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12.7 Thermal test in regard to fault conditions in lamp controlgear or electronic
$ t4 ?& S2 y3 C4 [, Wdevices in plastic luminaires. `8 c& |- A; ?9 U: h
The test applies only to luminaires with a thermoplastic housing not fitted with an extra3 N7 v0 f" ^9 v0 r6 X$ D
mechanical temperature-independent device as per 4.15.2.; d3 V# l; C* S0 u
0 n5 X5 ?$ `* h% j5 f. p12.7.1 Test for luminaires without temperature sensing controls- ]+ o7 }; P# I$ P% J9 }. J
The luminaire shall be tested under the conditions specified in items a), c), e), f), h) and l) of
) [; S6 s: @7 |. j/ U12.4.1. In addition, the following also applies.
/ y' L3 y* \4 G5 J- i+ m1 [20 % of the lamp circuits in the luminaire, and not less than one lamp circuit, shall be* {; j! A# ~" F: a) K( `
subjected to abnormal conditions (see item a) of 12.5.1).- v2 l8 m) D+ |4 Z1 ~# K
The circuits which have the most thermal influence on the fixation point and exposed parts
: ^0 u9 k4 [4 O6 H9 v$ ?shall be chosen and other lamp circuits shall be operated at rated voltage under normal: A) l, R$ |9 A* b$ z: a
conditions. R9 e6 T4 D8 Z+ A
The circuits subjected to abnormal conditions shall be operated at 1,1 times (the rated voltage; O- }) J5 F, q2 c
or the maximum of the rated voltage range). When conditions are stable, the highest winding7 k, A0 {& `7 h" l' L: }
temperature and highest temperature of fixing points and most thermally influenced exposed; h2 u# l$ w$ B
parts shall be measured. It is not necessary to measure the temperature of small wound
( \( i! t5 L3 v6 _2 xdevices that are incorporated within electronic circuits.
* Z& w6 ^4 g$ OCompliance
3 ]0 L" x' G$ m$ f6 AThe values of the ambient temperature and the temperature measured at 1,1 times (the rated2 }- f" N% d8 { V5 [$ q; w
voltage or the maximum of the voltage range) are used for the linear regression formula in& b- j6 {1 l3 |' u/ b1 X( A
calculating the temperature of fixing points and other exposed parts in relation to a
9 P, Z- g+ g- u- W0 ]5 i! L+ C# hballast/transformer winding temperature of 350 °C. The calculated value shall not exceed the8 K; y/ |, h3 l
temperature of the deflection under load of the material in accordance with method A as
7 {! O# D* ?( sdefined in ISO 75 (1987), Plastics and ebonite – Determination of temperature of deflection: q3 ?! P- B: m6 B: j5 I$ y0 K3 p
under load.. T4 j6 c1 j; e/ v
12.7.2 Test for luminaires with temperature sensing controls internal/external to the
! ?0 D) F& \) s2 j' ~) `5 {" O: C1 L6 gballast or transformer9 w% l. U5 p! H/ m
The luminaires shall be set up for this test as described in the first three paragraphs of 12.7.1.& S5 k: Z- G) Z, s
" s$ H) \& Y" ^1 U4 z- |. @
The circuits subjected to abnormal conditions shall be operated with a slowly and steadily
, B5 m& C: [3 V% X, q! fincreasing current through the windings until the temperature sensing control operates.( i2 V. x% R! I" c
Time intervals and increments in current shall be such that thermal equilibrium between1 M0 i! T* W5 q: u$ P `# P
winding temperatures and temperature of fixing points and most thermally influenced exposed, P$ s- g- r( j! S. e* f5 h
parts is achieved as far as is practicable. During the test, the highest temperature of the spots
) y G, t! F5 e: stested shall be continuously measured.2 k$ K" b! P! f: C" r, @
For luminaires fitted out with manual-reset thermal cut-outs, the test shall be repeated six
' T( g/ A$ c7 V8 W5 R/ |! Q. ~0 otimes allowing 30 min intervals between tests. At the end of each 30 min interval, the cut-out
( {4 _( N& j/ A3 }shall be reset.4 M% k! a* E' i6 o, b$ T
For luminaires fitted out with auto-reset thermal cut-outs, the tests shall be continued until a
( g4 S- u( u" P+ N+ E& Wstable temperature is achieved.$ u; J: n/ R9 J
Compliance5 O; N: p% X' ?7 Z8 n# Z' \
The highest temperature of the fixing points and most thermally influenced exposed parts,) H* p8 ]; M4 w1 L6 @: {
shall not exceed the temperature of deflection under load of the material according to the; w: }4 [( J! y. F" p
method A as defined in ISO 75, at any time during the tests for thermal links, manual-reset% W8 c* D9 {) b* C4 G+ ~, l
thermal cut-outs, and auto-reset thermal cut-outs.' l3 ?3 s6 Q) [% U
In applying the requirements of 4.15 and 12.7 the following notes are to be referred to:
! Z6 `& n2 P: }+ cNOTE 1 - ‘Fixing points’ means both the fixing points of components and the fixing points of a luminaire to the2 u: P G0 q7 w0 l. l3 _
mounting surface.
$ c! ]0 V" V( g& W4 E# _7 S! z- [+ R: g% P2 ], M
NOTE 2 - ‘Exposed part’ means the outer surface of the luminaire enclosure.
~) L7 \8 y+ k" g# M- S5 ANOTE 3 - Measurement of exposed parts is restricted to those parts providing the luminaire/component fixing or% q; v: e6 m" C# G+ |% A
parts providing a protective barrier against accidental contact with live parts, as required by section 8 of this5 F' B0 U+ Y. C1 B" f
standard.
+ z+ }8 g: q4 ~2 e% ONOTE 4 - The hottest part of the thermoplastic material section requiring test is measured. This may often be on
$ K4 G: f$ N5 d% v/ |the internal surface of a luminaire enclosure not the outer surface.
+ G0 p, e; ?. y" m6 C- yNOTE 5 - The material temperature limits defined by clause 12.7 are with respect to materials under both4 D2 I0 `- a+ a5 }! q
mechanical load and no mechanical load.
! C6 d! \4 `) c ^! GNOTE 6 - The application of clause 12.7 must be read together with the requirements of sub-clause 4.15. |
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