requiring certified safe equipment.
Table 6 © ABS. Reproduced and distributed with permission of ABS.
38 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Chapter 4 Marine and Offshore Industry
Protecting Electronic Modules During Installation
Because of direct exposure to the process environment during installation, the electronic modules can be exposed to contaminants and are
susceptible to corrosion damage. After this exposure, failures can occur even after the electronic modules are sealed within enclosures. To
minimize the potential for failure, follow these precautions.
• Complete the construction and wiring (as much as possible) of the control rooms before the modules are unpacked.
• Minimize the time modules remain in an unprotected area.
• Always use protective bags for module storage.
• Keep doors to control rooms and enclosures closed unless opening the door is a necessity.
Power Distribution
You must evaluate and configure the power distribution systems to provide optimum performance for the AC drive. See System
Configurations and Grounding below.
For more information, see the Wiring and Grounding Guidelines for Pulse Width Modulated (PWM) AC Drives Installation Instructions,
publication DRIVES-IN001
.
System Configurations and Grounding
The type of transformer and the connection configuration feeding a drive plays an important role in the performance and safety of the drive.
The following is a brief description of some of the more common configurations and a discussion of their qualities and differences.
Ungrounded Power
For shipboard applications the power system is typically ungrounded (3-wire). This allows for continuity of service under single line-toground fault conditions, particularly in distribution systems supplying critical service loads to the ship. Ungrounded systems shall require
the removal of the drives MOV jumpers and Y caps. To avoid damage to the drive under spike voltage conditions, use an isolation
transformer. Provide a means to continuously monitor and indicate the state of the insulation-to-ground for drives used for electric
propulsion systems and emergency power systems, and drives that are isolated by transformers, motor-generators, or other devices.
Solidly grounded designs should be limited to systems supplying noncritical loads, such as normal lighting, galley circuits, etc.
The hull of a vessel must not carry current as a conductor.
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 39
Chapter 4 Marine and Offshore Industry
Ungrounded Secondary
Application and Control
Typically, AC drives in the Marine and Offshore industry include the control of crane applications, winch applications, and secondary
propulsion systems.
System Design and Implementation Considerations
• To determine sizing of your generator sets, perform a complete evaluation of the system demands for steady state, as well as peak
loading and inrush conditions.
• For PWM AC Drive applications single point grounding where the VFD ground is preferred to be directly routed back to Wye of supply
transformer or zig-zag transformer. (Check with local codes, marine, and MIL specifications.)
• When non-linear loads (such as AC adjustable speed drives) are part of the connected load, harmonics and power factor will also
affect generator set sizing.
• To estimate Voltage Total Harmonic Distortion (V_THD) as a function of AC line side converter topology, consider these factors:
-generator Z
- number of parallel generator sets
- single kVA oversize
Low harmonic adjustable speed drive supplies can significantly reduce generator kVA oversizing.
• Systems powered by a local generator typically require more design considerations than systems powered by a large utility.
• Synchronous generators have a limited capability to absorb real or reactive power (leading), as well as harmonics.
• Generators produce harmonics. The pitch of the generator determines the frequency and level of the harmonics.
• Establish the single line for the system and define the load requirements prior to selecting a generator.
• Document and review operating scenarios and sequences of operation in regard to the different contingencies that can occur. This
includes commissioning when the system is not fully functional, and therefore, operating in a non-standard mode.
• Include the drive and generator suppliers in system design and development from the beginning and throughout the project. Then if
design changes occur, it will be easier for the drive and generator suppliers to make changes to help optimize the system.
• Non-linear loads (such as AC adjustable speed drives) require additional design and implementation consideration when applied on
local generator supplies. The limited capacity and high reactance of these local sources exaggerate the effects that occur on all
systems, but are significantly reduced on higher capacity, more diverse supplies.
• The use of radios on ships and cranes and radars aboard ships introduces the risk of electromagnetic interference (EMI) problems for
PWM AC Drives which could become susceptible to an intense electromagnetic environment (EME) and malfunction. Additional
hardening against electromagnetic environmental effects (E3) can be needed including EMI shielding of and bonding of cables, EMI
shielded/bonded enclosures and equipment, use of high performance line filtering. For procedures and guidance to address these
requirements, refer to publications:
- MIL-STD-1310H Shipboard Bonding, Grounding, and other Techniques for Electromagnetic Compatibility, Electromagnetic Pulse
(EMP) Mitigation, and Safety
- DNV Commercial Ship Guidelines for EMC control CN45-1
- IEEE 45.3-2012 IEEE Recommended Practice for Shipboard Electrical Installations - Systems Engineering
For more information, refer to the IEEE
Drives.
publication, Electrical System Design of Local Generator Applications Involving Adjustable Speed
40 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Appendix A
Sample Drive Installation Requirements
These sample checklists can be used in different phases of a project (design,
pre-install, and post-install) to help ensure the installation is done per recommendations and requirements. See Appendix B
industry-specific, recommendations and requirements.
Design Checklist
Checklist of common items to be considered when designing any system with our standard drives.
AC Supply Source
Identify or select distribution transformer grounding & note how drive power jumpers should be configured
– For unbalanced, ungrounded, or resistive grounded distribution systems:
• Note to configure power jumpers in the open position or removed from the circuit
• Consider adding alternate surge suppression in front of the drive (required for UL)
– For solidly grounded distribution systems (preferred):
• Note to configure power jumpers in the closed position or in circuit
– For unknown systems:
• Note to identify grounding and configure jumpers accordingly
for additional,
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 41
Appendix A Sample Drive Installation Requirements
Input Power Conditioning
Verify that a Rockwell Automation™ 1321 type or equivalent Isolation Transformer (a grounded secondary supply voltage source) is
installed.
Verify that the Isolation Transformer kVA size does not exceed 10 times the kVA rating of the drive.
If the transformer exceeds 10 times the kVA rating of drives without DC Link Chokes or 20 times the kVA rating of drives with DC
–
Link Chokes, add additional impedance in front of the drive (a line reactor is most common).
Verify that the XO on the secondary of the Isolation Transformer is solidly grounded (less than 1Ω).
Line reactors are required if an Isolation Transformer is not used. No device shall be wired between the line reactor (secondary side)
and the drive.
Grounding and Bonding
Verify the paint is scraped away down to bare metal when mounting the Ground Bar.
Verify a ground wire is run from the drive (PE) ground terminal directly to the enclosure ground bar using specified gauge wire.
Verify a ground wire is run from the Motor directly to the Drive.
Verify multiple Sub-Plates are bonded together using braided metal straps.
For Unbalanced, Ungrounded, or Resistive Grounded Distribution Systems:
– Remove protective MOVs from the drive.
– Remove Common Mode Capacitors from the drive.
Motor Cable Wiring
Verify the motor cable is the shielded type.
The motor cable shield must be connected at both the Drive end and at the Motor end.
Verify the mechanical brake cable shield is terminated to the enclosure ground bar—NOT to the drive.
Verify that motor cable lengths adhere to the specifications outlined in Appendix A of publication DRIVES-IN001
Encoder Feedback Signal Wiring – Rockwell Automation’s Recommended Shielding Technique
Verify the type of Encoder Cable being used.
Verify Encoder Cable wiring is NOT within 304 mm (12 in.) of motor power wiring and/or motor brake wiring within the enclosure.
Verify Encoder Cable wiring outside the enclosure is run in raceways using dividers or with separate conduit runs.
Dynamic Brakes
Verify the dynamic brake is installed and wired to (BR+) and (BR-) on the drive.
Verify the dynamic brake cable type is “twisted pair” terminated to the enclosure ground bar—NOT the drive.
Wire Routing
Verify there is separation between High and Low voltage wiring, and that wires cross at 90° angles.
42 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Appendix A Sample Drive Installation Requirements
Surge Suppression
Verify Surge Suppressors are installed on all coils, including contactors, solenoids, relays, and brake coils, to reduce transients that can
interfere with the drive(s).
Environmental Considerations
Equipment installation must meet the basic environmental requirements as outlined in Chapter 1
considerations outlined in Chapter 2
of this manual. See the product manual for specific installation requirements.
, and the industry related installation
Pre-Installation Checklists
Items to check prior to installation of standard drives.
AC Supply SourceInput Power Conditioning
Confirm distribution transformer grounding & drive power jumper configuration
– For unbalanced, ungrounded, or resistive grounded distribution systems:
• Configure power jumpers in the open position or removed from the circuit
– For solidly grounded distribution systems:
• Configure power jumpers in the closed position or in circuit
Identify the distribution transformer kVA size.
If the transformer exceeds 10 times the kVA rating of drives without DC Link Chokes or 20 times the kVA rating of drives with DC
–
Link Chokes, add additional impedance in front of the drive (a line reactor is most common).
– The kVA should at least meet the full load kVA of the rating of the drive on a non-Regen drive.
For PowerFlex™ 755TL/TR/TM drives, the supply system kVA must be equal to or greater than the product-related kW, and the
–
system impedance must be less than 10%. System impedance is calculated as
{System Impedance - (PowerFlex 755T kVA / Transformer kVA) x Transformer % impedance}
Validate supplemental equipment that will be on the same power as the drive (PFCCs, other switching devices, passive harmonic
filters)
– Implement necessary isolation as required
Surge Suppression
Identify all coils, including contactors, solenoids, relays, and brake coils, so surge suppressors can be installed to reduce transients that
can interfere with the drive(s) [for both control and line power, for example, mechanical brakes operating at 480V].
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 43
Appendix A Sample Drive Installation Requirements
Grounding and Bonding
Verify the paint is scraped away down to bare metal when mounting the Ground Bar.
Verify a ground wire is run from the drive (PE) ground terminal directly to the enclosure ground bar using specified gauge wire.
Verify a ground wire is run from the Motor directly to the Drive.
Verify multiple Sub-Plates are bonded together using braided metal straps.
Verify PE grounds are located properly.
This has the input power ground located on the terminal/connection closer to the input power wiring and the motor cable ground
–
located on the terminal/connection closer to the output power wiring.
Mounting Considerations and Environment
Equipment installation must meet the basic environmental requirements as outlined in Chapter 1
product manual for specific installation requirements.
Ensure the minimum mounting clearances will be met on the drive.
Ensure drive enclosure rating will protect drive from relevant physical contaminants and corrosive gases
IP00, IP20, & NEMA/UL Open Type PowerFlex Series drives must be mounted in a clean, dry location. Contaminants such as oils,
corrosive vapors, and abrasive debris must be kept out of the enclosure. These enclosures are intended for indoor use primarily to
–
provide a degree of protection against contact with enclosed equipment. These enclosures offer no protection against airborne
contaminants.
– IP54 enclosures provide a degree of protection from dirt, dust, oil, and other non-corrosive material as well as splashing water.
and Chapter 2 of this manual. See the
Control and Signal Cabling
Verify there is separation between High and Low voltage wiring, and that wires cross at 90° angles.
See the table in the Wire Routing section of Chapter 4 in the Wiring and Grounding for Pulse Width Modulated (PWM) AC Drives
–
Installation Instructions, publication DRIVES-IN001
.
Dynamic Brakes
Verify the dynamic brake is installed and wired to (BR+) and (BR-) on the drive.
Verify the dynamic brake cable type is “twisted pair” terminated to the enclosure ground bar—NOT the drive.
Verify dynamic brake cable length will not exceed recommendations based on drive frame size
Motor Cable Wiring
Verify the motor cable is the shielded type.
The motor cable shield must be connected at both the Drive end and at the Motor end.
Verify the mechanical brake cable shield is terminated to the enclosure ground bar—NOT to the drive.
Verify that motor cable lengths adhere to the specifications outlined in Appendix A of publication DRIVES-IN001
insulation rating will be sufficient for cable length. If not, implement on of the solutions recommended in the tables.
44 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
to ensure motor
Appendix A Sample Drive Installation Requirements
Encoder Feedback Signal Wiring – Rockwell Automation’s Recommended Shielding Technique
Verify the type of Encoder Cable being used.
Verify Encoder Cable wiring is NOT within 304 mm (12 in.) of motor power wiring and/or motor brake wiring within the enclosure.
Verify Encoder Cable wiring outside the enclosure is run in raceways using dividers or with separate conduit runs.
Validate encoder type is compatible with feedback module
Post Installation Checklists
Items to recheck after installation of standard drives.
AC Supply Source
Confirm distribution transformer grounding & drive power jumper configuration
– For unbalanced, ungrounded, or resistive grounded distribution systems:
• Configure power jumpers in the open position or removed from the circuit
– For solidly grounded distribution systems:
• Configure power jumpers in the closed position or in circuit
Input Power Conditioning
Identify the distribution transformer kVA size.
If the transformer exceeds 10 times the kVA rating of drives without DC Link Chokes or 20 times the kVA rating of drives with DC
–
Link Chokes, add additional impedance in front of the drive (a line reactor is most common).
– The kVA should at least meet the full load kVA of the rating of the drive on a non-Regen drive.
For PowerFlex 755TL/TR/TM drives, the supply system kVA must be equal to or greater than the product-related kW, and the
–
system impedance must be less than 10%. System impedance is calculated as:
{System Impedance - (PowerFlex 755T kVA / Transformer kVA) x Transformer % impedance}
Validate supplemental equipment that will be on the same power as the drive (PFCCs, other switching devices, passive harmonic filters)
– Implement necessary isolation as required
Surge Suppression
Verify Surge Suppressors are installed on all coils, including contactors, solenoids, relays, and brake coils, to reduce transients that can
interfere with the drive(s) [for both control and line power, ie mechanical brakes operating at 480V].
Grounding and Bonding
Verify the paint is scraped away down to bare metal when mounting the Ground Bar.
Verify a ground wire is run from the drive (PE) ground terminal directly to the enclosure ground bar using specified gauge wire.
Verify a ground wire is run from the Motor directly to the Drive.
Verify multiple Sub-Plates are bonded together using braided metal straps.
Verify PE grounds are located properly.
This has the input power ground located on the terminal/connection closer to the input power wiring and the motor cable ground
–
located on the terminal/connection closer to the output power wiring.
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 45
Appendix A Sample Drive Installation Requirements
Mounting Considerations and Environment
Verify the ambient temperature will not exceed the drive rating unless proper derating is applied.
Ensure the minimum mounting clearances will be met on the drive.
Ensure drive enclosure rating will protect drive from relevant physical contaminants and corrosive gases:
IP00, IP20, & NEMA/UL Open Type PowerFlex Series drives must be mounted in a clean, dry location. Contaminants such as oils,
corrosive vapors, and abrasive debris must be kept out of the enclosure. These enclosures are intended for indoor use primarily
–
to provide a degree of protection against contact with enclosed equipment. These enclosures offer no protection against airborne
contaminants.
– IP54 enclosures provide a degree of protection from dirt, dust, oil, and other non-corrosive material as well as splashing water.
Control and Signal Cabling
Verify there is separation between High and Low voltage wiring, and that wires cross at 90° angles.
See the table in the Wire Routing section of Chapter 4 in the Wiring and Grounding for Pulse Width Modulated (PWM) AC Drives
–
Installation Instructions, publication DRIVES-IN001
.
Dynamic Brakes
Verify the dynamic brake is installed and wired to (BR+) and (BR-) on the drive.
Verify the dynamic brake cable type is “twisted pair” terminated to the enclosure ground bar—NOT the drive.
Verify dynamic brake cable length will not exceed recommendations based on drive frame size
Motor Cable Wiring
Verify the motor cable is the shielded type.
The motor cable shield must be connected at both the Drive end and at the Motor end.
Verify the mechanical brake cable shield is terminated to the enclosure ground bar—NOT to the drive.
Verify that motor cable lengths adhere to the specifications outlined in Appendix A of publication DRIVES-IN001
insulation rating sufficient for cable length. If not, implement on of the solutions recommended in the tables.
to ensure motor
Encoder Feedback Signal Wiring – Rockwell Automation’s Recommended Shielding Technique
Verify the type of Encoder Cable being used.
Verify Encoder Cable wiring is NOT within 304 mm (12 in.) of motor power wiring and/or motor brake wiring within the enclosure.
Verify Encoder Cable wiring outside the enclosure is run in raceways using dividers or with separate conduit runs.
Validate encoder type is compatible with feedback module
46 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Appendix B
Sample Requirements and Enclosure Specifications for Specific Industry
Types
This section contains sample checklists to help you prepare industry-specific information for installation of drives for selected industries.
Requirements that are common to enclosures and covered in other parts of this manual also apply to these enclosures. Information on other
industries, which do not have specific enclosure information for this list, are described in other parts of this manual. Industries that are not
listed specifically in this appendix and covered in the rest of this manual include: Chemical/Specialty Chemical, Food and Beverage, Marine
and Offshore, Tire Manufacturing, and Water/Waste Water industry. As always, these are not comprehensive lists and are meant to help you
consider the requirements for your specific industry and location.
Top ic Pa ge
Automotive Industry 47
Forest Products/Converting (Pulp Paper Products)
Industry) industry
Metals Industry 49
Mining Process Products 50
Oil, Gas, and Chemical Products 51
Open Pit Mining Products 52
48
Automotive Industry
In addition to the items that apply to all standard drives (see Appendix A), the following is a sample of the information that can be attached to
an Automotive Manufacturer's RFQ or Purchase Order to a machine supplier, panel builder, or system integrator to help confirm that the
supplier follows the recommendations that are presented in this document. Details for your specific location can vary.
Enclosure Construction
• All enclosures shall meet or exceed NEMA 12 for North America or IP54 for all other regions.
Welded
• Welded IP54 / NEMA 12 enclosures are acceptable for all applications and areas.
• Enclosures shall be made of cold rolled steel, painted with multiple layers, including primer and finish.
• Welds must be continuous on all seams, cleaned, and ground smooth before painting.
• The enclosure must have a solid bottom and top.
Grounding
• The ground bar shall be one solid piece and located along the bottom of the enclosure.
• All enclosures must be designed to meet the requirements of NFPA79 and the latest National Electrical Code.
• Sensitive electronic devices require supplemental grounding techniques to reduce the effects of EMI
• A braided copper bonding jumper shall be installed to bond the main enclosure panel to any enclosure doors to be compliant with
NFPA 70 Chapter 17.
• All ground connection points to the enclosure shall have the paint removed at the point of contact.
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 47
Appendix B Sample Requirements and Enclosure Specifications for Specific Industry Types
Frame and Panel
• The enclosure must have solid plates installed on the top and bottom.
• Solid is preferable. Multi piece gland plates can be acceptable as long as they are properly sealed.
• All ferrous metal parts on the enclosure shall be painted or plated to help prevent rust.
Cooling
• Heat calculations must be performed and submitted with approval drawings for each enclosure.
• Acceptable cooling methods for include:
- Conductive heat dissipation shall be used if the heat generated can be effectively transmitted through the sheet metal of the
enclosure.
- Heat exchangers or air conditioners shall be used to remove heat when conductive dissipation is not sufficient.
Forest Products/Converting (Pulp Paper Products) Industry
In addition to the items that apply to all standard drives (see Appendix A), the following is a sample of the information that can be attached to
a Paper Manufacturer’s RFQ or Purchase Order to a machine supplier, panel builder, or system integrator to help ensure that the supplier
follows the recommendations that are presented in this document. Details for your specific location can vary.
Enclosure Construction
• All enclosures shall meet or exceed IP54. IP54 design that circulates external air through IP54 rated filters is NOT acceptable. These
include enclosures rated IP55, IP62, IP64, IP67, for example.
• All cable entry points shall be designed to use cord grips or cable entry management systems that seal each cable or conductor to
meet or exceed an IP54 rating.
• All conduit / wireway entries shall be designed to be sealed with fire block or other conduit seal compound.
• Silicon-based sealants shall not be used.
Welded
• Welded IP54 / NEMA 12 enclosures are acceptable for all applications and areas.
• Enclosures shall be made of cold rolled steel, painted with multiple layers, including corrosion-resistant primer and finished with a
baked-on paint (for example, enamel, polyester).
• Welds must be continuous on all seams, cleaned, and ground smooth before painting.
• The enclosure must have a solid bottom and top.
Frame and Panel
• IP54 rated frame and panel enclosures, Rittal, Hoffman Proline 2, or similar, are acceptable in locations where exposure to mechanical
damage from moving vehicles such as, tow motors, fork trucks, or carts is not possible.
• The enclosure must have solid plates installed on the top and bottom.
• Solid is preferable. Multi piece gland plates can be acceptable as long as they are properly sealed.
Gaskets
• Gaskets must be neoprene rubber for chemical and acid / base resistance. Gaskets must be applied in a channel to help ensure that
the seal remains in place.
48 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Appendix B Sample Requirements and Enclosure Specifications for Specific Industry Types
• Spray-on foam gasket material, as is used in many modular enclosure systems and some welded solutions, is acceptable if it is a
material that is rated for corrosive gas rich environments.
• Silicone rubber-based gasket material shall not be used.
Cooling
• Heat calculations must be performed and submitted with approval drawings for each enclosure.
• Acceptable cooling methods for include:
- Conductive heat dissipation shall be used if the heat generated can be effectively transmitted through the sheet metal of the
enclosure.
- Heat exchangers or air conditioners shall be used to remove heat when conductive dissipation is not sufficient. The heat
exchangers / air conditioners must be sealed so that air external to the enclosure is not mixed with internal air.
- Heat exchanger / air conditioners shall be conform coated IP66 / NEMA 4 versions of these units.
Marine and Offshore Industry
The marine and offshore industry has a number of requirements in addition to those described in Appendix A. See Chapter 4 for detailed
information.
Metals Industry
In addition to the items that apply to all standard drives (see Appendix A: Sample Drive Installation Requirements, the following is a sample of
the information that can be attached to a Metal Manufacturer's RFQ or Purchase Order to a machine supplier, panel builder, or system
integrator to help ensure that the supplier follows the recommendations that are presented in this document. Details for your specific
location can vary.
Enclosure Construction
• All enclosures shall meet or exceed NEMA12. Additional filtering or the use of a positive pressure system is also required to help
protect against particulate contaminants.
• All cable entry points shall be designed to use cord grips or cable entry management systems that seal each cable or conductor to
meet or exceed a NEMA12 rating.
• All conduit / wireway entries shall be designed to be sealed with fire block or other conduit seal compound.
Welded
• Welded NEMA 12 enclosures are acceptable for all applications and areas.
• Enclosures shall be made of cold rolled steel, painted with multiple layers, and finished with a baked-on paint (for example, enamel,
polyester).
• Welds must be continuous on all seams, cleaned, and ground smooth before painting.
• The enclosure must have a solid bottom and top.
Frame and Panel
• NEMA 12 rated frame and panel enclosures, Rittal, Hoffman Proline 2, or similar, are acceptable in locations where exposure to
mechanical damage from moving vehicles such as, tow motors, fork trucks, or carts is not possible.
• The enclosure must have solid plates installed on the top and bottom.
• Solid is preferable. Multi piece gland plates can be acceptable as long as they are properly sealed.
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 49
Appendix B Sample Requirements and Enclosure Specifications for Specific Industry Types
Gaskets
• Gaskets must be aligned with a NEMA 12 rating.
Cooling
• Heat calculations must be performed and submitted with approval drawings for each enclosure.
• Acceptable cooling methods for include:
- Conductive heat dissipation shall be used if the heat generated can be effectively transmitted through the sheet metal of the
enclosure.
- Heat exchangers or air conditioners shall be used to remove heat when conductive dissipation is not sufficient. The heat
exchangers / air conditioners must be either filtered or bringing in external air.
Mining Process Products
In addition to the items that apply to all standard drives (see Appendix A:
Sample Drive Installation Requirements
Purchase Order to a machine supplier, panel builder, or system integrator to help ensure that the supplier follows the recommendations that
are presented in this document. This sample is focused on the Process aspect of a mine. Details for your specific location can vary.
), the following is a sample of the information that can be attached to a Mining Organization's RFQ or
Enclosure Construction
• All enclosures shall meet or exceed IP12. Additional filtering or the use of a positive pressure system is also required to help protect
against particulate contaminants.
• All cable entry points shall be designed to use cord grips or cable entry management systems that seal each cable or conductor to
meet or exceed an IP12 rating.
• All conduit / wireway entries shall be designed to be sealed with fire block or other conduit seal compound.
Welded
• Welded IP12 enclosures are acceptable for all applications and areas.
• Enclosures shall be made of cold rolled steel, painted with multiple layers, and finished with a baked-on paint (for example, enamel,
polyester).
• Welds must be continuous on all seams, cleaned, and ground smooth before painting.
• The enclosure must have a solid bottom and top.
Frame and Panel
• IP12 rated frame and panel enclosures, Rittal, Hoffman Proline 2, or similar, are acceptable in locations where exposure to mechanical
damage from moving vehicles such as, tow motors, fork trucks, or carts is not possible.
• The enclosure must have solid plates installed on the top and bottom.
• Solid is preferable. Multi piece gland plates can be acceptable as long as they are properly sealed.
Gaskets
• Gaskets must be made of material to meet the IP12 rating.
50 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Appendix B Sample Requirements and Enclosure Specifications for Specific Industry Types
Cooling
• Heat calculations must be performed and submitted with approval drawings for each enclosure.
• Acceptable cooling methods for include:
- Conductive heat dissipation shall be used if the heat generated can be effectively transmitted through the sheet metal of the
enclosure.
- Heat exchangers or air conditioners shall be used to remove heat when conductive dissipation is not sufficient.
- Proper filtering or positive air pressure must be used on any air exchange that will occur for cooling.
Oil, Gas, and Chemical Products
In addition to the items that apply to all standard drives (see Appendix A: Sample Drive Installation Requirements), the following is a sample
of the information that can be attached to an Oil/Gas/Chemical Producer's RFQ or Purchase Order to a machine supplier, panel builder, or
system integrator to help ensure that the supplier follows the recommendations that are presented in this document. Details for your
specific location can vary.
Enclosure Construction
• All enclosures shall meet or exceed IP54. IP54 design that circulates external air through IP54 rated filters is NOT acceptable. These
include enclosures rated IP55, IP62, IP64, IP67, for example.
• All cable entry points shall be designed to use cord grips or cable entry management systems that seal each cable or conductor to
meet or exceed an IP54 rating.
• All conduit / wireway entries shall be designed to be sealed with fire block or other conduit seal compound.
• Silicon-based sealants shall not be used.
• Enclosures shall meet IEEE C37.20.7 for arc resistance
• Enclosures shall be certified to meet Class 1 Div 1 for hazardous locations
• Enclosures and equipment shall have Seismic certification
• Enclosures shall meet marine standards ABS, DNV, and Lloyd's
Welded
• Welded IP54 / NEMA 12 enclosures are acceptable for all applications and areas.
• Enclosures shall be made of cold rolled steel, painted with multiple layers, including corrosion-resistant primer and finished with a
baked-on paint (for example, enamel, polyester).
• Welds must be continuous on all seams, cleaned, and ground smooth before painting.
• The enclosure must have a solid bottom and top.
Frame and Panel
• IP54 rated frame and panel enclosures, Rittal, Hoffman Proline 2, or similar, are acceptable in locations where exposure to mechanical
damage from moving vehicles such as, tow motors, fork trucks, or carts is not possible.
• The enclosure must have solid plates installed on the top and bottom.
• Solid is preferable. Multi piece gland plates can be acceptable as long as they are properly sealed.
Gaskets
• Gaskets must be neoprene rubber for chemical and acid / base resistance. Gaskets must be applied in a channel to help ensure that
the seal remains in place.
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 51
Appendix B Sample Requirements and Enclosure Specifications for Specific Industry Types
• Spray-on foam gasket material, as is used in many modular enclosure systems and some welded solutions, is acceptable if it is a
material that is rated for corrosive gas rich environments.
• Silicone rubber-based gasket material shall not be used.
Temperature Control
• Heat calculations must be performed and submitted with approval drawings for each enclosure.
• Acceptable cooling methods for include:
- Conductive heat dissipation shall be used if the heat generated can be effectively transmitted through the sheet metal of the
enclosure.
- Heat exchangers or air conditioners shall be used to remove heat when conductive dissipation is not sufficient. The heat
exchangers / air conditioners must be sealed so that air external to the enclosure is not mixed with internal air.
- Heat exchanger / air conditioners shall be conform coated IP66 / NEMA 4 versions of these units.
- Heating elements shall be fused and sized to heat the enclosure when the equipment is not producing heat from -50C up to the
equipment's minimum operating temperature.
Open Pit Mining Products
In addition to the items that apply to all standard drives (see Appendix A: Sample Drive Installation Requirements), the following is a sample
of the information that can be attached to a Mining Organization's RFQ or Purchase Order to a machine supplier, panel builder, or system
integrator to help ensure that the supplier follows the recommendations that are presented in this document. This sample is focused on an
Open Pit application. Details for your specific location can vary.
Enclosure Construction
• All enclosures shall meet or exceed IP12. Additional filtering or the use of a positive pressure system is also required to protect against
particulate contaminants.
• All cable entry points shall be designed to use cord grips or cable entry management systems that seal each cable or conductor to
meet or exceed an IP12 rating.
• All conduit / wireway entries shall be designed to be sealed with fire block or other conduit seal compound.
• The overall enclosure and gasketing construction must made of material that is built to withstand UV exposure.
Welded
• Welded IP12 enclosures are acceptable for all applications and areas.
• Enclosures shall be made of cold rolled steel, painted with multiple layers, and finished with a baked-on paint (for example, enamel,
polyester).
• Welds must be continuous on all seams, cleaned, and ground smooth before painting.
• The enclosure must have a solid bottom and top.
52 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Appendix B Sample Requirements and Enclosure Specifications for Specific Industry Types
Frame and Panel
• IP12 rated frame and panel enclosures, Rittal, Hoffman Proline 2, or similar, are acceptable in locations where exposure to mechanical
damage from moving vehicles such as, tow motors, fork trucks, or carts is not possible.
• The enclosure must have solid plates installed on the top and bottom.
• Solid is preferable. Multi piece gland plates can be acceptable as long as they are properly sealed.
Gaskets
• Gaskets must be made of material to withstand the temperature demands and UV exposure. Gaskets must be applied in a channel to
help ensure that the seal remains in place.
• Spray-on foam gasket material, as is used in many modular enclosure systems and some welded solutions, is acceptable if it is a
material that is rated for the necessary temperature and UV environments.
Cooling
• Heat calculations must be performed and submitted with approval drawings for each enclosure.
• Acceptable cooling methods for include:
- Conductive heat dissipation shall be used if the heat generated can be effectively transmitted through the sheet metal of the
enclosure.
- Heat exchangers or air conditioners shall be used to remove heat when conductive dissipation is not sufficient.
- Proper filtering or positive air pressure must be used on any air exchange that will occur for cooling.
- Heating elements shall be fused and sized to heat the enclosure when the equipment is not producing heat from -40C up to the
equipment's minimum operating temperature.
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 53
Appendix B Sample Requirements and Enclosure Specifications for Specific Industry Types
Notes:
54 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Numerics
4X rating, indicates corrosion resistance 10
A
adjustable speed drives 5
atmospheric contaminants
9
C
conformal coating 9
contaminants and conditions
by industry
acidic rain 23
active organic nitrogen 22, 23
biological elements 23
carbon 23
carbon black 23
Carbon monoxide 23
carbon monoxide 22, 23
chlorine 22, 23
chlorine dioxide 22, 23
cleaning and other chemicals 22
cleaning solvents 23
fuel oil 23
high moisture or humidity 22
high-pressure wash down 22
hose-directed water 22
Hydrocarbons 22, 23
hydrocarbons 22
hydrochloric acid 23
Hydrogen fluoride 22
hydrogen fluoride 22
Hydrogen sulfide 22, 23
hydrogen sulfide 22
inorganic dust 23
mercaptans 23
Moisture or humidity 23
oxides of nitrogen 22
phosphates 22
pickle line acid 23
salt air 23
sea water 23
sulfur dioxide 22
by location
airborne contaminant limited by ventilation system and filters 23
clean air control room 23
corrosive or combustible gasses 23
dust 23
fan-ventilated areas 23
maximum and minimum ambient temperatures 23
moisture content 23
Index
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 55
Index
non-conditioned plant floor areas 23
not typical temperature regulated 23
proximity to the ocean or salt air 23
rain 23
seismic activity 23
shipboard machinery rooms 23
size of airborne contaminant 23
snow 23
temperature regulated 23
uncontrolled moisture content 23
wash-down areas 23
wind 23
corrosion failures
corrosion resistance rating, 4X
9
D
degree of protection
against liquid ingress
enclosures 10
IEC enclosure classification
Nitrile seals
Viton seals 10
duty ratings
continuous
non-periodic
periodic 25
short-time
10
26
26
10
26
10
11
E
enclosue selection considerations 21
enclosure cooling system
enclosure descriptions
for non-hazardous locations
selection criteria for non-hazardous locations
Type 1 – flush mounting
Type 1 – general purpose surface mounting 17
Type 12 – dusttight industrial use
Type 13 – oiltight
Type 3 – rainproof dusttight
Type 3R – rainproof
Type 4 – watertight
Type 4X – non-metallic, corrosion-resistant
Type 6P – for prolonged submersion at a limited depth
Type 7 – for hazardous gas locations
Type 9 – for hazardous dust locations
enclosure ratings
enclosure tests, abridged descriptions
IEC, protection against
access to hazardous parts 11
solid foreign objects 12
water 13
NEMA
air pressure test 15
corrosion protection 15
drip test 14
external icing test 15
hosedown Test 15
indoor dust test 15
oil exclusion test 15
25
19
17
18
18
17
17
17
18
18
9
20
17
18
56 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
outdoor dust test 14
rain test 14
rod entry test 14
rust resistance test 15
UL 698
dust penetration test 16
explosion test 16
hydrostatic test 16
temperature test 16
temperature test with dust blanket 16
enclosures offered by Rockwell Automation
for hazardous locations
environmental considerations 9
20
I
IEC enclosure classification 11
N
Nitrate seals 10
Index
P
pulse width modulated drives 5
5
PWM
R
recommended standards publications
ABS
rules for building and classing steel vessels 2009, Part 4 7
CSA Standard C22.2
No. 0 6
No. 0.4 6
No. 14 6
No. 182.4 6
No. 25 6
No. 26 6
No. 40 6
No. 76 6
No. 94 6
IEC publication
529 7
60079 7
60079-20 7
60529 7
6
IEEE 45
ISA-71.04-2013 7
NEMA standards publication
No. 250 5
No. ICS6 5
NFPA
496 6
70 6
70e 6
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 57
Index
79 6
SAE HS 1738
Underwriters Laboratories
6
UL 1203 5
UL 1773 6
UL 1863 6
UL 2279 6
UL 414 5
UL 497 5
UL 50 5
UL 508A 5
UL 50E 5
UL 870 5
UL 94 5
S
seals
10
Nitrile
Viton
selection of an enclosure 21
standards organizations
10
international
North American
10
9
T
temperature
highest permissible
rise considerations
typical environmental contaminants
marine and offshore industry
25
25
high windows (above deck) 37
moisture and/or humidity 37
salt air 37
solar heating (above deck) 37
splashing seawater (above deck) 37
UV light 37
U
U.S. National Electrical Code
Class I, Groups C, D
Class II, Groups E, F, G
18
18
V
variable frequency drives 5
Viton seals
10
58 Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020
Industry Installation Guidelines for Pulse Width Modulated (PWM) AC Drives Application Techniques
Additional Resources
These documents contain additional information concerning related products from Rockwell Automation.
Resource Description
Wiring and Grounding Guidelines for Pulse Width Modulated (PWM) AC Drives
Installation Instructions, publication DRIVES-IN001
Conformal Coating for Variable Speed Drives, publication DRIVES-WP021 Provides information about conformal coating on the Printed Circuit Boards (PCBs), which protects
Control System Packaging for Corrosion Mitigation Design and Installation Guideline,
publication TIRE-RM001.
Control System Packaging for Corrosion Mitigation White Paper,
publication WWW-WP001.
EtherNet/IP Network Devices User Manual, ENET-UM006
Ethernet Reference Manual, ENET-RM002 Describes basic Ethernet concepts, infrastructure components, and infrastructure features.
System Security Design Guidelines Reference Manual, SECURE-RM001
Industrial Components Preventive Maintenance, Enclosures, and Contact
Ratings Specifications, publication IC-TD002
Safety Guidelines for the Application, Installation, and Maintenance of
Solid-state Control, publication SGI-1.1
Safety Products Information, https://ab.rockwellautomation.com/Safety
Industrial Automation Wiring and Grounding Guidelines, publication 1770-4.1
Product Certifications website, rok.auto/certifications. Provides declarations of conformity, certificates, and other certification details.
Provides the basic information needed to properly wire and ground Pulse Width Modulated (PWM) AC
drives.
components with micro lead spacings. Coated PCB is for the protection of the micro lead components
that are vulnerable to dust and moisture build up, which can result in conductive paths.
Provides guidelines for the use of electronics or automation equipment in the tire and rubber industry
with respect to the protection of the product from corrosive gases and contaminants that are present in
the manufacturing environment.
Provides guidelines for the use of Rockwell Automation products in the water/wastewater industry
with respect to attempting to protect the product from corrosive gases that are present in the
manufacturing environment.
Describes how to configure and use EtherNet/IP devices to communicate on the EtherNet/IP
network.
Provides guidance on how to conduct security assessments, implement Rockwell
Automation products in a secure system, harden the control system, manage user access,
and dispose of equipment.
Provides a quick reference tool for Allen-Bradley industrial automation controls and
assemblies.
Designed to harmonize with NEMA Standards Publication No. ICS 1.1-1987 and provides
general guidelines for the application, installation, and maintenance of solid-state control in
the form of individual devices or packaged assemblies incorporating solid-state
components.
Provides various products and information related to standards and safety.
Provides general guidelines for installing a Rockwell Automation industrial system.
You can view or download publications at rok.auto/literature
.
Rockwell Automation Publication DRIVES-AT003C-EN-P - October 2020 59
Rockwell Automation Support
Use these resources to access support information.
Technical Support Center Find help with how-to videos, FAQs, chat, user forums, and product notification updates. rok.auto/support
Knowledgebase Access Knowledgebase articles. rok.auto/knowledgebase
Local Technical Support Phone Numbers Locate the telephone number for your country. rok.auto/phonesupport
Literature Library Find installation instructions, manuals, brochures, and technical data publications. rok.auto/literature
Product Compatibility and Download Center
(PCDC)
Download firmware, associated files (such as AOP, EDS, and DTM), and access product
release notes.
rok.auto/pcdc
Documentation Feedback
Your comments help us serve your documentation needs better. If you have any suggestions on how to improve our content, complete the
form at rok.auto/docfeedback
.
Allen-Bradley, expanding human possibility, FactoryTalk, Rockwell Automation are trademarks of Rockwell Automation, Inc.
EtherNet/IP is a trademark of ODVA, Inc.
Trademarks not belonging to Rockwell Automation are property of their respective companies.
Rockwell Automation maintains current product environmental compliance information on its website at rok.auto/pec.
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Publication DRIVES-AT003C-EN-P - October 2020
Supersedes Publication DRIVES-AT003B-EN- P - June 2017 Copyright © 2020 Rockwell Automation, Inc. All rights reserved. Printed in the U.S.A.
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