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12.7 Thermal test in regard to fault conditions in lamp controlgear or electronic
: @/ }% ~% k5 L! Hdevices in plastic luminaires) U( H; z H( C8 f6 ?! J% `& w9 L
The test applies only to luminaires with a thermoplastic housing not fitted with an extra
, \$ x. \; [ m% A5 z5 `) X mmechanical temperature-independent device as per 4.15.2.3 _# u9 H9 ~& T( P* v1 u% W
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12.7.1 Test for luminaires without temperature sensing controls0 c! X* w. g0 x- d/ I/ w) M) p
The luminaire shall be tested under the conditions specified in items a), c), e), f), h) and l) of: r) R- O( K( n# F2 U. U3 w0 \* v6 j: R
12.4.1. In addition, the following also applies.
: e5 X5 U- R5 }3 F* F" K: d& K20 % of the lamp circuits in the luminaire, and not less than one lamp circuit, shall be5 D. c! |9 b& o. m: j+ P
subjected to abnormal conditions (see item a) of 12.5.1).
0 S! b5 |2 e/ i, ]The circuits which have the most thermal influence on the fixation point and exposed parts
1 F1 [6 E$ w3 j2 Dshall be chosen and other lamp circuits shall be operated at rated voltage under normal
) }( L5 r. M; H. E3 A' d' T) w) `conditions.
' F9 \1 x; i l: KThe circuits subjected to abnormal conditions shall be operated at 1,1 times (the rated voltage) K' E, p. J5 a( `3 ]
or the maximum of the rated voltage range). When conditions are stable, the highest winding
/ h- d9 u* R( Y# x$ [; q+ h/ ?temperature and highest temperature of fixing points and most thermally influenced exposed
6 M/ c1 F9 X7 A8 Y/ \; Sparts shall be measured. It is not necessary to measure the temperature of small wound
: t* u2 s$ g# A0 }! E. n1 wdevices that are incorporated within electronic circuits." r5 m4 C3 Q& k( K, x h6 _7 H
Compliance
/ a0 ] ]; n* XThe values of the ambient temperature and the temperature measured at 1,1 times (the rated+ C1 ^9 f8 L) x3 E Q
voltage or the maximum of the voltage range) are used for the linear regression formula in& e- ?* w7 `( n$ g
calculating the temperature of fixing points and other exposed parts in relation to a w4 s0 o6 R( b
ballast/transformer winding temperature of 350 °C. The calculated value shall not exceed the
, L3 @. d D" U) Dtemperature of the deflection under load of the material in accordance with method A as+ ~, C8 W5 G6 Z( j6 l& s
defined in ISO 75 (1987), Plastics and ebonite – Determination of temperature of deflection* B8 l+ U3 }3 A5 t- x7 e4 Z6 z
under load.
" }( U! D" {+ Q0 j w+ U/ W' W12.7.2 Test for luminaires with temperature sensing controls internal/external to the( S! ~3 j. m# A' b
ballast or transformer
3 D4 L& S7 R* @6 D$ h! X6 zThe luminaires shall be set up for this test as described in the first three paragraphs of 12.7.1.. I/ c2 J0 p9 ~2 u7 b0 ^4 T
) r* {' G. d* L% v; `) s& }
The circuits subjected to abnormal conditions shall be operated with a slowly and steadily: ?1 M: X$ k) q+ `. Z
increasing current through the windings until the temperature sensing control operates.
7 J& e+ G5 |1 J* VTime intervals and increments in current shall be such that thermal equilibrium between
h* F& _+ m! ?: I# V' bwinding temperatures and temperature of fixing points and most thermally influenced exposed/ X0 Y/ Q7 S q% ?1 E7 D. @4 V
parts is achieved as far as is practicable. During the test, the highest temperature of the spots+ [ q2 |: z2 g# c" k
tested shall be continuously measured.
- Q; D; i- t# e# b$ R. S* }For luminaires fitted out with manual-reset thermal cut-outs, the test shall be repeated six$ }$ h5 o8 c7 }, {/ {" L
times allowing 30 min intervals between tests. At the end of each 30 min interval, the cut-out8 W; ~' \1 T( d" R- i6 ?8 }( c
shall be reset.
( h$ ]: S+ _5 n$ d* ^3 q5 W3 \For luminaires fitted out with auto-reset thermal cut-outs, the tests shall be continued until a# u: g# ^, l1 A& j! V
stable temperature is achieved.
( N& i/ `; u' D" }+ }Compliance
4 @' ^; z7 d; A/ o. lThe highest temperature of the fixing points and most thermally influenced exposed parts,
+ y" Y2 W: o" x( j2 S2 yshall not exceed the temperature of deflection under load of the material according to the0 T7 _- k3 C; V, q
method A as defined in ISO 75, at any time during the tests for thermal links, manual-reset+ R$ @: Z- l& u/ O2 {
thermal cut-outs, and auto-reset thermal cut-outs.& M5 f" c: D* P' \
In applying the requirements of 4.15 and 12.7 the following notes are to be referred to:# n+ L" w9 |# ^4 Q/ F7 Y9 m
NOTE 1 - ‘Fixing points’ means both the fixing points of components and the fixing points of a luminaire to the
) M) R# N" e. l0 [+ hmounting surface.& U `5 P" P7 |6 K: E) r
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NOTE 2 - ‘Exposed part’ means the outer surface of the luminaire enclosure.
# T& }3 H/ ]% Y, G0 BNOTE 3 - Measurement of exposed parts is restricted to those parts providing the luminaire/component fixing or
& Q9 g. _' X0 b: E# V% t" Eparts providing a protective barrier against accidental contact with live parts, as required by section 8 of this
0 I+ _+ N2 Q$ w: `" u [8 C- ~3 s" xstandard.$ r8 S2 w9 {% k6 |' F
NOTE 4 - The hottest part of the thermoplastic material section requiring test is measured. This may often be on) h- T' F- Y& ]* `
the internal surface of a luminaire enclosure not the outer surface.
# l5 }' P- m! c2 V5 \/ DNOTE 5 - The material temperature limits defined by clause 12.7 are with respect to materials under both
3 V4 L' W- L) N6 O$ [7 Nmechanical load and no mechanical load.5 f1 k) S6 T: b; P
NOTE 6 - The application of clause 12.7 must be read together with the requirements of sub-clause 4.15. |
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