SCCR Applying High Fault Ratings Component HOTT

1. SCCRApplying High Fault RatingsComponent HOTT

2. Why is SCCR important? • OSHA – law requires that owners provide a safe workplace for there employees • Installation codes require installing a panel within the available fault level available. Ref: NEC70 section 110.11 • End Users are specifying panels with specific SSCR ratings. • Large users with multiple facilities are standardizing on panels with specific SCCR ratings. • End Users are now doing system studies of there facilities (ex. Arc Flash) and now know the level of fault current available. • OEMs, Panel Builders will offer higher rated panels to differentiate themselves from there competitors

3. Industrial Control Panels Requirements • All panels installed must be marked • This is an electrical code requirement NEC 70 ( 2005 or later) • Responsibility of the installer (contractor or owner of the facility) • Marking

4. Evaluating the Panel – How it works • Evaluate the 3 areas of the panel • Feeder Section • Control Circuit • Branch Circuits The lowest rating of any of the following will determine the rating of the whole panel. • Any power component in the Feeder Section • The circuit protection device protecting the control circuit. • The branch circuit rating • Components that do not require evaluation • Power Transformers, Reactors, Current Transformers, Dry-type capacitors, resistors, varistors and volt meters

5. Locating Feeder Circuit Components “Feeder Circuit” “Branch” CPD • Indentify Components in the feeder • Find all of the last branch circuit protection devices. • All components above the branch circuit protection device are feeder components • Include passive components such as bus bars and power distribution blocks.

6. Identifying Branch Circuit Components • Identifying the Branch Circuit • Find all of the last branch circuit protection devices. • All components below each branch circuit protection device are components in the branch circuit. • Include passive components such terminal blocks Branch Circuit Components Branch Circuit protection device

7. Identifying the Control Circuit • Identifying the Control Circuit • The branch circuit protection device is the only component evaluated. • Control Circuits can be tapped from the main supply or stepped down using a control circuit transformer Control Circuit Components Branch Circuit protection device

8. Indentify the 3 areas of a panel

9. Panel Evaluation Method

10. How to evaluate Branch Circuits 65kA 65kA 100kA 5kA 5kA 100kA 10kA • Determine the rating of the power components in the branch • Compare each component to the branch circuit protection device • Label the branch the lowest of the two ratings 5kA 10kA 65kA

11. Applying High Fault Ratings 65kA 70kA 65kA 100kA High Fault Ratings 5kA 5kA 10kA Individual Ratings • High fault Rating • A SCCR rating based on being tested with a specific branch circuit protected device • This is a conditional rating based on optional manufacturer’s testing • An alternative to using individual ratings that limit the overall marking of the panel.

12. How to you find SCCR Product Data Minimum SCCR Rating High Fault Rating Required Branch Circuit Protection Device Product Label or Installation Instructions Example NEMA 509 Starter

13. Tools available to find SCCR ratings? • Combination Motor Controllers • Catalog or UL website for manufacturers who build using discrete components • Product Selection Toolbox • Disconnects, Circuit Breakers 194R, 140U, 140M • Catalog, Product Selection Toolbox • PowerFlex Drives • User Manual, Technical Data Publications 22td • Solid State Motor Controllers 150 • Catalog, SPD software Utility • Power Distribution Blocks 1492-PD • Product Selection Toolbox, Technical Data 1492-TD013_EN_.pdf • Terminal Blocks 1492-J • Product Selection Toolbox, UL File Report

14. How to you find SCCR Product Data • Products with No Ratings get assigned a minimum Ratings or Assigned Values from UL508A SB4 table