BS EN IEC 60034-27-1:2018

What is BS EN IEC 60034-27-1 – Rotating electrical machines about?

BS EN IEC 60034 is a European standard that discusses the off-line partial discharge measurements on the winding insulation for rotating electrical machines.

The measurements methods described in BS EN IEC 60034-27-1 are applicable to the stator windings of machines with or without conductive slot coating and the stator windings of machines made with form wound or random wound windings.

In special cases like high voltage rotor field windings, BS EN IEC 60034-27-1 is applicable as well. The measurement methods are applicable when testing with alternating sinusoidal voltages from 0,1 Hz up to 400 Hz.

Interpretation guidelines are given in BS EN IEC 60034-27-1 and are applicable only if all the following requirements are fulfilled:

• Measurements performed with power frequency of 50 Hz or 60 Hz, or when testing with power supply within a frequency range of 45 Hz to 65 Hz
• Form wound windings and winding components such as bars and coils
• Winding with conductive slot coating. This is usually valid for machines with a voltage rating of 6 kV and higher

The testing procedures for off-line Partial discharge measurements of BS EN IEC 60034-27-1 can be used for assessing the uniform quality of manufacturing or/and the trending of this kind of windings as well as converter driven machine windings.

Who is BS EN IEC 60034-27-1 – Rotating electrical machines for?

BS EN IEC 60034-27-1 on rotating electrical machines applies to:

• Manufacturer of electric motors
• Manufacturer of induction motor
• Quality testing of rotating electrical machines
• Suppliers and distributors of electrical machines
• Electrical engineers

Why should you use BS EN IEC 60034-27-1 – Rotating electrical machines?

Electrical machines are usually rotating devices that create electromagnetic torque due to the magnetic coupling field. The machines that perform electromagnetic conversion of energy is called rotational converters. The rotating electrical machine consists of a stator, rotor and the air gap between them.

Partial discharge measurement made by PD testers, using the surge test as the driver, is the voltage of the PD spikes. This voltage is proportional to the amount of discharge and measured in mV.

BS EN IEC 60034-27-1 provide guidance on the measurement and analysis of partial discharge:

• Presence of ageing effects and potential defects in the insulating system
• Ageing processes
• Further measures and intervals between overhauls

BS EN IEC 60034-27-1 provides you with the limitations on the rotating electrical machines where the recalculation of the measured PD signal to an equivalent charge is an additional step that is dependent on the measurement and the calibration equipment is been used for normalization, as well as the method used. For individual bars and coils, absolute limits for PD magnitude are also difficult to establish due to disparities between different test equipment and test setups. Therefore, no absolute limits are given in the current version of BS EN IEC 60034-27-1.

What’s changed since the last update?

BS EN IEC 60034-27-1:2018 supersedes DD CLC/TS 60034-27:2011, which is withdrawn. It includes:

• In 1st version the scope was not well defined and open to a too wide range of measurement frequencies. That has been corrected.
• In 1st version pulse magnitude was defined in different ways. Now, 2 definitions are given, one for each method.
• In 1st version the types of PD were erroneous. Especially the definition of the most critical “slot discharges” has been improved.
• Adding one more common test arrangement to Clause 7 and Moving part of the original text (valid for old fashioned instruments) to new Annex H.
• Adding Annex A, Annex B, Annex G