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EN60950-1:2006
" V6 y0 f& E2 v. \7 z$ y+ T4.2.7 Stress relief test" s: T6 G" G; |( g
ENCLOSURES of moulded or formed thermoplastic materials shall be so constructed that any
( b* ~* S& b8 c5 U' @shrinkage or distortion of the material due to release of internal stresses caused by the
' q2 v" V" X5 i o s2 V$ Z! fmoulding or forming operation does not result in the exposure of hazardous parts or in the
# m, r( u: ?* \4 Preduction of CLEARANCES or CREEPAGE DISTANCES below the values specified in 2.10 (or
$ ]; h8 p" U U: UAnnex G).
# y0 k) m! h2 D( X/ FCompliance is checked by the test procedure described below or by the inspection of the! I U5 }, b9 B- v8 }# N; w" v; j
construction and the available data where appropriate.
" {! j+ \; l- U8 y" ]One sample consisting of the complete equipment, or of the complete ENCLOSURE together
+ H# b; z8 x* pwith any supporting framework, is placed in a circulating air oven (according to) y6 \- R6 t0 r* K( d% ^
IEC 60216-4-1) at a temperature 10 K higher than the maximum temperature observed on the
$ a: l( S+ A0 e2 F- `1 p4 OENCLOSURE during the test of 4.5.2, but not less than 70 ° C, for a period of 7 h, then permitted
/ m; H6 Z8 o2 w, q8 r- p2 fto cool to room temperature.+ _* v+ c0 }% Y
With the concurrence of the manufacturer, it is permitted to increase the above time duration.$ |) t ~! {7 b
For large equipment where it is impractical to condition a complete ENCLOSURE, it is permitted0 W& S$ I$ {# r# i5 \- p$ \* c6 ]+ |
to use a portion of the ENCLOSURE representative of the complete assembly with regard to! L2 H9 l& Y" m; [ l) X! h8 K
thickness and shape, including any mechanical support members.
4 u8 x1 Y) ?1 R: kNOTE Relative humidity need not be maintained at a specific value during this test.
: Q/ }5 T9 ?. G0 F+ M; |If the above test is conducted, the compliance criteria of 4.2.1 apply. |
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