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| DSH 392
k4 v( `* I$ H! W' k3 o9 o9 u2 u5 P& ^/ K3 S# c+ M3 I C2 Y" q* n/ @
| Test of non-separable thin sheet material
) M' N# q" H( `; R | 2.10.5.2+ {. u; y6 r1 k! c. n
| 60950(ed.3)
3 ]9 L2 {$ I/ ?+ U | 9 N$ x( f$ ?+ ^$ k
Question:
( {0 z2 L0 [$ DHow is non-separable thin sheet insulation in wound components tested?
6 n# ?* }# x3 E& v. ~Rationale:$ \% ]; m" _+ R
There are non-separable thin sheet foils on the market and used in wound components, ]" P4 ?2 [8 ~6 V* w2 {
which cannot be tested according to the requirements and test-method in the existing0 L6 }0 g; J. O }7 c
standard. A proposal was made to TC74-WG6 how this matter can be handled. The, n8 [, s) X$ @/ c
proposal is attached.( g% H, W3 j" m4 \" A
Decision:, }- j4 M7 z2 z2 S! h3 N
Use of non-separable thin sheet insulation in wound components
+ i* K/ n, ^$ U$ U, I7 ?The following proposal shall be used until the new edition is published.
# e4 c3 V. F8 u1. Introduction
. @- j1 }+ {7 K* ]This document presents two alternative versions of the test procedure given in IEC0 Z8 d) t) T7 O7 B) |+ N
61558-1 for checking the mechanical durability of thin sheet materials.
# H3 L# P. W T. k$ M$ pTest method X adapts the published procedure to the conventions and practices used in
+ i: [7 s# Y k% |+ v, Z! Y* jIEC 60950. In Method X, the metal foil is secured to the sample prior to the test.+ X# l6 F" }: Z. d$ d: u* x2 {) |
Test method Y is the slightly different procedure observed on a video presentation,
4 E2 y& g7 g, P. ^# x, r" M. Ewhereby the metal foil is only added to the test assembly after the sample has been
, z$ u; P' K! h1 z2 o1 L/ P$ Lstressed by rotating it in the test fixture.7 v" S; v* A2 w" v
Test method Y appears to be the more practical method, and is evidently how the test is
+ S, i m% w2 h, @0 scarried out in at least one test laboratory. The two methods should give the same results.8 B2 W/ k0 A* S* `0 }! P0 i
2. Proposal1 S6 e% {+ ]/ s
Change the title of 2.10.5.2 to the following:
! {' j4 g/ V5 ]# h' F1 p2 v' ^2 a2.10.5.2 Separable thin-sheet material" N4 M( r% b+ z [7 t' s
Modify the first paragraph of 2.10.5.2 as follows:
B7 y% o! p2 V( H' P4 cInsulation in separable thin sheet materials, and in two layers of non-separable thin sheet
7 e! A; [/ D4 V: v, C( W( Kmaterials, is permitted, ….' i; K) p+ b$ o$ q, r' L
Add a new sub-clause 2.10.5.X or 2.10.5.Y.
% r+ V& V/ V: ?# ETest Method X. D+ o1 V& W/ _5 k2 y% V
2.10.5.X Non-separable thin sheet material u/ l; G. \- ^1 ~
Insulation in three or more layers of non-separable thin-sheet materials is permitted for use within; k! V. K, _2 T3 y o7 I2 W; ]( K
the equipment ENCLOSURE, and shall not be subject to handling or abrasion during servicing. It
1 j8 T& |( S' M4 f, \3 |shall have adequate mechanical strength.
. V$ ?2 d! r: I& w& |6 r' l yNOTE - The purpose of the tests in 2.10.5.X is to reveal defects that are hidden in inner layers of insulation,
8 m# S& P1 _& p6 D! f+ oso there is no test for insulation in two layers. For insulation in two layers of non-separable thin-sheet
, i& O! H1 s6 X7 E+ ~. x0 amaterials, see 2.10.5.2 O1 p& a! ~" `) @
There is no requirement regarding distances through insulation, nor for all layers of insulation to be
# f* T m Q+ w+ nof the same material.! T9 R! Z2 I# M+ s: W
Compliance is checked by inspection and by the following test:
9 ~( F6 S: s5 q; F6 wThree test samples of thin sheet material are used, each approximately 70 mm wide.
, O- s3 Q+ v" D) }9 i( fOne sample is fixed to the mandrel of the test fixture as shown in figure 5X.
. M( {' U4 b9 W+ \! vA sheet of aluminium or copper foil, 0,035 mm ± 0,005 mm thick, approximately 30 mm wide and at/ u1 C Y& w) J/ e$ u
least 100 mm long, is fixed to the surface of the sample. The foil is positioned so that its edges are; S7 h. F& q0 B# G
approximately 20 mm from the edges of the sample (see figure 5Xd) and so that when the
1 h' {, p' l, Y# F/ E! ~, |; Imandrel is in its final position, the foil overlaps the free end of the sample by at least 10 mm (see9 s# m8 q9 j% c% B" y0 ]. y
figure 5Xc). The foil is tightened by a pull of approximately 1 N, using an appropriate clamping. S7 J* |9 q$ j( e) j2 U
device.
! e( {3 q( A, F2 L; N9 sA pull of 150 N is applied to the free end of the sample, using an appropriate clamping device. The* j# f1 B6 E4 Y5 r8 J1 A
mandrel is twice rotated forwards and backwards by 230°, and then forwards to the final position.
$ x& S3 o2 o: W( nWhile the mandrel is in its final position, and within the 60 s following the final positioning, an% ?3 T8 P5 I; k) R
electric strength test is applied between the mandrel and the metal foil in accordance with 5.2.2,7 ]3 y; k% e0 N$ F1 i' \( Z% D
using a test voltage of 1,5 times the value specified in table 5B., c- {, O2 x3 ?. X7 q1 O
The test is repeated with the other two samples4 j2 O" H; _3 k/ `
If a sample breaks at the clamping device during rotation, the test is repeated on a fresh sample. If
; r" y% H3 N8 @8 U3 Oone or more samples breaks at any other place, the test has failed.
1 m" T6 t% O1 n! Q6 r............................2 }8 W7 B+ f4 i
Add new Figure 5X (adapted from Figure 6 of IEC 61558-1)1 [ j4 V1 c! w. i
Figure 5Xa is as figure 6a of IEC 61558-1, modified as follows:
/ p. |2 L: R) Z& J6 h# q1 QReplace "3 x R = 0,5 ± 0,02" by "R = 0,5 ± 0,02 (typ)"
: u2 K. j# D$ ?/ C7 HReplace "Material: steel nickel plated or brass" by "Material: metal"3 N/ ]9 M! `9 \
Figure 5Xd is the same as figure 6c of IEC 61558-1* p! j1 c3 l- g! G+ v+ @
Test Method Y
: G2 i6 \7 d6 J3 |7 t! M2.10.5.Y Non-separable thin sheet material
! |/ F$ e( {$ |- a. z% fInsulation in three or more layers of non-separable thin-sheet materials is permitted for use within
7 b3 C- N! n- e# a% k, Lthe equipment ENCLOSURE, and shall not be subject to handling or abrasion during servicing. It- f+ A+ H5 j% j3 d9 U e
shall have adequate mechanical strength.
" m2 b/ E3 I' ~( KNOTE - The purpose of the tests in 2.10.5.y is to reveal defects that are hidden in inner layers of insulation,7 S& ]5 |9 B4 s0 R/ F1 ]/ _7 } k% Y
so there is no test for insulation in two layers. For insulation in two layers of non-separable thin-sheet
" p, _7 N' }( i. y) Pmaterials, see 2.10.5.2, t8 t# G% o8 Z# B ?
There is no requirement regarding distances through insulation, nor for all layers of insulation to be
8 L$ j5 Y( S8 D5 t3 T. i/ r9 nof the same material.( F ?" j7 \ j! b* k/ P9 V
Compliance is checked by inspection and by the following test:; l6 e5 ~" Y3 b) \3 u* z
Three test samples of thin sheet material are used, each approximately 70 mm wide.. C/ X+ e" F2 Q4 W: j2 X6 y' s' I
One sample is fixed to the mandrel of the test fixture as shown in figure 5Y.- F& W' v5 B% q( ], M9 T
A pull of 150 N is applied to the free end of the sample, using an appropriate clamping device. The6 T- S- c0 |5 F6 s+ {8 G) M$ q: A8 X
mandrel is twice rotated forwards and backwards by 230°, and then forwards to the final position.7 i6 X. |( `# ^* S; g
A sheet of aluminium or copper foil, 0,035 mm ± 0,005 mm thick, approximately 30 mm wide and at/ l2 r1 O8 ^( P0 f
least 200 mm long, is placed across is the surface of the sample, hanging down on each side of
: S: O2 a1 V7 b* Y/ t9 K ythe mandrel. The foil is tightened by a pull of approximately 1 N at each end, using appropriate
; W q: M2 v4 U$ d5 ~clamping devices.. The foil is positioned so that its edges are approximately 20 mm from the edges
) n" W6 w4 ^; Q8 sof the sample (see figure 5Yd).
! L6 p i% A0 v; l: s- Z+ T F0 vWhile the mandrel is in its final position, and within the 60 s following the final positioning, an
6 B' F D( z# X' @# t. h n; Zelectric strength test is applied between the mandrel and the metal foil in accordance with 5.2.2,
& w4 V: X* ~7 S0 l. wusing a test voltage of 1,5 times the value specified in table 5B.
8 s S n8 J) \5 d' [The test is repeated with the other two samples
8 V0 ?5 n* f0 Z0 jIf a sample breaks at the clamping device during rotation, the test is repeated on a fresh sample. If
r+ a" M% M- \8 Qone or more samples breaks at any other place, the test has failed.) F! q- H$ w5 { [4 Y( d8 a5 s
...............................: `- c2 A6 H' _
Add new Figure 5Y (adapted from Figure 6 of IEC 61558-1) r3 G0 S8 g( a/ s' e
Figure 5Ya is as figure 6a of IEC 61558-1, modified as follows:
3 t# K9 C' ~8 D" x6 v$ g, ]Replace "3xR = 0,5 ± 0,02" by "R = 0,5 ± 0,02 (typ)"
" T! L* ~8 Y) GReplace "Material : steel nickel plated or brass" by "Material: metal"
- V+ ~" A' @% s Z: W: x' h9 `Figure 5Yd is the same as figure 6c of IEC 61558-15 f7 \& g c% K6 q
/ [3 J' k; P6 h4 k5 o- e# x
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( Y2 f) T% g* h) p' ~: [& K6 d3 W: B- o P0 n
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