|
20.1.3 PRINTED BOARDS; u+ K* C' P3 O1 V0 |, F
Base material of PRINTED BOARDS, on which the AVAILABLE POWER at a connection exceeds
$ `: C$ X" U, C2 l) Z: `15 W operating at a voltage exceeding 50 V up to and including 400 V (peak) a.c. or d.c. under& N1 t) a0 f& R% h: v
normal operating conditions, shall be of flammability category V-1 or better according to
, q$ C! w" g3 V- e2 T, |IEC 60695-11-10, unless the PRINTED BOARDS are protected by an enclosure meeting the0 ^2 i" x, q& Y
flammability category V-0 according to IEC 60695-11-10, or be made of metal, having openings
; c9 F' Y5 R; N$ b1 o7 y& fonly for connecting wires which fill the openings completely.' U1 n) ^( z5 a: a9 C9 |7 U, y6 r
Base material of PRINTED BOARDS, on which the AVAILABLE POWER at a connection exceeds 15 W
. {+ j' @$ |' k: H; toperating at a voltage exceeding 400 V (peak) a.c. or d.c. under normal operating conditions, and
: x+ R( ~0 ~! ebase material of PRINTED BOARDS supporting spark gaps which provide protection against
# l% v3 ] O7 j! h7 d* @overvoltages, shall be of flammability category V-0 according to IEC 60695-11-10, unless the
' j3 j# w9 \. _0 U/ QPRINTED BOARDS are contained in a metal enclosure, having openings only for connecting wires. p/ }0 D1 }) i
which fill the openings completely.5 K: b/ a. u+ p: E( d8 t- \
Compliance is checked for the smallest thickness of PRINTED BOARD used, in accordance with! i6 |$ j& B! n o
either:- [: R/ Y6 A( A7 h9 b
a) IEC 60695-11-10; or
! H$ F/ j3 H( P: {b) with Clause G.1 on specimens of boards as used in the apparatus, but without components. _! ?. J, ~. u% n6 u& ?
The tests under b) are performed after a preconditioning of 24 h at a temperature of4 t4 {. s' o$ X0 P$ R
(125 ± 2) oC in an air-circulating oven and a subsequent cooling period of 4 h at room
* C# {0 ]; N, A1 i1 T. mtemperature in a desiccator over anhydrous calcium chloride.5 U8 J8 x1 C m' ~
+ h. m1 ~: z# m: P$ e* e, ]PCB 的要求 |
|