Test of non-separable thin sheet material 9 V+ H: u5 ?/ V/ x! `- o3 x+ H
2.10.5.2 ^9 q! \% G9 E. W; ~' ?+ Z
60950(ed.3) 4 m) g3 S. D% F" E8 S
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Question: ) j' i6 B( @( Y( K1 yHow is non-separable thin sheet insulation in wound components tested? 7 g6 }+ E6 G9 ~+ k2 ERationale:3 s8 X8 o$ G9 P: _" i1 V5 C; i
There are non-separable thin sheet foils on the market and used in wound components,- [, z3 f- [3 H8 a& Y$ V: e0 q
which cannot be tested according to the requirements and test-method in the existing G- D# `! {: b
standard. A proposal was made to TC74-WG6 how this matter can be handled. The0 N0 o* q; [$ U
proposal is attached. ' h# W$ D" S4 o0 K" k" d5 i1 ]" v _Decision: 3 d5 E; G. a, ~Use of non-separable thin sheet insulation in wound components 8 }- K7 w: I$ t7 u6 rThe following proposal shall be used until the new edition is published. 9 T* _4 m( p1 q) S3 Y* c7 ` w0 Q4 X1. Introduction 6 J+ u) J0 j. L5 [This document presents two alternative versions of the test procedure given in IEC . q' c! R# l/ ?# b, \61558-1 for checking the mechanical durability of thin sheet materials. 7 j9 p* b- x- ], O4 k6 kTest method X adapts the published procedure to the conventions and practices used in4 J3 o5 l, L/ L& j5 @9 w
IEC 60950. In Method X, the metal foil is secured to the sample prior to the test.6 B6 W) A3 S" a: d% j4 t
Test method Y is the slightly different procedure observed on a video presentation,* P( Z0 N( a" ~( Q0 \* n9 w
whereby the metal foil is only added to the test assembly after the sample has been - b+ P5 r; Z- t% n! ~7 tstressed by rotating it in the test fixture.1 n1 z& m' r% Q" w% a
Test method Y appears to be the more practical method, and is evidently how the test is4 }" Y. K0 f) ^- V: q0 o0 Y
carried out in at least one test laboratory. The two methods should give the same results.* ]# ^9 ?: u- c- H
2. Proposal 2 m& Z" T3 o \: R: z' |8 {Change the title of 2.10.5.2 to the following:- ?' t& C6 x2 U2 v" Z$ |) y4 b: |
2.10.5.2 Separable thin-sheet material7 H/ N. x! z. \* x
Modify the first paragraph of 2.10.5.2 as follows: % a7 |0 b; ]3 [Insulation in separable thin sheet materials, and in two layers of non-separable thin sheet 9 g. ^8 [& R0 U: {materials, is permitted, …. 1 I( o' \' H) o) j) LAdd a new sub-clause 2.10.5.X or 2.10.5.Y. & J( ~# B- V$ C; WTest Method X / Y d- Z( V: Y2.10.5.X Non-separable thin sheet material) `# I( Y t' B. m
Insulation in three or more layers of non-separable thin-sheet materials is permitted for use within7 K& r# g8 C( G9 C" j) s
the equipment ENCLOSURE, and shall not be subject to handling or abrasion during servicing. It " S0 n3 ?: V; g( R9 R2 oshall have adequate mechanical strength.7 f* c( e8 {: Q6 q1 f
NOTE - The purpose of the tests in 2.10.5.X is to reveal defects that are hidden in inner layers of insulation,# {0 i9 s: z& q* g$ R% b
so there is no test for insulation in two layers. For insulation in two layers of non-separable thin-sheet 3 l2 V. u8 @$ pmaterials, see 2.10.5.2* {' U9 J% }( v8 N8 Y
There is no requirement regarding distances through insulation, nor for all layers of insulation to be 4 B- u, u' s: j$ T' Y+ C7 yof the same material.+ F* G7 {/ ^6 q6 e+ q
Compliance is checked by inspection and by the following test:" R2 s9 h6 I" T& ~1 w, e0 U9 w
Three test samples of thin sheet material are used, each approximately 70 mm wide.+ I, T5 X7 f% K7 Y% N- s/ t
One sample is fixed to the mandrel of the test fixture as shown in figure 5X. 0 i& l/ E5 u" M9 x! ?* OA sheet of aluminium or copper foil, 0,035 mm ± 0,005 mm thick, approximately 30 mm wide and at& o- v5 E! x4 E; m/ J. Y4 P* j7 s1 Q, i
least 100 mm long, is fixed to the surface of the sample. The foil is positioned so that its edges are$ e6 l8 ], \. v$ g2 I' \" j
approximately 20 mm from the edges of the sample (see figure 5Xd) and so that when the 5 Q* j& t5 \9 ]+ smandrel is in its final position, the foil overlaps the free end of the sample by at least 10 mm (see6 ]5 g* U1 q& H0 B6 _3 Z2 j8 t
figure 5Xc). The foil is tightened by a pull of approximately 1 N, using an appropriate clamping6 m" c1 O3 z' @- h2 a
device. : Z8 ]) E6 }* y$ b2 P! X: ^A pull of 150 N is applied to the free end of the sample, using an appropriate clamping device. The ' }$ J( t1 `* o4 v; `mandrel is twice rotated forwards and backwards by 230°, and then forwards to the final position.; {6 g* B# _( L; [1 K+ A
While the mandrel is in its final position, and within the 60 s following the final positioning, an2 Y- m& [4 Y4 \1 b
electric strength test is applied between the mandrel and the metal foil in accordance with 5.2.2,- t5 E( ^6 v8 ]5 @! E
using a test voltage of 1,5 times the value specified in table 5B. ! @' s7 e- A: E# D9 P. CThe test is repeated with the other two samples' y) k6 c7 X' @+ _; X6 x; P
If a sample breaks at the clamping device during rotation, the test is repeated on a fresh sample. If " y+ I9 Y9 h. e% A- bone or more samples breaks at any other place, the test has failed. 8 u# E7 r8 v. Q1 u/ B4 V5 N+ d0 O............................ 2 [# n G5 i7 S8 @Add new Figure 5X (adapted from Figure 6 of IEC 61558-1)8 c i, Z2 N4 o; {" y U
Figure 5Xa is as figure 6a of IEC 61558-1, modified as follows:) n6 A4 W' y. Y
Replace "3 x R = 0,5 ± 0,02" by "R = 0,5 ± 0,02 (typ)" # T5 I d& u8 qReplace "Material: steel nickel plated or brass" by "Material: metal"& W' P \0 ~: I5 k, g) g6 i$ R
Figure 5Xd is the same as figure 6c of IEC 61558-1 , a7 K# N* A' e' w6 c$ p8 l% _Test Method Y 4 f8 C0 u: M" b7 K0 M1 _2.10.5.Y Non-separable thin sheet material6 _- t: t6 E0 C( p
Insulation in three or more layers of non-separable thin-sheet materials is permitted for use within) M+ ^& G' H+ `# F1 k3 v
the equipment ENCLOSURE, and shall not be subject to handling or abrasion during servicing. It1 U, R% R; @7 e2 `- C' O
shall have adequate mechanical strength., S- j6 [4 s! E! o& [0 @
NOTE - The purpose of the tests in 2.10.5.y is to reveal defects that are hidden in inner layers of insulation,$ Q7 C' k1 `0 c+ d3 N1 c# P3 j
so there is no test for insulation in two layers. For insulation in two layers of non-separable thin-sheet % L2 z4 f$ K; V3 J$ U0 |7 `1 W0 Umaterials, see 2.10.5.27 N0 N* c$ c8 o& U& I
There is no requirement regarding distances through insulation, nor for all layers of insulation to be* h9 Z7 [( I9 n1 w8 ]7 }- ~
of the same material.& ^# C6 C/ ?& n
Compliance is checked by inspection and by the following test: 8 u2 o( C2 r aThree test samples of thin sheet material are used, each approximately 70 mm wide. 4 _" d% Q8 u$ U' rOne sample is fixed to the mandrel of the test fixture as shown in figure 5Y.& h7 ^/ @. Q5 u9 P# X9 N
A pull of 150 N is applied to the free end of the sample, using an appropriate clamping device. The7 ^* m7 ?8 P5 B
mandrel is twice rotated forwards and backwards by 230°, and then forwards to the final position. 6 T$ D# O% U/ F6 k& CA sheet of aluminium or copper foil, 0,035 mm ± 0,005 mm thick, approximately 30 mm wide and at2 W& s! p* J$ l8 ?- P+ _8 e* ?
least 200 mm long, is placed across is the surface of the sample, hanging down on each side of- n4 y/ f* b" d) g8 U- n# ?
the mandrel. The foil is tightened by a pull of approximately 1 N at each end, using appropriate 4 H4 l3 d) g, D# Aclamping devices.. The foil is positioned so that its edges are approximately 20 mm from the edges' Z$ y4 O& }2 ~0 a9 L8 U
of the sample (see figure 5Yd).2 p& f7 F3 Q( y. z2 z, Y% ?4 N
While the mandrel is in its final position, and within the 60 s following the final positioning, an/ V2 s4 R. Z9 o1 e% \8 L. z. f
electric strength test is applied between the mandrel and the metal foil in accordance with 5.2.2,- m; p) h- y, R. q9 \
using a test voltage of 1,5 times the value specified in table 5B. ; F- B) W% N9 S1 ^) p" p% h' ]7 e' u- yThe test is repeated with the other two samples ( n( N* Q& ^- S# a2 xIf a sample breaks at the clamping device during rotation, the test is repeated on a fresh sample. If9 d- ~" U# s. @5 N9 R X0 g
one or more samples breaks at any other place, the test has failed.1 Z) m P5 P: \7 i2 T% t2 n
............................... ; h- W" J* ?0 P; L" V/ y5 L& uAdd new Figure 5Y (adapted from Figure 6 of IEC 61558-1) ; Q; r4 J( W1 l8 l! s! xFigure 5Ya is as figure 6a of IEC 61558-1, modified as follows: 4 u y2 [- G) q' B* N) A1 GReplace "3xR = 0,5 ± 0,02" by "R = 0,5 ± 0,02 (typ)"" J" D6 [- V) o8 N5 m
Replace "Material : steel nickel plated or brass" by "Material: metal" - J, M3 }" y0 ~4 v2 K$ DFigure 5Yd is the same as figure 6c of IEC 61558-1! U$ s4 n# e( v3 v
DSH 392