Q. Adjustable-Speed Drive Systems

1. Properties and Types

Identify properties, types, and applications ^{2, 3, 4}

• How to select a VFD ⁴
• The Basics of Variable-Frequency Drives ²
• The Basics of AC Drives
• Why do we need variable speed drives (VSD)?
• Comparison of motor speed control methods
• Adjustable Speed Drives Tutorial
• AC Adjustable Speed Drive (ASD) – An Overview
• Benefits and Potential Drawbacks of VSDs
• Variable speed drives in pumping applications
• Adjustable speed drive motor protection applications and issues

2. Inspection and Test Procedures

Apply visual and mechanical inspections ^{3, 4}

• NFPA 70 2017: Article 430 Part X Adjustable-Speed Drive Systems ^2 3 4
• Motor Selection for Adjustable-Speed Drives

Employ methods and procedures for electrical tests ^{3, 4}

• NFPA 70B: Chapter 11.22 Adjustable Speed Drive Testing ^2 3 4
• Why do variable speed drives fail and how do we test them?
• Testing Large Adjustable Speed Drive Systems

3. Interpretation of Test Results

Evaluate results of electrical tests ^{3, 4}

• NETA-ATS 2017: Section 17 Adjustable-Speed Drive Systems ^2 3 4
• NETA-MTS 2019: Section 17 Adjustable-Speed Drive Systems ^2 3 4
• Effects of AC Drives on Motor Insulation

Last Update: Aug 21, 2023