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PD IEC TS 60034 — Rotating Electrical Machines Technical Specification and Efficiency Class Series
Rotating Electrical Machines — Technical Specifications (UK adoption of IEC TS 60034)
📐 PD IEC TS 60034 is a series of Published Documents issued by the British Standards Institution (BSI) in the form of Technical Specifications (TS), corresponding to IEC/TS 60034 and complementing the BS EN 60034 / IEC 60034 rotating electrical machinery family. Addressing the needs of modern variable-speed drive and condition-monitoring practice, the series specifies methods for determining losses and efficiency of converter-fed AC induction motors, on-line partial discharge measurement on stator winding insulation, efficiency classes (IE-code) for variable speed AC motors, and related additional requirements. For engineers in motor design, manufacture, selection, energy-efficiency assessment and insulation diagnostics, this series is a key bridge between the general rotating-machine standard and engineering practice.
💡 Converter-fed motors see currents and voltages rich in harmonics, causing additional losses and higher voltage stress on winding insulation. This series exists precisely to evaluate the efficiency, energy class and insulation condition of such machines accurately.
1. Series Overview 📌
The IEC/TS 60034 series was prepared within IEC Technical Committee TC 2 (Rotating machinery); UK participation was entrusted to Technical Committee PEL/2 (Rotating electrical machinery). A Technical Specification (TS) sits between a full standard and a publicly available specification, typically used where technical content still requires validation. The parts address performance testing of converter-fed induction motors, on-line partial discharge measurement of insulation, and efficiency classification of variable speed motors, filling gaps in the general rotating-machine standard for inverter-fed duty and condition monitoring.
⚠️ This series is a Technical Specification; its content is relatively new and may change when IEC full standards are issued. For mandatory efficiency, testing and certification requirements, refer to the formal standards and applicable regulations.
2. Structure and Technical Highlights 🧩
The series mainly comprises the following parts, summarised by number, topic and core content.
| Standard | Topic | Core content |
|---|---|---|
| PD IEC/TS 60034-2-3:2013 | Specific test methods for determining losses and efficiency of converter-fed AC induction motors | Instrumentation and power analyser requirements, converter set-up (test converter up to 1 kV and final-application converter), loss segregation and efficiency calculation |
| PD IEC/TS 60034-27-2:2012 | On-line partial discharge measurements on the stator winding insulation of rotating electrical machines | Basics of PD, types of PD in rotating machines (internal, slot, end-winding, conductive particles), arcing and sparking, noise and disturbance suppression |
| PD IEC/TS 60034-30-2:2016 | Efficiency classes of variable speed AC motors (IE-code) | Efficiency classification, treatment of auxiliary devices, efficiency rating, tolerances, nominal limits for IE1 to IE5 |
| PD IEC/TS 60034-32:2016 | Additional requirements (scanned) | Supplementary technical content for specific applications or measurements |
⚠️ In this batch PD IEC/TS 60034-32 is a scanned version; its content is written from public-domain knowledge. For detailed clauses, refer to the official BSI publication.
3. Key Technical Requirements 🔥
3.1 Losses and efficiency of converter-fed induction motors (Part 2-3)
Under converter supply, motor terminal voltage and current are non-sinusoidal, and losses arise from both fundamental and harmonic components. The part specifies dedicated test methods: bandwidth and accuracy requirements for instruments and power analysers; converter set-up rules (a standard test converter for rated voltages up to 1 kV, or the final-application converter); and the steps for loss segregation and efficiency calculation. Accurate determination of converter-fed motor efficiency underpins energy-efficiency assessment and energy-class classification.
3.2 On-line partial discharge measurement on stator winding insulation (Part 27-2)
Partial discharge (PD) is an important indicator of winding insulation deterioration. The part describes the basics of PD in rotating machines and distinguishes internal, slot, end-winding and conductive-particle discharges, and discusses non-discharge signals such as arcing at broken conductors and vibration sparking. Because on-line measurement is heavily disturbed by grid harmonics and converter switching noise, the standard gives guidance on noise and disturbance suppression, sensor coupling and measurement systems to help identify genuine discharge signals on site.
3.3 Efficiency classes of variable speed AC motors (Part 30-2)
The part defines efficiency classes (IE-code) for variable speed AC motors. It specifies how efficiency classes are determined, how auxiliary devices (e.g. cooling fans) are treated, rated efficiency and tolerances, and gives nominal efficiency limits for IE1, IE2, IE3, IE4 and up to IE5. For converter-driven fans, pumps and compressors, the IE-code provides a unified basis for energy evaluation and motor selection.
✅ Practice note: converter-fed motor efficiency cannot simply be read from a line-frequency efficiency table. Harmonic losses, converter losses and auxiliary power all materially affect overall efficiency, and must be measured by the dedicated test methods and included in IE-class assessment.
4. Engineering Practice 🛠️
- 🔍 Converter-fed motor acceptance: organise efficiency tests per Part 2-3, verify power-analyser bandwidth and converter set-up, and confirm loss segregation results.
- 📊 Insulation diagnostics: run on-line PD measurements on high-voltage converter-fed motors, classify discharge types, and judge insulation degradation from trends to plan maintenance.
- 📐 Energy-efficient selection: compare motor options using the IE-code of Part 30-2, include auxiliary power, and choose the high-efficiency machine.
- 📋 Condition monitoring: integrate PD, vibration and temperature data into a motor health management system for predictive maintenance.
5. FAQ ❓
Q1: Why can’t a converter-fed motor use the line-frequency efficiency table?
A: Converter supply introduces harmonic losses, and the converter itself has losses while auxiliary devices consume power; these must be measured by dedicated test methods and included in efficiency assessment.
A: Converter supply introduces harmonic losses, and the converter itself has losses while auxiliary devices consume power; these must be measured by dedicated test methods and included in efficiency assessment.
Q2: Why is on-line partial discharge measurement difficult?
A: Site interference from grid harmonics, converter switching noise and corona must be distinguished through sensor coupling, noise suppression and signal identification to isolate true discharges.
A: Site interference from grid harmonics, converter switching noise and corona must be distinguished through sensor coupling, noise suppression and signal identification to isolate true discharges.
Q3: Which motors does the IE-code apply to?
A: Part 30-2 targets variable speed AC motors supplied by converters; line-operated motors use the IE1 to IE4 classes of IEC 60034-30-1.
A: Part 30-2 targets variable speed AC motors supplied by converters; line-operated motors use the IE1 to IE4 classes of IEC 60034-30-1.
Q4: What is the difference between slot and end-winding discharge?
A: Slot discharge occurs between the winding and the slot wall (often due to loose slot wedges or damaged corona shielding), while end-winding discharge occurs between end windings and grounded parts; the mechanisms and remedies differ.
A: Slot discharge occurs between the winding and the slot wall (often due to loose slot wedges or damaged corona shielding), while end-winding discharge occurs between end windings and grounded parts; the mechanisms and remedies differ.
Q5: How does this series relate to BS EN 60034?
A: It is a Technical Specification complement within the IEC 60034 family, used alongside the main standard; within the UK the BSI-published PD IEC/TS 60034 version applies.
A: It is a Technical Specification complement within the IEC 60034 family, used alongside the main standard; within the UK the BSI-published PD IEC/TS 60034 version applies.