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12.7 Thermal test in regard to fault conditions in lamp controlgear or electronic
% F1 i, S8 c! G4 O4 Xdevices in plastic luminaires3 p' D* f) d4 J$ w' P! u: P0 g
The test applies only to luminaires with a thermoplastic housing not fitted with an extra; P ]2 I- ?1 L3 O
mechanical temperature-independent device as per 4.15.2.
5 y+ s) u% |9 l X) q; g/ o; i- W, ?* k4 a, E) N8 Q- H5 M
12.7.1 Test for luminaires without temperature sensing controls/ l. }2 V1 _! |6 @7 y7 v. E$ c) z g) |4 ~
The luminaire shall be tested under the conditions specified in items a), c), e), f), h) and l) of i* u- r& \+ a! l
12.4.1. In addition, the following also applies.
/ w7 k& v# @3 o20 % of the lamp circuits in the luminaire, and not less than one lamp circuit, shall be
4 a9 B9 F. r* ?2 v7 h" Dsubjected to abnormal conditions (see item a) of 12.5.1).
4 S+ P4 I; J* RThe circuits which have the most thermal influence on the fixation point and exposed parts1 v* {" D7 o7 y* L5 y- j" E8 r; e
shall be chosen and other lamp circuits shall be operated at rated voltage under normal3 O. x( p- `/ C7 }
conditions.% X: x5 k/ w$ D( n2 v9 {1 c
The circuits subjected to abnormal conditions shall be operated at 1,1 times (the rated voltage3 m% N+ J2 t3 p4 P
or the maximum of the rated voltage range). When conditions are stable, the highest winding. B% r- ^- c, M7 B
temperature and highest temperature of fixing points and most thermally influenced exposed& `5 v: K* @8 K2 M& q' ]
parts shall be measured. It is not necessary to measure the temperature of small wound* b' @) E: q* v; n$ p4 v4 B( P2 i% b
devices that are incorporated within electronic circuits.
) t5 w: _5 q: r+ BCompliance) {5 d: E" X g7 x6 {/ |, D
The values of the ambient temperature and the temperature measured at 1,1 times (the rated
* v- e- N7 r8 D S$ h% b) Qvoltage or the maximum of the voltage range) are used for the linear regression formula in
, m! b+ N n" T$ g, I! Rcalculating the temperature of fixing points and other exposed parts in relation to a
, r9 I, Q% Z9 E; lballast/transformer winding temperature of 350 °C. The calculated value shall not exceed the0 K! C% n ~5 }9 `
temperature of the deflection under load of the material in accordance with method A as
6 a. K" g7 u# Y0 E odefined in ISO 75 (1987), Plastics and ebonite – Determination of temperature of deflection
; A# R9 Y0 t9 J; P) K( Qunder load.& f `7 E# c A* ]9 H3 U9 H, H% c5 L
12.7.2 Test for luminaires with temperature sensing controls internal/external to the
* f' [ k/ e y' @( K f8 Yballast or transformer q9 @& P' W6 g" o: u$ c9 Q w
The luminaires shall be set up for this test as described in the first three paragraphs of 12.7.1.
5 c7 G: S& }0 ~
+ Q7 G3 D1 q b4 D: yThe circuits subjected to abnormal conditions shall be operated with a slowly and steadily/ I) m) W6 R3 D. o `2 A8 h& O
increasing current through the windings until the temperature sensing control operates.) f7 R& b( v0 W! d2 H
Time intervals and increments in current shall be such that thermal equilibrium between
7 w. u# W) }; |+ nwinding temperatures and temperature of fixing points and most thermally influenced exposed7 f2 m8 Y8 B8 S6 \ Y
parts is achieved as far as is practicable. During the test, the highest temperature of the spots
' v$ S9 X: J& {tested shall be continuously measured.# i0 n7 j7 R( f8 N0 a5 r# {
For luminaires fitted out with manual-reset thermal cut-outs, the test shall be repeated six) T9 Z8 ~$ X6 r2 t& I
times allowing 30 min intervals between tests. At the end of each 30 min interval, the cut-out; O% O9 s1 }) r, C5 Y/ u
shall be reset.0 {7 p/ |4 x( Y* Y( e) s3 \
For luminaires fitted out with auto-reset thermal cut-outs, the tests shall be continued until a
' v+ H- D6 i1 r5 J5 ~( Estable temperature is achieved.
, a& O6 O/ r2 G) o8 S, oCompliance- L/ u `& S6 u# m l
The highest temperature of the fixing points and most thermally influenced exposed parts,$ K2 f6 t/ K4 I& H T5 @% |
shall not exceed the temperature of deflection under load of the material according to the& c4 j1 g1 L7 z# ?
method A as defined in ISO 75, at any time during the tests for thermal links, manual-reset( N. e; U1 a" h3 r# }* M$ s/ O
thermal cut-outs, and auto-reset thermal cut-outs.7 @6 T2 ~; W$ C; O9 l1 L w" G
In applying the requirements of 4.15 and 12.7 the following notes are to be referred to:
9 i( e$ i9 v: `+ h, N, `1 r2 w* x" ^NOTE 1 - ‘Fixing points’ means both the fixing points of components and the fixing points of a luminaire to the
+ t4 t7 E) j6 L- g9 t* z) Tmounting surface.
. k' U% D4 {3 \
; I o, n" J' [/ Z9 iNOTE 2 - ‘Exposed part’ means the outer surface of the luminaire enclosure.7 k5 v2 H5 w+ f
NOTE 3 - Measurement of exposed parts is restricted to those parts providing the luminaire/component fixing or
' l; k& M2 Y% `' z- w/ \ Kparts providing a protective barrier against accidental contact with live parts, as required by section 8 of this
. t e `; D( kstandard.) X4 r x9 m) j6 d: t0 M
NOTE 4 - The hottest part of the thermoplastic material section requiring test is measured. This may often be on
% {8 [2 a. H, K |: l2 ?" A- a Pthe internal surface of a luminaire enclosure not the outer surface.
* x c/ R/ I" `( qNOTE 5 - The material temperature limits defined by clause 12.7 are with respect to materials under both
% h0 T& D' c& d% Q7 F3 Y5 Qmechanical load and no mechanical load.( y) \* e. | w4 a3 M$ ^
NOTE 6 - The application of clause 12.7 must be read together with the requirements of sub-clause 4.15. |
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