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12.7 Thermal test in regard to fault conditions in lamp controlgear or electronic
T1 i0 c/ v& [; z6 o- ldevices in plastic luminaires; w2 s" f6 H# F& A
The test applies only to luminaires with a thermoplastic housing not fitted with an extra
9 V# O( D( C$ Cmechanical temperature-independent device as per 4.15.2.
5 n; {- x- p2 R" W( K/ N2 q. M' U+ E1 ^5 n
12.7.1 Test for luminaires without temperature sensing controls1 O: G* b' ?9 k% u* C3 _8 A
The luminaire shall be tested under the conditions specified in items a), c), e), f), h) and l) of, E$ G4 x5 n5 \0 ]) P
12.4.1. In addition, the following also applies.
/ ]# w8 {) t% J5 P0 {: d& U8 f7 e7 K20 % of the lamp circuits in the luminaire, and not less than one lamp circuit, shall be
6 v( D% C W2 i8 J, A! q. U+ C/ a5 Csubjected to abnormal conditions (see item a) of 12.5.1).
: F: Z5 G$ V: _6 K9 j ~ hThe circuits which have the most thermal influence on the fixation point and exposed parts
. `" X5 L: G3 |2 m; j. Zshall be chosen and other lamp circuits shall be operated at rated voltage under normal
' u2 @) c! y* X- R( ^conditions.2 ^* Z: n0 k7 P% a; r5 R7 `
The circuits subjected to abnormal conditions shall be operated at 1,1 times (the rated voltage1 B3 w) [, K( ~" h) p3 D/ n
or the maximum of the rated voltage range). When conditions are stable, the highest winding }& |$ B, E; N
temperature and highest temperature of fixing points and most thermally influenced exposed
1 N( g, T% m: s1 Aparts shall be measured. It is not necessary to measure the temperature of small wound! S2 h- E0 n, c5 f" B8 y
devices that are incorporated within electronic circuits.5 j# p, d) @" H" E) G
Compliance
; H) y7 f) g! o+ c% h1 n! E: ^The values of the ambient temperature and the temperature measured at 1,1 times (the rated# @. n7 p% W _5 r0 k# u8 j
voltage or the maximum of the voltage range) are used for the linear regression formula in
0 {! P$ N% r: Z% k7 F9 A- V: ecalculating the temperature of fixing points and other exposed parts in relation to a2 I' ]3 n" t& v- f" j/ r
ballast/transformer winding temperature of 350 °C. The calculated value shall not exceed the
: T, E# ]1 \+ }. _5 x/ b9 vtemperature of the deflection under load of the material in accordance with method A as
) t* u! q$ A0 r% J+ _ sdefined in ISO 75 (1987), Plastics and ebonite – Determination of temperature of deflection% F/ f. N& n+ r2 o$ h3 }- Y
under load.
" u5 v* O- F' g3 g12.7.2 Test for luminaires with temperature sensing controls internal/external to the
9 Z# a5 j: B4 T" E4 Z2 }+ D# Sballast or transformer
. s0 {( o& ]' I) ^/ C3 I: Y& T8 bThe luminaires shall be set up for this test as described in the first three paragraphs of 12.7.1.
6 |/ t- B- C# }/ |, g9 \0 F7 K, ]9 Y5 T. ?& M0 Z% W5 V4 f
The circuits subjected to abnormal conditions shall be operated with a slowly and steadily
' m# b# q$ D2 A0 X0 e8 {/ Lincreasing current through the windings until the temperature sensing control operates.
3 B, {6 n9 A6 ~8 u7 P$ GTime intervals and increments in current shall be such that thermal equilibrium between
' v( f1 y: T8 p; R4 Y+ ^winding temperatures and temperature of fixing points and most thermally influenced exposed
6 _6 o' E" y( R9 `; H( Sparts is achieved as far as is practicable. During the test, the highest temperature of the spots
- `1 [! K4 p. K' atested shall be continuously measured.7 F- }) c9 b# d3 l: b6 q
For luminaires fitted out with manual-reset thermal cut-outs, the test shall be repeated six
& S0 L. w4 a# Xtimes allowing 30 min intervals between tests. At the end of each 30 min interval, the cut-out" r5 _2 @: s" |% |: _
shall be reset./ P4 L# V3 t% r$ k7 W" g$ ^
For luminaires fitted out with auto-reset thermal cut-outs, the tests shall be continued until a
4 K( l5 R* B" cstable temperature is achieved.
* M$ d/ d" l. E+ k: o7 tCompliance' k3 R8 k, O2 f! N0 z1 C
The highest temperature of the fixing points and most thermally influenced exposed parts,% [; f9 I7 ^' K4 Z
shall not exceed the temperature of deflection under load of the material according to the
! d! N9 e: b# {. Gmethod A as defined in ISO 75, at any time during the tests for thermal links, manual-reset
$ }- [) q1 n: i5 Q% |. N0 @thermal cut-outs, and auto-reset thermal cut-outs.
9 t+ [' r# _7 Q) M3 D( d/ TIn applying the requirements of 4.15 and 12.7 the following notes are to be referred to:
1 k( s& V* Y- v/ j9 }NOTE 1 - ‘Fixing points’ means both the fixing points of components and the fixing points of a luminaire to the
3 [5 T6 `4 r7 j; N) Gmounting surface.
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9 k% O! v5 C8 ^5 vNOTE 2 - ‘Exposed part’ means the outer surface of the luminaire enclosure.
3 b, M0 k, Z |4 `0 kNOTE 3 - Measurement of exposed parts is restricted to those parts providing the luminaire/component fixing or& m' H6 @$ p$ C
parts providing a protective barrier against accidental contact with live parts, as required by section 8 of this
$ D- x; W P" n1 w$ cstandard.
p: N& X3 E. dNOTE 4 - The hottest part of the thermoplastic material section requiring test is measured. This may often be on
4 X% [+ `7 ~3 A, W4 K) jthe internal surface of a luminaire enclosure not the outer surface.7 \4 D! K& r& z Z% F9 C7 h
NOTE 5 - The material temperature limits defined by clause 12.7 are with respect to materials under both2 U( l, ` m. ^% F
mechanical load and no mechanical load.8 r" J+ |8 D& F8 V
NOTE 6 - The application of clause 12.7 must be read together with the requirements of sub-clause 4.15. |
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