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12.7 Thermal test in regard to fault conditions in lamp controlgear or electronic
5 g9 k! m1 K% s1 r I+ j0 Edevices in plastic luminaires
- g3 z: Z4 V: }+ R* e# d( dThe test applies only to luminaires with a thermoplastic housing not fitted with an extra$ M( o* Z) L% Q
mechanical temperature-independent device as per 4.15.2.' b" w9 T5 p) [9 q! g
3 p7 o& N. t+ {; Y12.7.1 Test for luminaires without temperature sensing controls: W* V$ j. \" v/ y3 B: r
The luminaire shall be tested under the conditions specified in items a), c), e), f), h) and l) of6 p: ~, a& n6 {; N8 e _
12.4.1. In addition, the following also applies.0 a! V% R. x4 V) W& C! V7 b
20 % of the lamp circuits in the luminaire, and not less than one lamp circuit, shall be
) @' Y# T; [' x8 _7 }subjected to abnormal conditions (see item a) of 12.5.1).. @7 G2 z6 u) ~3 w L! |
The circuits which have the most thermal influence on the fixation point and exposed parts( Y @" F5 ]7 G* |# e3 M4 d
shall be chosen and other lamp circuits shall be operated at rated voltage under normal3 A1 T& J5 A5 m3 Z6 g3 t8 D4 Y
conditions.; a' a( x: N1 c/ I, {3 Z
The circuits subjected to abnormal conditions shall be operated at 1,1 times (the rated voltage
: j% m5 V* ]5 O ?2 O6 n6 a* ]/ D3 gor the maximum of the rated voltage range). When conditions are stable, the highest winding
. ~- t; ~4 B) i+ xtemperature and highest temperature of fixing points and most thermally influenced exposed! P) K% W0 K1 H
parts shall be measured. It is not necessary to measure the temperature of small wound
4 x$ y: a1 f5 p& Zdevices that are incorporated within electronic circuits.* l# ?# x7 s- T% A6 Y
Compliance$ b9 R/ }5 f* i" v6 l
The values of the ambient temperature and the temperature measured at 1,1 times (the rated& `/ f& u, b( u; @5 S5 m+ E0 t
voltage or the maximum of the voltage range) are used for the linear regression formula in
9 q. o/ s& l+ T8 @; f5 _6 Fcalculating the temperature of fixing points and other exposed parts in relation to a5 |" j2 R4 g8 M
ballast/transformer winding temperature of 350 °C. The calculated value shall not exceed the) K( s. j0 X3 ?0 B+ Z5 y h
temperature of the deflection under load of the material in accordance with method A as( ]) j5 ^* V1 g8 F7 Y2 |6 p
defined in ISO 75 (1987), Plastics and ebonite – Determination of temperature of deflection7 k! m3 Z3 q* V- ]( A( t; H
under load.! R3 e1 U# l0 W
12.7.2 Test for luminaires with temperature sensing controls internal/external to the
; N. P. ^' ~2 r5 K, c& R; [ballast or transformer1 z& _, u( P2 d/ l1 W
The luminaires shall be set up for this test as described in the first three paragraphs of 12.7.1.4 M- ^- H; C" r. p2 _) y
3 ~2 n- `1 c9 \. e4 X% @+ s5 h
The circuits subjected to abnormal conditions shall be operated with a slowly and steadily
5 x F m7 h5 p( y0 h' q4 Fincreasing current through the windings until the temperature sensing control operates.: E' l( {# d" ^1 r. ~- }: i
Time intervals and increments in current shall be such that thermal equilibrium between4 i% D9 a6 q) F, @
winding temperatures and temperature of fixing points and most thermally influenced exposed
& U3 j+ q# y+ ~+ qparts is achieved as far as is practicable. During the test, the highest temperature of the spots
& z$ G+ q( Y/ N/ ^3 h! M2 atested shall be continuously measured.
! |6 F) @- f' Y; Y% AFor luminaires fitted out with manual-reset thermal cut-outs, the test shall be repeated six
6 t0 y( O" f$ l6 ttimes allowing 30 min intervals between tests. At the end of each 30 min interval, the cut-out
" C3 Q: o- |. c: w& `% t* dshall be reset.: M" I( ?4 x/ U
For luminaires fitted out with auto-reset thermal cut-outs, the tests shall be continued until a
# b. c4 {* n/ ^. I' cstable temperature is achieved.
; n( e* l; [: y' ]Compliance: A8 r7 l+ n! R' q- w
The highest temperature of the fixing points and most thermally influenced exposed parts,4 k% v8 o3 t# }: O
shall not exceed the temperature of deflection under load of the material according to the' K3 D( \# a5 D4 V
method A as defined in ISO 75, at any time during the tests for thermal links, manual-reset
9 I' R8 L3 x& j: xthermal cut-outs, and auto-reset thermal cut-outs.2 z4 g+ [. g: A
In applying the requirements of 4.15 and 12.7 the following notes are to be referred to:
* H7 V4 l3 L# xNOTE 1 - ‘Fixing points’ means both the fixing points of components and the fixing points of a luminaire to the
8 A; u5 Y: Z8 S. j- K1 f& gmounting surface.
' I4 t2 r; d1 z4 L& x4 g
8 w% t2 B+ q( h3 jNOTE 2 - ‘Exposed part’ means the outer surface of the luminaire enclosure.
) C: r. P) } v, XNOTE 3 - Measurement of exposed parts is restricted to those parts providing the luminaire/component fixing or K" j2 i/ ^5 w1 f) ]7 j
parts providing a protective barrier against accidental contact with live parts, as required by section 8 of this% R( w: e- J; `
standard.
' |# x/ E0 G, G P: XNOTE 4 - The hottest part of the thermoplastic material section requiring test is measured. This may often be on
4 r% n: X! `! y' W: T# v3 X; a: tthe internal surface of a luminaire enclosure not the outer surface.
5 e9 J: Q5 _1 c Z l: V2 W- sNOTE 5 - The material temperature limits defined by clause 12.7 are with respect to materials under both! y. ^; q) c/ h/ Q
mechanical load and no mechanical load.
; F4 p E* G7 Z2 a2 `9 [$ {NOTE 6 - The application of clause 12.7 must be read together with the requirements of sub-clause 4.15. |
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