IEC 60034-18-32:2010 pdf Rotating electrical machines – Part 18-32: Functional evaluation of insulation systems – Test procedures for form-wound windings – Evaluation by electrical endurance
1 Scope
This part of IEC 60034-1 8 describes test procedures for the evaluation of electrical endurance
of insulation systems for use in a.c. or d.c. rotating electrical machines using form-wound
windings. The test procedures are comparative in nature, such that the performance of a
candidate insulation system is compared to that of a reference insulation system with proven
service experience. The test procedures are principally directed at the insulation systems in
air-cooled machines but may also be used for evaluating parts of the insulation systems in
hydrogen cooled machines. Note that the qualification procedures of inverter duty insulation
systems for form-wound windings can be found in IEC 60034-1 8-42.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60034-1 , Rotating electrical machines – Part 1: Rating and performance
IEC 60034-1 5:2009, Rotating electrical machines – Part 15: Impulse voltage withstand
levels of form-wound stator coils for rotating a.c. machines
IEC 60034-1 8-1 :201 0, Rotating electrical machines – Part 18-1: Functional evaluation of in-
sulation systems – General guidelines
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 mainwall insulation
main electrical insulation that separates the conductors from the earthed stator/rotor core in
motor and generator windings
3.2 turn insulation
electrical insulation that covers each conductor in coils/bars
3.3 interturn insulation
electrical insulation that separates the conductor turns from each other in coils/bars
3.4 corona protection material
material which is used to coat a stator coil/bar within the slot portion of the stator core to
avoid slot discharges
3.5 stress grading material
material generally having a non-linear resistivity characteristic, applied to the endwindings of
stators to reduce the maximum surface electrical stress
4 General considerations
4.1 Relationship to Part 1 of IEC 60034-1 8
The principles of Part 1 of IEC 60034-1 8 should be followed unless the recommendations of
this International Standard indicate otherwise.
4.2 Selection and designation of test procedures
One or more of the procedures in this International Standard should be suitable for the
majority of evaluations. Evaluation is usually performed by the manufacturer of the
machine/coils or by a third party laboratory. It is the manufacturer’s responsibility to justify the
most suitable procedure in Table 1 on the basis of past experience and knowledge of the
insulation systems to be compared.
The test procedure should be selected from Table 1 and designated by IEC 60034-1 8-32
procedure N, where N is the designation given in the Table 1 . Subclauses 4.3, 4.4 and 4.5
give guidance on how to select the test procedure.
All the above tests are carried out at room temperature. However, if they are to be performed
at any other temperature (see 6.2.2), the designation of the test procedure shall include the
Celsius temperature in brackets, e.g. AA(1 90). Each of the procedures may be used for the
full evaluation according to 4.5.1 or for the reduced evaluation according to 4.5.2.
Procedure AA is the preferred choice if the manufacturer has no past experience or
knowledge of the candidate system and the behaviour of the mainwall insulation is defined.
4.3 Reference insulation system
A reference insulation system should be tested using a test procedure equivalent to that used
for the candidate system (see IEC 60034-1 8-1 ). The reference insulation system should have
service experience at not less than 75 % of the intended maximum rated voltage of the
candidate system. When extrapolation of the insulation thickness is used, some information
should be provided showing the correlation between electrical lifetime and electrical stress for
the different insulation thicknesses.
IEC 60034-18-32:2010 pdf Rotating electrical machines – Part 18-32: Functional evaluation of insulation systems – Test procedures for form-wound windings – Evaluation by electrical endurance
