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12.7 Thermal test in regard to fault conditions in lamp controlgear or electronic
T# F" i2 p4 jdevices in plastic luminaires
) O% F( a$ A' k R& t+ t$ G4 NThe test applies only to luminaires with a thermoplastic housing not fitted with an extra f# V1 \% y5 e0 [' A; f
mechanical temperature-independent device as per 4.15.2.
. m1 J7 J4 e* t. S2 ~" ?8 N$ [- x1 w7 U. N
12.7.1 Test for luminaires without temperature sensing controls A$ x2 ?$ A8 M$ |, @+ l- A0 h6 i) [
The luminaire shall be tested under the conditions specified in items a), c), e), f), h) and l) of3 }* M5 i* H2 B2 I3 B
12.4.1. In addition, the following also applies.3 z! u2 E( M b" m' A( p R( K
20 % of the lamp circuits in the luminaire, and not less than one lamp circuit, shall be
: c% ~% X6 f2 i; tsubjected to abnormal conditions (see item a) of 12.5.1).4 W3 s5 h' I) F9 Z4 W
The circuits which have the most thermal influence on the fixation point and exposed parts3 V% L, n" T- v% e/ o
shall be chosen and other lamp circuits shall be operated at rated voltage under normal
' ]9 P* E, t' }" f7 Gconditions.: x: Q+ n4 B* f( t: j
The circuits subjected to abnormal conditions shall be operated at 1,1 times (the rated voltage2 s/ w% f3 q: f0 `# F2 i" S/ K
or the maximum of the rated voltage range). When conditions are stable, the highest winding
% E" m' I& E% H5 F; m8 j8 jtemperature and highest temperature of fixing points and most thermally influenced exposed" J6 ^6 l2 N7 c5 v& w+ w" Y( p% x
parts shall be measured. It is not necessary to measure the temperature of small wound
* a6 }2 [2 o5 O* I" @& adevices that are incorporated within electronic circuits.
1 _* l x# x0 o+ L. |# l% I- \Compliance) y6 b3 ~& E1 @
The values of the ambient temperature and the temperature measured at 1,1 times (the rated) a9 r3 c6 q) P6 m; `
voltage or the maximum of the voltage range) are used for the linear regression formula in
! G) Y6 _0 ?# d! T! W$ f/ `3 acalculating the temperature of fixing points and other exposed parts in relation to a0 }: g4 ]; y# G8 h' D
ballast/transformer winding temperature of 350 °C. The calculated value shall not exceed the$ c7 c9 d4 @: _/ M% r
temperature of the deflection under load of the material in accordance with method A as6 x- ~0 c' M6 _* b& }
defined in ISO 75 (1987), Plastics and ebonite – Determination of temperature of deflection
( l, r; K. Z8 ~8 }under load.
) T0 r! Z9 @1 t! B12.7.2 Test for luminaires with temperature sensing controls internal/external to the
# `4 m+ E! g0 L9 A, Zballast or transformer
9 u3 u" g" c7 bThe luminaires shall be set up for this test as described in the first three paragraphs of 12.7.1.! [5 [! O2 Z2 Y% }$ u4 t
: }2 s9 Q5 p0 `; uThe circuits subjected to abnormal conditions shall be operated with a slowly and steadily* n4 {* w2 ]# i
increasing current through the windings until the temperature sensing control operates.
) @# C3 H2 }5 s6 g$ g+ DTime intervals and increments in current shall be such that thermal equilibrium between% f1 B, W; e+ L; ^8 Z6 Z+ i
winding temperatures and temperature of fixing points and most thermally influenced exposed) s9 G; l$ J5 {& A r
parts is achieved as far as is practicable. During the test, the highest temperature of the spots! m1 |- R0 O6 j, a7 ~- d
tested shall be continuously measured.6 S- \) [9 ?! y/ h. f& S1 o4 z' _
For luminaires fitted out with manual-reset thermal cut-outs, the test shall be repeated six
# W) z3 b4 c* y( e) K% P, btimes allowing 30 min intervals between tests. At the end of each 30 min interval, the cut-out
& k' d h9 c6 g; V. @, Ushall be reset., H$ y) J0 j" T3 d* T
For luminaires fitted out with auto-reset thermal cut-outs, the tests shall be continued until a. N$ f) V; w6 K4 w' f8 j
stable temperature is achieved.8 d5 {/ g }+ d0 o
Compliance- V( y( O) \* f
The highest temperature of the fixing points and most thermally influenced exposed parts, D/ l7 e1 h/ e% t: J! V
shall not exceed the temperature of deflection under load of the material according to the! r% Z! ]% ?, F& P) K- `
method A as defined in ISO 75, at any time during the tests for thermal links, manual-reset
8 r* D5 R$ m5 N, `' z. J3 Gthermal cut-outs, and auto-reset thermal cut-outs.
; X1 ~$ \. T2 pIn applying the requirements of 4.15 and 12.7 the following notes are to be referred to:: _: f0 B3 i! F/ L X8 ]* g% j% D- }
NOTE 1 - ‘Fixing points’ means both the fixing points of components and the fixing points of a luminaire to the2 N# ^) v* p0 ? u
mounting surface.$ ]' a: t2 a2 M1 }5 T
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NOTE 2 - ‘Exposed part’ means the outer surface of the luminaire enclosure.4 F; _7 D0 Q. l6 Y2 p
NOTE 3 - Measurement of exposed parts is restricted to those parts providing the luminaire/component fixing or; c5 E9 p. C" u4 {' J
parts providing a protective barrier against accidental contact with live parts, as required by section 8 of this0 {5 ^# A8 D+ f* p. z: W
standard.2 j4 [6 B/ S' h6 P8 `1 @
NOTE 4 - The hottest part of the thermoplastic material section requiring test is measured. This may often be on
; J- V: q+ U' xthe internal surface of a luminaire enclosure not the outer surface.
- a( g* z' h% G5 e, X1 _& WNOTE 5 - The material temperature limits defined by clause 12.7 are with respect to materials under both
+ V6 M4 z9 R( Y& P4 hmechanical load and no mechanical load.
2 x8 n( R: [" L$ W% KNOTE 6 - The application of clause 12.7 must be read together with the requirements of sub-clause 4.15. |
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