|
12.7 Thermal test in regard to fault conditions in lamp controlgear or electronic
2 X) ^) Y2 z8 x3 g3 S, ^' sdevices in plastic luminaires
. i' y+ n3 j: d7 p# nThe test applies only to luminaires with a thermoplastic housing not fitted with an extra
5 \ V+ A! A; K& f) @8 Dmechanical temperature-independent device as per 4.15.2.* ?9 X- C! _* ~: c7 t# P: n" n; U
4 [0 f4 Y' T0 y0 E2 E+ Z
12.7.1 Test for luminaires without temperature sensing controls3 ]- Z& _8 S* d2 s8 {- r
The luminaire shall be tested under the conditions specified in items a), c), e), f), h) and l) of
8 X- w- A8 T$ u8 _7 R$ N1 |9 y( X12.4.1. In addition, the following also applies.9 M5 y! G q3 n: N* S
20 % of the lamp circuits in the luminaire, and not less than one lamp circuit, shall be% q; q+ h- d* x% d
subjected to abnormal conditions (see item a) of 12.5.1).# K0 ^+ Y' P( {8 `+ b
The circuits which have the most thermal influence on the fixation point and exposed parts
* a! Q. A) v0 g9 hshall be chosen and other lamp circuits shall be operated at rated voltage under normal
! h" l x3 ~2 H* G3 S* @conditions.9 S b7 Z: V' R8 m) y5 T) }3 {$ | K6 z
The circuits subjected to abnormal conditions shall be operated at 1,1 times (the rated voltage' {0 g; L( t$ \3 ~# F
or the maximum of the rated voltage range). When conditions are stable, the highest winding8 z, N, L+ f, M' B2 ?- p
temperature and highest temperature of fixing points and most thermally influenced exposed
% ? A! b4 g8 Q# Nparts shall be measured. It is not necessary to measure the temperature of small wound
* [9 w, E& h( c7 V! \devices that are incorporated within electronic circuits.
. p' O0 ]& ^6 }Compliance" ~3 t( H1 ^% J5 {4 W
The values of the ambient temperature and the temperature measured at 1,1 times (the rated
+ y3 U, Q5 ^6 A/ A ]* j' T" Zvoltage or the maximum of the voltage range) are used for the linear regression formula in
' ^9 {9 s4 c7 l6 }4 j6 Kcalculating the temperature of fixing points and other exposed parts in relation to a
+ d$ y7 i6 \$ I( T2 P+ `) w" |ballast/transformer winding temperature of 350 °C. The calculated value shall not exceed the
/ V- t0 ~& v. B3 O. q. Etemperature of the deflection under load of the material in accordance with method A as/ m8 u$ o, l& o/ Y! R* J7 {
defined in ISO 75 (1987), Plastics and ebonite – Determination of temperature of deflection+ L, P, L- b+ a" w6 E1 N: y) {
under load.
$ N5 H! V) r/ L0 Q" }12.7.2 Test for luminaires with temperature sensing controls internal/external to the3 [2 J/ `& D5 m: |: L
ballast or transformer
" c7 I S( m1 y" WThe luminaires shall be set up for this test as described in the first three paragraphs of 12.7.1.# ]* y9 C2 J; \, G
! ]$ [- x5 J+ I
The circuits subjected to abnormal conditions shall be operated with a slowly and steadily& H( Z9 ]/ J8 C9 h% `0 Z
increasing current through the windings until the temperature sensing control operates.
6 B1 Z/ j; S0 n& `. F9 uTime intervals and increments in current shall be such that thermal equilibrium between6 Z J' u! p: @6 L" Q: v2 E7 o
winding temperatures and temperature of fixing points and most thermally influenced exposed# p8 f) H' o5 f, T" T5 c+ ^) B3 B' o6 m- r
parts is achieved as far as is practicable. During the test, the highest temperature of the spots/ o2 _* k4 Z2 ^6 `" p. z( N- a
tested shall be continuously measured.
4 e* e0 _) h) ]1 `0 x+ b% zFor luminaires fitted out with manual-reset thermal cut-outs, the test shall be repeated six% s- j/ |/ V8 ^0 U9 U! ?4 l
times allowing 30 min intervals between tests. At the end of each 30 min interval, the cut-out/ l) V1 r6 l* ?2 }5 M
shall be reset.
' _. P: J, v% G; D8 r! P$ t) VFor luminaires fitted out with auto-reset thermal cut-outs, the tests shall be continued until a
2 b$ }4 Y' q t; O, hstable temperature is achieved.
! O% p" }4 t) K9 {) @1 T( C9 CCompliance
* {+ r1 q3 ]$ jThe highest temperature of the fixing points and most thermally influenced exposed parts,
" J0 I1 y& N2 @* ?shall not exceed the temperature of deflection under load of the material according to the
! q9 d; ~/ A; |- r3 K! W. T3 }method A as defined in ISO 75, at any time during the tests for thermal links, manual-reset. H; \ [& z: x7 u3 |3 ^
thermal cut-outs, and auto-reset thermal cut-outs.6 r7 w6 D; _6 j1 i6 _* z: z' Q
In applying the requirements of 4.15 and 12.7 the following notes are to be referred to:5 e& i& `5 _9 {! a
NOTE 1 - ‘Fixing points’ means both the fixing points of components and the fixing points of a luminaire to the
8 u( }+ _- L$ L& t# i# C0 z. ?. |mounting surface.4 M8 ~1 c9 p4 n
2 j8 P. `# g1 |+ dNOTE 2 - ‘Exposed part’ means the outer surface of the luminaire enclosure.
, ~0 L0 E# W3 t3 a7 PNOTE 3 - Measurement of exposed parts is restricted to those parts providing the luminaire/component fixing or; P P P* w) D# x
parts providing a protective barrier against accidental contact with live parts, as required by section 8 of this
, y" ^4 Z3 ~1 Vstandard.3 V4 E0 h J' R8 T1 E3 u
NOTE 4 - The hottest part of the thermoplastic material section requiring test is measured. This may often be on
5 y5 N( p* I _0 Lthe internal surface of a luminaire enclosure not the outer surface.5 A# @# y. V* i( C( F _( `
NOTE 5 - The material temperature limits defined by clause 12.7 are with respect to materials under both
/ L; {! @$ I# E3 mmechanical load and no mechanical load.
- i1 M+ ?: [& Q3 dNOTE 6 - The application of clause 12.7 must be read together with the requirements of sub-clause 4.15. |
|