|
4.9 Insulating linings and sleeves& d- O2 o7 T, v% ]: d
4.9.1 Insulating linings and sleeves shall be so designed that they are reliably retained in
+ |4 [% p+ P4 ^8 R& F6 E0 ^position when switches, lampholders, terminals, wires or similar parts have been mounted.
% |2 h" F5 W0 L/ b1 ONOTE Self-hardening resins, such as epoxy resins, may be used to fix linings.
( H& W. i. w% q! R' m2 O* OCompliance is checked by inspection and by manual test.! u# E& g3 S7 d; I8 I0 H
4.9.2 Insulated linings, sleeves and similar parts shall have adequate mechanical, electrical7 a. p7 d+ N7 p/ p$ q! L9 }2 |
and thermal strength.
1 @4 N( U0 w$ p2 \* {Compliance is checked by inspection, by manual test and by the electric strength test in) T9 |5 i% P8 e' x
accordance with Section 10. The thermal properties of wire and sleeve are checked in
6 c9 d+ P# G' f# j2 m$ a. ~$ K7 aaccordance with Section 12. Heat resistant sleeves used as covering for wires attaining a
0 O0 F; A9 F3 o! e2 ~; Ytemperature exceeding the values given in Table 12.2 of Section 12 shall comply with the3 f: a" @" @/ y' ~' `- A
requirements of IEC 60684, taking into account the temperature measured on the wire in7 d' Y* u4 P2 j2 ]
question. The sleeve shall be resistant to a temperature exceeding the temperature measured* l8 |2 e0 }% \3 A
on the wire by 20 °C or withstand the following test:
% \& c! n, a# x2 s: h/ ~; @. p. aa) Three test specimens of the sleeve, about 15 cm in length, are subjected to the humidity5 U% }% ?7 x0 @3 T8 y2 Y( n
test of 9.3 and subsequently to the insulation resistance and electric strength tests0 ^+ z; c( M7 c% e# ~* t! W
according to Section 10. A suitable uninsulated copper conductor or metal rod is passed7 K( t! [. B8 U. v/ p2 t
through the specimens, and the outside is covered by a metal foil in such a way that no/ s% X7 a2 e* n& `
flashover at the ends of the samples can occur. The measurement of the insulation
+ V. k4 j# S. t4 {9 F! B: vresistance and the electric strength test is then made between the copper conductor/metal: p( ]; o- ~0 R
rod and the metal foil. [7 b' ~ M4 X9 }2 W( O
b) After the copper conductors/metal rods and metal foils have been removed, the specimens
$ a' O2 ]& d0 b5 N/ Yare placed in a heating cabinet for 240 h at a temperature of T + 20 °C, T being the
7 i! y3 |( Q: @$ u% x9 zmeasured temperature of the wire.
- ^6 J' O5 V: s oc) The specimens are allowed to cool to room temperature and are then prepared as indicated) f6 S9 z, ]5 e& `. y! h
under item a) above.
9 _8 \8 @1 ]5 ^) p, Z: }Measurement of the insulation resistance and electric strength is then made between the0 \3 R8 D: D* Z: ~ F- {3 f
copper conductor/metal rod and the metal foil.4 \- C+ M; O/ X6 Z. u. D# R
Compliance is checked by the insulation resistance values and test voltages specified in8 ~* j" X" [; O# Y$ O
Tables 10.1 and 10.2 in Section 10. |
|