|
EN60950-1:2006
% l0 `; U% S9 L+ y" Q4.2.7 Stress relief test
0 Z$ ~3 C" S3 D2 |5 }* [, B" ]ENCLOSURES of moulded or formed thermoplastic materials shall be so constructed that any
! P% }& F# ?: P* o: lshrinkage or distortion of the material due to release of internal stresses caused by the
: T, u" {( c& h2 P( R7 gmoulding or forming operation does not result in the exposure of hazardous parts or in the
$ O j# h( R2 o8 ereduction of CLEARANCES or CREEPAGE DISTANCES below the values specified in 2.10 (or, v! Y$ u7 V8 U6 M, n
Annex G).0 h: D( r3 D C" P. G. N
Compliance is checked by the test procedure described below or by the inspection of the
( I9 u7 A: @8 |: Nconstruction and the available data where appropriate.
) J+ b) @/ b" f$ v1 kOne sample consisting of the complete equipment, or of the complete ENCLOSURE together
& L& X) o' B, ~/ A$ _0 h3 `with any supporting framework, is placed in a circulating air oven (according to
% j- d8 p1 R# @. i* K! lIEC 60216-4-1) at a temperature 10 K higher than the maximum temperature observed on the* s# l0 K8 l, e: Z$ E
ENCLOSURE during the test of 4.5.2, but not less than 70 ° C, for a period of 7 h, then permitted
9 S' f* u: Y7 k3 Nto cool to room temperature.
7 Q' J* d' [: h6 t2 J6 lWith the concurrence of the manufacturer, it is permitted to increase the above time duration.
* ]$ B& N6 }- W: p8 A* yFor large equipment where it is impractical to condition a complete ENCLOSURE, it is permitted
- y- ~* E- w: S. ?to use a portion of the ENCLOSURE representative of the complete assembly with regard to
) G/ [8 L h: f" Rthickness and shape, including any mechanical support members.! A4 N2 x. ^6 |8 F& M, j
NOTE Relative humidity need not be maintained at a specific value during this test.! O! G. t, V6 F; C1 f
If the above test is conducted, the compliance criteria of 4.2.1 apply. |
|