36B-MT10(Washington)42 2004-12-09

INTERNATIONAL ELECTROTECHNICAL COMMISSION TECHNICAL COMMITTEE N°: 36 INSULATORS SUB-COMMITTEE 36B: INSULATORS FOR OVERHEAD LINES MAINTENANCE TEAM 10 Meeting in Washington 9th December 2004 Project 36B 61109 Ed2 Actions for 36BMT10 arising from the discussion of 36B/233/CD by SC 36B

The compiled comments received on 36B/233/CD were studied by SC 36B . The following document shows the actions to be undertaken by MT10. Actions shown in YELLOW Responsibilities in RED

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Comment N° Clause/ Paragraph & National Subclause Figure/ Table Committee

0 CZ 0 DE 0 ES 0 UK 0 US 1 CN

Type of comment

General General General General

MT10 Comments We agree with the Secretary 2 Title Paragraph IRL page 1

MT10 Comments We agree with the Secretary

COMMENTS

Date

Document

2004-12-09

36B/233/CD

Proposed change

OBSERVATIONS OF THE SECRETARIAT on each comment submitted

(Gen./Tech./Edit.)

General

The title

36B-MT10(Washington)42

General

Ed

The Czech NC support the draft with (no?) comments The German NC agrees with this document without any comments The Spanish National Committee accepts the draft as such without comments The UK National committee accepts the proposal without comment The US National Committee has no comments to offer on this document at this time

“Suspension and tension” can not cover all possible stress on insulators in service. Therefore the name of insulator should be the same as ceramic one.

Composite long rod insulators for a.c. overhead lines with a nominal voltage greater than 1000V.

36B Meeting discussion & decision CN proposal refused Replace the “d” in “definitions” with a “IEC 61109/Ed2: Composite suspension and tension insulators for a.c. overhead capital “D” lines with a nominal voltage greater than 1 000 V. Definitions, test methods and acceptance criteria” CONV 36B Meeting discussion & decision Accepted

Not acceptable “Suspension and tension” was used to differentiate these insulators from post and line post insulators – it is not intended to define the mechanical stress (which is tensile). The definition of a long rod insulator in the IEV could include these latter types: “insulator comprising an insulating part having an approximately cylindrical core, with or without sheds, and external or internal fixing devices attached to each end”

Correct

-3Comment N° Clause/ Paragraph & National Subclause Figure/ Table Committee

3 IT

General

Type of comment

COMMENTS

36B-MT10(Washington)42 Proposed change

OBSERVATIONS OF THE SECRETARIAT on each comment submitted

(Gen./Tech./Edit.)

Technical

In comparison to the old document it misses the annex D judged very useful from the practical point of view

Introduce the same annex D of the actual To be discussed edition of the IEC 61109 Annex D gives a summary of all the tests and the main stresses and values used.

MT10 Comments 36B Meeting discussion & decision Not acceptable: IT comment not accepted We feel that Tables 1 & 2 already give a sufficiently detailed summary. Acceptable 4 Introductio G There is a proposed text in 36C/150/CD Add the following paragraph to the introduction: FR n which usefully explains the use of the 1000h test for both a.c. and d.c. "The practical use of composite insulators covers both a.c. and d.c. applications. In insulators. We suggest reproducing it spite of this fact a specific tracking and here too erosion test procedure for d.c. applications as a design test has not yet been defined and accepted. The 1 000 h a.c. tracking and erosion test of IEC 62217 is used to establish a minimum requirement for the tracking resistance of the housing material." MT10 Comments We agree with the Secretary (but use version from 61952)

5 NL

Introduction

3rd paragraph

MT10 Comments We agree with the Secretary

Technical

36B Meeting discussion & decision Accepted DE suggests updating the information on brittle fracture, agreed. Jens Seifert to supply to MT10. JS & CDT The 3rd paragraph deals with power arc Delete this paragraph. Not acceptable tests. Such a test "subject to purchaser Experience has shown that optional tests and user" should not just be mentioned that are included in the list of applicable in an introduction, as the user of this tests are very often imposed as document may overlook this. It has to be mandatory. Power arc tests are intended listed among the other tests in the to test equipment (not only the insulator, standard. This is information about but also conductors and fittings) in possible tests and should be available conditions that reproduce the electrical for the user of the standard. Therefore, and mechanical environment of a given include a power arc test, subject to system (Current, duration, supply and agreement between purchaser and return circuit geometry etc.). It is not manufacturer, as a design test in possible to define a generic test which subclause 8.1 and clause 9. could be used as a design test for all insulators, fittings and conditions. 36B Meeting discussion & decision Support the Secretary’s opinion, not accepted

-4Comment N° Clause/ Paragraph & National Subclause Figure/ Table Committee

6 CN

4

Type of comment

COMMENTS

36B-MT10(Washington)42 Proposed change

(Gen./Tech./Edit.)

EML is used and explained only in annex To delete EML and its explaining. CONV A. It is not necessary to appear in this clause. MT10 Comments 36B Meeting discussion & decision We agree with the Secretary Accepted 7 Clause 4 Paragraph Te/Ed Pultruded rod is not fibre reinforced “RBGF Resin bonded glass fibre” IRL 1 plastic. It is resin bonded glass fibre (RBGF). The glass in the core is continuous. The term fibre reinforced plastic (FRP) is associated with chopped glass strands in plastic. MT10 Comments 36B Meeting discussion & decision We agree with the Secretary, however it would be simpler to remove the abbreviation MT10 proposal accepted completely from Annex A CONV 5 Note Technical About the identification exist the IEC Harmonize the clause to the IEC guide 8 guide 111 that give all the information IT

Editorial

MT10 Comments We agree with the Secretary

9 IT

7

1

MT10 Comments We agree with the Secretary

OBSERVATIONS OF THE SECRETARIAT on each comment submitted

Technical

Correct, Annex A is not normative and the EML is defined there.

Correct However FRP is only used in Annex A, so it is proposed to remove the abbreviation from 4 and to replace FRP by RBGF in Annex A.

Not acceptable Guide 111 gives information specific to sub-station equipment and is not totally compatible with line insulators. IEC 62217 is the reference for this clause, any changes should be made there; however the relevant points from guide 111 have already been adopted word for word wherever possible

36B Meeting discussion & decision Not accepted. However will include statement in the introduction saying that guide 111 has been followed wherever possible. CONV About the Transport, storage and Harmonize the clause to the IEC guide Not acceptable installation exist the IEC guide 111 that Guide 111 admits “It is impossible here give all the information to cover in detail the complete rules…” and then just gives some points for consideration with no specific details. The CIGRE 184 referenced in IEC 62217 is much more complete. 36B Meeting discussion & decision See comment 8 IT

-5Comment N° Clause/ Paragraph & National Subclause Figure/ Table Committee

10 IRL

Clause 9

Paragraph 2

Type of comment

COMMENTS

36B-MT10(Washington)42 Proposed change

OBSERVATIONS OF THE SECRETARIAT on each comment submitted

(Gen./Tech./Edit.)

Te

Do not understand meaning of this paragraph Please clarify

No proposed change can be given as the meaning of the paragraph is not understood.

MT10 Comments 36B Meeting discussion & decision We agree with the Secretary, this “standard” clause does not need to be changed. MT10 comment agreed 11 Clause Paragraph Te/Ed The term “same design” with respect to “Same material of the fittings, the same IRL 10.1 3, item b) the end fitting design should be connection zone design, and the same clarified. method of attachment;” 36B Meeting discussion & decision MT10 Comments Acceptable – suggest making the same change in 61952 MT10 proposal accepted

“Same material of the fittings, the same connection zone design, and the same housing-to-fitting interface geometry;” CONV

To be discussed The paragraph says: “Measure the creepage distance using the dimensions and tolerances on the drawing, not those given in the client’s specification. If the client specifies a minimum creepage distance, then the negative tolerance cannot go below this value.

Acceptable Perhaps also add housing to fitting interface geometry ?

-6Comment N° Clause/ Paragraph & National Subclause Figure/ Table Committee

12 FR

10.1

Table 1

Type of comment

COMMENTS

36B-MT10(Washington)42 Proposed change

OBSERVATIONS OF THE SECRETARIAT on each comment submitted

(Gen./Tech./Edit.)

T

The strength of the assembled core can Add crosses accordingly. be influenced by housing manufacturing parameters (e.g. temperature, pressure or chemicals). Therefore, the assembled core load tests should be extended to lines 1, 7, 8 and 11.

This suggestion is debatable. Line 1 (Housing materials) will not have any influence if the assembly process and parameters are the same. Line 7 (Housing manufacturing process) will have no influence in the case of slipon” housings. Line 8 (Housing Assembly process) can have an influence for directly injected housings, but in the case of “slip-on” sheds or housings there will be no influence. Line 11 (Core/housing/end fitting interface design) may only have an influence if the geometry of the opening of the end fitting is changed. In this case it is covered by line 10 (connexion zone design) since the opening is, by definition, part of the end fitting where the loads are transferred from body to fitting. Suggest adding a line 12 for “Temperatures, pressures seen by the assembled core during manufacture

MT10 Comments We prefer to add the crosses as proposed by France. CONV Additionally these crosses should have a note as follows: NOTE – Not necessary if it can be demonstrated that the change has no influence on the assembled core strength CONV

36B Meeting discussion & decision FR MT10 proposal is acceptable; USA different batches of material may have slightly different cure temperatures. What is the limit on temperatures ? Principle accepted, referred to MT10 for technical details. CA Do not make it too complicated.

13 10.1 Table 1 NL MT10 Comments We agree with the Secretary

Add a power arc test as design test as subclause 11.4. 36B Meeting discussion & decision Not accepted

Technical

A power arc test is missing.

Not acceptable See comment 5 NL

-7Comment N° Clause/ Paragraph & National Subclause Figure/ Table Committee

14 PL

10.1

Type of comment

COMMENTS

36B-MT10(Washington)42 Proposed change

OBSERVATIONS OF THE SECRETARIAT on each comment submitted

(Gen./Tech./Edit.)

Technical

We propose to widen the scope of the To be discussed design tests by including an additional Research carried out in the past in test – the mechanical fatigue test, which Canada brought to light an influence of could be performed either on completely vibrations on the long-term strength of mounted composite insulator or on core composite insulators. However those equipped with metal fittings. affected used a rudimentary assembly Reason: method which is no longer used. It is not In service, insulators are subjected to proven that this influence exists with action both of static loads and dynamic current technology. loads caused mainly by Aeolian vibrations. These alternating loads have significant influence on durability of composite insulators, what was confirmed by tests. MT10 Comments 36B Meeting discussion & decision We agree with the Secretary PL proposal not accepted Additionally if dynamic loads do not exceed the damage limit, there is no risk of reduced durability. We have no knowledge of service failures attributed to dynamic loads. (see annex C) 15 10.1 Table 1 Technical Some insulator designs introduce It is suggested to make a footnote at row Acceptable SE spacers (to fix the core in a central 8, “Housing assembly process”, which If this is adopted, the test should also be position in the housing) or joining rings states that such design features shall be valid for insulators without spacers/joints. (to seal separately made sections of the present also on shorter test objects housing), for longer insulators during the (which normally not need a spacer or manufacturing process. Such new joining ring) when tested in tracking and features of the design may be a weak erosion test, to make the design test valid point of the whole design (see CIGRE also for the longer insulator types of the Report 33-402, 2002). same design. 36B Meeting discussion & decision MT10 Comments USA In some cases it is impossible to make a short sample with fully representative We agree with the Secretary joints/spacers. This should figure in the definition of the samples both for the tests on interfaces and for the tracking and erosion tests. Principle accepted, MT10 to discuss details of USA comment CONV Add provision for slightly longer creepage than 800 when with spacer/joints are tested. 16 11 Table 2 E References to 10.1… incorrect Align accordingly. Correct FR

-8Comment N° Clause/ Paragraph & National Subclause Figure/ Table Committee

16 IRL

Clause 11

Table 2

16 11 Table 2 IT 16 11 Table 2 SE MT10 Comments We agree with the Secretary 17 11.1.2 SE

Type of comment

36B-MT10(Washington)42

COMMENTS

Proposed change

(Gen./Tech./Edit.)

Ed

Editorial Editorial

Technical

Reference to clauses 10.1.1 and 10.2 is Replace Correct, acceptable incorrect. Clause does not exist and/or “pre-stressing – see 10.1.1 and 10.2. for does not refer to product specific preproduct specific pre-stressing” stressing tests. With Since the specific product standard test “Sudden load release test pre-stressing “Assembled core load time test” is listed “Thermal-mechanical test pre-stressing“ by name in Table 2, the specific product CONV standard pre-stressing tests “Sudden load release test” and “Thermalmechanical test” should also be named in Table 2 In the table all the items make To change 10 in 11 Correct references to the clause 10 instead of 11 All references to clause 10 shall be to 10.1.1, 10.2, 10.1.2, 10.1.3 shall be Correct clause 11. 11.1.1, 11.2, 11.1.2 and 11.1.3. CONV 36B Meeting discussion & decision Accepted The same information regarding spacer Suggestion to add: Acceptable if 15 SE is adopted or joining rings as suggested for clause “Spacers or joining rings, if used, shall be 10.1, table 1, above, should also here be present in tracking and erosion test, also included. on short test objects to make the design test valid also for longer insulator types of the same design.” 36B Meeting discussion & decision See 15SE Transfer to 61952 CDT

MT10 Comments We agree with the Secretary Should also figure in 11.1.1 Propose: “If spacers, joining rings or other features are used in the insulator design (notably for longer insulators), the sample shall include any such devices in a typical position.” CONV 18 11.2.2 Technical Environmental conditions with very low SE temperature should be accounted.

MT10 Comments We agree with the Secretary

OBSERVATIONS OF THE SECRETARIAT on each comment submitted

Add a second note: “In certain applications a lower temperature than –35 deg C may be selected by agreement.”

36B Meeting discussion & decision Not accepted

Not acceptable The aim of this test is to apply a specific stress due to temperature change (> 85 K), not to reproduce climatic effects.

-9Comment N° Clause/ Paragraph & National Subclause Figure/ Table Committee

19 IRL

Clause 11.1.3

Paragraph 1

Type of comment

36B-MT10(Washington)42

COMMENTS

Proposed change

OBSERVATIONS OF THE SECRETARIAT on each comment submitted

It is understood that the test is designed to evaluate the core and that IEC 61109, 5.1 is used to assess (amongst other properties) the interface between the housing and the core. However, from experience, IEC 61109, 5.4 has also been found to be a useful to give some initial indication of the quality of bond of the housing to the core. Can examples of insulator constructions be provided (in which the housing is not bonded to the core) where it is necessary to remove the housing from the core? Why it is necessary to remove housing

No proposed change can be given until the technical basis of the 2nd sentence in the paragraph is better understood.

This requirement is for insulators where the sheds (or whole housing sections) are slid onto the core using a grease to fill voids. When a section is cut from such an insulator, the grease can migrate onto the cut surfaces and affect the test result of the dye penetration test. Similarly in the water diffusion test the grease passes into the boiling water and pollutes the samples and the equipment.

(Gen./Tech./Edit.)

Ge/Te

MT10 Comments We agree with the Secretary Propose to improve :

36B Meeting discussion & decision Modified MT10 proposal accepted

“However if the housing material is not bonded to the core, then it shall be removed and the remaining core thoroughly cleaned to remove any traces of sealing material before cutting and testing.” CONV 20 11.2 AU MT10 Comments We agree with the Secretary

Editorial

Symbols are mixed in references to temperature

Refer to temperatures in the format 35 °C ± 5 °C. CONV 36B Meeting discussion & decision Accepted

Correct

- 10 Comment N° Clause/ Paragraph & National Subclause Figure/ Table Committee

21 IRL

Clause 11.2.2

Paragraph 4

Type of comment

36B-MT10(Washington)42

COMMENTS

Proposed change

OBSERVATIONS OF THE SECRETARIAT on each comment submitted

(Gen./Tech./Edit.)

Ed

Move paragraph 4 (“Before commencing …”) to the start of the clause to make the paragraph read in the order as the test procedures are performed.

Before commencing the test, the specimens will be loaded at the ambient temperature by at least 5 % of the SML for 1 min, during which the length of the specimens will be measured to an accuracy of 0,5 mm. This length will be considered to be the reference length.

Acceptable

The specimens are then submitted to temperature cycles under a continuous mechanical load as described in figure 1, the 24 h temperature cycle being repeated four times. Each 24 h cycle has two temperature levels with a duration of at least 8 h, one at + 50 °C ± 5 K, the other at – 35 °C ± 5 K. The cold period shall be at a temperature at least 85 K below the value actually applied in the hot period. The pre-stressing can be conducted in air or any other suitable medium.

MT10 Comments We agree with the Secretary 22 Clause Paragraph IRL 11.3.1 1

MT10 Comments We agree with the Secretary

Ed

The applied mechanical load …………… CONV 36B Meeting discussion & decision Accepted Revising wording of paragraph for Both end fittings shall have the same easier readability. connection zone as used on production line insulators, but beyond the end of the connection zone they may be modified in order to avoid failure of the couplings.

36B Meeting discussion & decision Sec proposal accepted

Acceptable However it is important that the material, surface finish etc. of the fittings be the same. It would be better to say: “Both end fittings shall be identical in all aspects to those used on production line insulators, except that they may be modified beyond the end of the connection zone in order to avoid failure of the couplings.” CONV

- 11 Comment N° Clause/ Paragraph & National Subclause Figure/ Table Committee

23 NL

11.4

MT10 Comments We agree with the Secretary 24 12 First FR paragraph Second sentence

MT10 Comments We agree with the Secretary 25 12.2.1 1st JP paragraph MT10 Comments We agree with the Secretary 26 13.3 1st JP paragraph

Type of comment

COMMENTS

36B-MT10(Washington)42 Proposed change

OBSERVATIONS OF THE SECRETARIAT on each comment submitted

(Gen./Tech./Edit.)

Technical

E

Editorial

A power arc test is missing.

Add: 11.4 Power arc test Subject to agreement between purchaser and manufacturer a power arc test shall be applied as per IEC 61467. 36B Meeting discussion & decision See 5NL “arcing devices” may just be for field The electrical type tests shall be performed only once on insulators control satisfying the above criteria for one type and shall be performed with arcing or field control devices, if they are an integral part of the insulator type. CONV 36B Meeting discussion & decision Accepted Mechanical routine test is specified in To replace “14.3” to “14.1” CONV

Not acceptable See comment 5 NL

Acceptable

Correct

clause 14.1, not 14.3.

36B Meeting discussion & decision Accepted Technical Test procedure and criteria should be To revise as follows: “… including if applicable verification of specified for verification of locking system. the locking system in accordance with clause 22 of IEC 60383-1.” CONV MT10 Comments 36B Meeting discussion & decision We agree with the Secretary Accepted In order to obtain more information from 27 Clause Section b), Ge The text indicates that the mechanical the test, unless special reasons apply IRL 13.4 paragraph tensile load applied to the test samples may be increased until the tensile (for instance the maximum tensile load 3 failing load is obtained (provided it is of the test machine), the load should be within the capability of test machine). increased until the failing load is In the event that samples are only reached, and its value recorded. tested up to 100% of the SML (or greater) but cannot be loaded to failure, In the event that the ultimate failure load it should be clearly stated that the of the samples is not obtained (for samples must then be discarded or specific reasons). The test samples destroyed. should be discarded after the test. This would rule out the possibility of the test samples being put back into the manufacturing lot after testing. MT10 Comments 36B Meeting discussion & decision We agree with the Secretary, the mention in clause 13.1 is sufficient. Not necessary

Acceptable

Not necessary Clause 13.1 already specifies that only E2 samples having undergone the magnetic method for galvanizing can be used in service (sentence after table 4). Perhaps it would be better to reinforce this statement ?

- 12 Comment N° Clause/ Paragraph & National Subclause Figure/ Table Committee

28 IRL

Clause 13.5

Paragraph 1

MT10 Comments We agree with the Secretary 29 14.1 1st JP paragraph

Type of comment

COMMENTS

FORM COMMENTS (IEC) 2001-07-01

Proposed change

OBSERVATIONS OF THE SECRETARIAT on each comment submitted

(Gen./Tech./Edit.)

Ed

Technical

Use of words needs revising to make the statement clearer. Missing the word “size” in the sentence.

If only one insulator or end fitting fails to comply with the sampling tests, retesting shall be performed using a new sample size equal to twice the quantity originally submitted to the tests. CONV 36B Meeting discussion & decision Accepted Present 61109 specifies, “Every insulator To delete “+10%” and add the following: shall withstand at ambient temperature a tensile load at RTL corresponding to at “Maximum tensile load should be lower least 50% of the SML for at least 10s” than yield point of end fitting. “ for mechanical routine test. On the other hand, 36B/223/CD specifies, “… a tensile load at RTL corresponding to 0.5XSML (+10%, -0%) for at least 10s.”.

MT10 Comments We agree with the Secretary

36B-MT10(Washington)42

Acceptable

Not acceptable There are cases where customers mistakenly request a routine test at up to 80% of the SML, arguing that it is in conformity with IEC 61109 since it is “at least 50%”. If a diversity of RTL is allowed it would be impossible for the manufacturers to maintain a stock of “standard” insulators – it would be necessary to carry out the RTL test before each delivery rather than during the production process. If a higher RTL is required, this can accommodated by a specific agreement between client and manufacturer.

The upper limit of the test load for mechanical routine test should not be specified. A tensile load which is higher than 0.55XSML (= 0.5XSML +10%) is still effective to eliminate manufacturing defects as mechanical routine test, if a tensile load is lower than yield point of end fitting to prevent end fitting deformation. 36B Meeting discussion & decision JP Request was for economic reasons to cover certain demands from clients. DE Only the manufacturer knows the permissible maximum RTL with respect to the damage limit.. Not accepted