GB/T 11024.2-2019Shunt capacitors for a.c. power systems having a rated voltage above 1 000 V -- Part 2: Ageing testing (English PDF)

4.1 Test requirements and overall objectives

The ageing testing is a special test to verify that the ageing degree that is

caused by increasing test voltage at the rising temperatures does not cause

premature breakdown of the dielectric. It is a means to ensure that the base

material is properly selected and that it does not undergo any rapid ageing. This

test should not be considered as a tool to make any accurate assessment of

the dielectric life characteristics. To this end, manufacturers shall pay attention

to various types of research and development activities.

The ageing testing shall be performed as a special test by the manufacturer for

a particular dielectric system, i.e. not for capacitors of each specific rated value.

f) the length of the component (effective aluminum foil width) is allowed to

vary within 50% ~ 400%; the unfolded length of the component (effective

aluminum foil length) is allowed to vary within 30% ~ 300%.

A.2 Test unit design

If the following requirements are met, the test unit is considered to be

comparable to the production unit:

a) components that meet the requirements of A.1 shall be assembled in the

same manner as the production unit; the insulation between the

components shall be the same or thinner; the components shall be

pressed in the same manner; the compression factor shall be within the

manufacturing tolerance.

b) the number of connected test unit components shall be not less than 4, so

that the capacity under rated voltage (50 Hz) is not less than 100 kvar. All

connected components shall be placed next to each other.

Note 1: The connected components can be connected in series and in

parallel in any way to suit the test equipment.

c) the connections outside the test components can be enlarged, so as to

cope with the increase in current that is caused by the parallel connection

of some components.

d) the thickness of the insulation-to-case shall be the same or thicker.

Note 2: This requirement is to ensure that the drying and dipping

conditions are the same as those of the production unit. The

electrical resistance requirements of the insulation-to-case are

tested in accordance with the tests in Chapters 10 and 15 of

GB/T 11024.1-2019.

e) The height deviation of the casing shall be +/-20% compared to the

production unit; the length and width deviation of the casing shall be +/-50%.

Note 3: In order to allow component size changes, the range of the above

casing dimensions is necessary.

The outer casing materials shall be of the same type (metal, polymer, etc.),

but the topcoat can be omitted or can be different.

To accommodate the test voltage and/or test current, the design of the

bushing and the number of bushings can be adjusted.

f) The drying and dipping processes shall be the same as the normal

production process.

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