Subject 347A

Bulletin Dated: January 20, 2017

SUMMARY OF TOPICS

The following changes in requirements to the Standard for Medium Voltage Power Conversion Equipment, UL 347A, are being proposed:

1. Editorial Correction to Table 19.1

2. Addition of Section 19.6 Covering Circuits Provided with Solid Insulation

3. Replacing References to UL 347B with References to UL 347

4. Clarification of Short Circuit Test Requirements for Bypass Circuits

5. Addition of Series Connected Component Spacings for 600 V and Below

6. Clarification of Scope to Reference UL 347 for Solid State Reduced Voltage Starters

7. Capacitor Discharge Test in UL 347A

8. Clarification of Clause 14.1 - Interlocking Requirments

9. Editorial Revision to Clause 15.1

10. Revision to Clause 15.4

11. Editorial Revision to Clause 19.3.2.1

12. Revision to Clauses 19.4.1 & 19.5.1, Changing Reference to UL 61800-5-1

13. Revisions to Impulse Testing when No Isolating Means is Provided

14. Revisions to Operation Tests

15. Editorial Revisions to Table 19.3

16. Breakdown of Components Test - Clarification of Test Method