|
参考一下UL2021:7 [$ j8 Q, e5 o# i4 f1 B
15.2 Protection of wiring) q1 o( d2 y. N$ L5 F9 o: A
15.2.1 The wiring and connections between parts of a heater shall be protected or enclosed, except that& R' H$ l, d, c2 S9 v1 u
a length of flexible cord may be employed for external connections, or for internal connections that may3 G* o' i* v& r# q9 p3 i
be exposed during servicing, if flexibility of the wiring is essential.
9 }5 q- q4 _4 _# y i* j, v4 X15.2.2 The internal wiring of a heater in the vicinity of a lampholder that accepts either an infrared lamp
! F3 e* }7 o: o$ b$ A2 j+ Wor an ordinary lamp:/ W* b3 o* V+ ^* T- R4 s! P5 \+ E1 |
a) Shall be a jacketed type at least equivalent to Type SP-2 flexible cord. Asbestos-insulated
+ ]9 A& n+ f, ]) t. {/ F5 P1 ?wiring and appliance wiring material is not acceptable unless provided with sleeving or tubing.
* f1 S2 z' h! {2 tb) Shall be routed along the metal surface of the heater enclosure and shall be so secured as
$ d; f6 `6 ?- E& Tto minimize the likelihood of its being hooked or grasped.
1 v6 P; [, ?( @9 V b& e15.2.3 A conductor utilizing beads for insulation shall not be used outside an enclosure.
% o3 }. l: X* @$ r6 g+ `; F0 d6 t15.2.4 Internal wiring that is exposed through an opening in the enclosure of a heater is considered to be! G) H* ^4 E) _" a, ~
protected as required in 15.2.1 – 15.2.3 if, when judged as though it were film-coated wire, the wiring
" Y7 z* {1 e f+ ]would be acceptable according to 7.17– 7.20. Internal wiring within an enclosure is acceptable if, even
- W# Z7 T& l, V$ z0 Athough it can be touched with the probe, it is so protected or guarded that it cannot be grasped or hooked
6 O# }& n3 z8 f' O! |3 \4 `( Din such a manner that it could be subjected to stress. |
|