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EN60950-1:2006+ N6 V7 z4 e5 K$ |# [
4.2.7 Stress relief test
' d7 N' V) d/ j0 M/ C5 wENCLOSURES of moulded or formed thermoplastic materials shall be so constructed that any) L2 E) f/ }% S9 x0 d% h' b; ^/ Z
shrinkage or distortion of the material due to release of internal stresses caused by the: Q9 e5 H7 W2 n z, S2 f( V
moulding or forming operation does not result in the exposure of hazardous parts or in the
" d) }6 A1 D5 V) V& u4 Qreduction of CLEARANCES or CREEPAGE DISTANCES below the values specified in 2.10 (or' Q; q' \* s) `1 y: `# D! W; K, Y
Annex G).$ }1 D+ M' a- i( o9 f5 M3 r
Compliance is checked by the test procedure described below or by the inspection of the4 _/ j: r6 H# e9 u9 m( ^
construction and the available data where appropriate.' x2 ~" B- o, W: t. _2 G" _, {' m
One sample consisting of the complete equipment, or of the complete ENCLOSURE together n6 I. Y, d$ M/ q' h4 E
with any supporting framework, is placed in a circulating air oven (according to
; J; Y/ A) |$ `1 pIEC 60216-4-1) at a temperature 10 K higher than the maximum temperature observed on the
& }9 U. }; u! l. w! eENCLOSURE during the test of 4.5.2, but not less than 70 ° C, for a period of 7 h, then permitted4 h% N4 I0 R. \! Z% l5 Y# i) e
to cool to room temperature.
1 Q# I; p$ w& F$ E& b, a7 ^$ v nWith the concurrence of the manufacturer, it is permitted to increase the above time duration.
+ U' \" M0 \& l' I' a# ^For large equipment where it is impractical to condition a complete ENCLOSURE, it is permitted8 H9 U2 S/ t3 N# f0 ^( Z
to use a portion of the ENCLOSURE representative of the complete assembly with regard to. h" c. z6 @1 ]9 \" e! ]* C
thickness and shape, including any mechanical support members./ F! k5 ?3 A- e
NOTE Relative humidity need not be maintained at a specific value during this test.
$ k# S5 \0 t$ LIf the above test is conducted, the compliance criteria of 4.2.1 apply. |
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