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12.7 Thermal test in regard to fault conditions in lamp controlgear or electronic
7 f h6 G' e8 Q; p/ M' m0 f$ W5 adevices in plastic luminaires @" J0 a8 d+ ]; r- O0 T+ d
The test applies only to luminaires with a thermoplastic housing not fitted with an extra" {5 o# ^1 Z' H; T( c) A* |& ?1 J( D- E
mechanical temperature-independent device as per 4.15.2.: }# A' t, _# D8 c5 M0 W& S; g; I' u
# n3 Z) J3 h6 _; m12.7.1 Test for luminaires without temperature sensing controls
0 z7 [: R6 k' \. s8 hThe luminaire shall be tested under the conditions specified in items a), c), e), f), h) and l) of& Q/ y$ q: e* _! t6 v' c' H
12.4.1. In addition, the following also applies.- v" n; v+ s0 H# K
20 % of the lamp circuits in the luminaire, and not less than one lamp circuit, shall be8 s5 W. t9 w v# _0 G. U, x% i
subjected to abnormal conditions (see item a) of 12.5.1).
5 k7 z k) ^0 k7 L, @6 s# Y& qThe circuits which have the most thermal influence on the fixation point and exposed parts( a( E/ }+ i x' {9 P
shall be chosen and other lamp circuits shall be operated at rated voltage under normal d( s6 T5 J. i( S# l7 P4 A5 `& q$ f* a
conditions.8 y- u$ l1 S& b" e! x; h
The circuits subjected to abnormal conditions shall be operated at 1,1 times (the rated voltage
/ z7 ]. p! x8 B- o- }8 wor the maximum of the rated voltage range). When conditions are stable, the highest winding8 B6 G" r N0 F* e
temperature and highest temperature of fixing points and most thermally influenced exposed# C% A8 W/ A6 F: w9 I$ D
parts shall be measured. It is not necessary to measure the temperature of small wound4 H5 x3 \( @% {& r$ c
devices that are incorporated within electronic circuits." q5 Q) ^- |9 `8 @' q( Y( s
Compliance! G; o/ A9 q& L3 ?% Y& F
The values of the ambient temperature and the temperature measured at 1,1 times (the rated7 b: c- @% q# c7 G( r
voltage or the maximum of the voltage range) are used for the linear regression formula in( @1 D @" G& {: N9 w
calculating the temperature of fixing points and other exposed parts in relation to a- x# j6 K: r$ a' j2 \" J
ballast/transformer winding temperature of 350 °C. The calculated value shall not exceed the* ], T5 J9 q' |
temperature of the deflection under load of the material in accordance with method A as
$ M( z7 ?" F: s) Jdefined in ISO 75 (1987), Plastics and ebonite – Determination of temperature of deflection- z6 x3 O" ^+ [& Z* J
under load.( M ^6 n% {. g, _* r; k$ c
12.7.2 Test for luminaires with temperature sensing controls internal/external to the( H% q& E; e" B) n i
ballast or transformer
# k6 j- g& [3 W) u1 z4 `The luminaires shall be set up for this test as described in the first three paragraphs of 12.7.1.
5 ^' H+ ~4 G0 K1 r% D' Q
3 i+ n5 ^0 J# v d# N+ ~9 R7 }The circuits subjected to abnormal conditions shall be operated with a slowly and steadily
- v* U! `: v( uincreasing current through the windings until the temperature sensing control operates.
, s% K: ~6 K- b/ D0 f4 }! C9 sTime intervals and increments in current shall be such that thermal equilibrium between
3 V+ F3 F3 G; mwinding temperatures and temperature of fixing points and most thermally influenced exposed4 h9 A7 h* t5 E; t0 @9 x& I
parts is achieved as far as is practicable. During the test, the highest temperature of the spots* S$ w+ N" o4 h3 F0 P' C0 B
tested shall be continuously measured.: t% p1 Y/ [* i3 }5 T
For luminaires fitted out with manual-reset thermal cut-outs, the test shall be repeated six
. e9 o5 \/ V4 Atimes allowing 30 min intervals between tests. At the end of each 30 min interval, the cut-out
& G# L3 k: e: R& R1 p6 q* Vshall be reset.
; {) J* {( I- D5 f# o' P/ V. {3 oFor luminaires fitted out with auto-reset thermal cut-outs, the tests shall be continued until a
- c3 B4 q* `- \+ m1 Istable temperature is achieved.
2 |2 k- Q# t7 `; u# \4 \7 \Compliance
+ r3 R" k" x0 _/ w @" lThe highest temperature of the fixing points and most thermally influenced exposed parts,+ P% K e$ m( {* m* f. Z
shall not exceed the temperature of deflection under load of the material according to the
! F( S& Q. Q4 r+ T4 k0 z; L fmethod A as defined in ISO 75, at any time during the tests for thermal links, manual-reset; w U+ g% s- k' O9 X* H- o
thermal cut-outs, and auto-reset thermal cut-outs.
0 @* u! u. m/ i& y, r+ k j9 vIn applying the requirements of 4.15 and 12.7 the following notes are to be referred to:" c" ]7 @0 @$ }2 a4 {
NOTE 1 - ‘Fixing points’ means both the fixing points of components and the fixing points of a luminaire to the
( G" O9 W: [/ _. L! a6 I+ Wmounting surface.' w9 b, k6 u; d# p
6 m* @' {+ \ X6 Q: L2 o) B) d6 ENOTE 2 - ‘Exposed part’ means the outer surface of the luminaire enclosure.+ S3 k. `: H) @) o3 p
NOTE 3 - Measurement of exposed parts is restricted to those parts providing the luminaire/component fixing or
$ w. F7 H1 f" g" R( \8 ]! ^parts providing a protective barrier against accidental contact with live parts, as required by section 8 of this
g S7 d7 h* b' Y: V# A' kstandard.
! c! C: i, Z8 B1 R4 j, Y2 t- I8 QNOTE 4 - The hottest part of the thermoplastic material section requiring test is measured. This may often be on
! |! M& |/ ?% m' {0 J/ Bthe internal surface of a luminaire enclosure not the outer surface.
9 ~0 ?4 ]( P( j& }NOTE 5 - The material temperature limits defined by clause 12.7 are with respect to materials under both
- \6 e' w7 K3 F- Q. `: ~mechanical load and no mechanical load., f1 p! l% _9 g) o
NOTE 6 - The application of clause 12.7 must be read together with the requirements of sub-clause 4.15. |
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