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12.7 Thermal test in regard to fault conditions in lamp controlgear or electronic
/ u U# A" B1 r% G& i; Adevices in plastic luminaires
, D5 e$ G9 w) b6 R6 j( xThe test applies only to luminaires with a thermoplastic housing not fitted with an extra$ d" z" c6 B8 c. U: b/ x
mechanical temperature-independent device as per 4.15.2.3 y7 c' X! k+ |+ O9 {. Q" u z
# B! K( _ M/ [' L0 y- L12.7.1 Test for luminaires without temperature sensing controls
8 S4 d9 L E4 c$ r, a2 {, SThe luminaire shall be tested under the conditions specified in items a), c), e), f), h) and l) of" J" p4 Z: s8 g. l: F
12.4.1. In addition, the following also applies.
! f! V8 [& e/ `- ~20 % of the lamp circuits in the luminaire, and not less than one lamp circuit, shall be
4 A& B1 Y4 w& C0 jsubjected to abnormal conditions (see item a) of 12.5.1).
# P# }; ]) A/ [5 Q: l: X4 r' @The circuits which have the most thermal influence on the fixation point and exposed parts
+ n9 Y* ]4 i3 {shall be chosen and other lamp circuits shall be operated at rated voltage under normal
& }1 I: I1 e! d: Uconditions.
& J& Y2 y3 K4 Q8 C3 [, pThe circuits subjected to abnormal conditions shall be operated at 1,1 times (the rated voltage% R0 v0 Z4 w6 \' x, X% k# i/ s' l
or the maximum of the rated voltage range). When conditions are stable, the highest winding' L8 ?" T/ G5 s) d' g/ a+ d3 I: m2 F
temperature and highest temperature of fixing points and most thermally influenced exposed( v; s$ D0 Z$ O1 Y4 @4 R. w
parts shall be measured. It is not necessary to measure the temperature of small wound5 F$ V) z7 f* ]+ G& i: I3 b
devices that are incorporated within electronic circuits.' U! z, Z* e$ P" [4 g) V/ K1 G, m
Compliance& Z( T9 {5 L; S) X
The values of the ambient temperature and the temperature measured at 1,1 times (the rated' O+ C( P. z) w5 m* R0 h C: B6 m
voltage or the maximum of the voltage range) are used for the linear regression formula in
+ _* `4 V( p; U/ Fcalculating the temperature of fixing points and other exposed parts in relation to a1 f4 i Y2 j1 i( y- W. a% o
ballast/transformer winding temperature of 350 °C. The calculated value shall not exceed the
' u& ^7 i3 C) y$ J: _: jtemperature of the deflection under load of the material in accordance with method A as' p+ E8 E- F6 B' H, V! t
defined in ISO 75 (1987), Plastics and ebonite – Determination of temperature of deflection: h7 `, v- O% J
under load.6 D& {3 J5 P3 Q5 i+ ?0 w
12.7.2 Test for luminaires with temperature sensing controls internal/external to the. d9 k, D- o+ }5 W3 e
ballast or transformer+ J& a D2 v4 p% K1 n. J& Y, t
The luminaires shall be set up for this test as described in the first three paragraphs of 12.7.1.
) r: m& Z1 [- S2 E. d: [ \4 Y% q* L& s, j: V, l7 c
The circuits subjected to abnormal conditions shall be operated with a slowly and steadily3 M5 d9 V; d4 z3 j2 t" u" I' D
increasing current through the windings until the temperature sensing control operates.
' a" {4 K1 ?. U5 x7 X+ t7 bTime intervals and increments in current shall be such that thermal equilibrium between
7 x- |& e5 E3 L1 G2 Ewinding temperatures and temperature of fixing points and most thermally influenced exposed0 a0 m" Z% n, [, d) S' ~5 D: a
parts is achieved as far as is practicable. During the test, the highest temperature of the spots
( n8 ^7 c' y: t7 Z, _: D! @4 y* ttested shall be continuously measured.
- T1 A/ A ?8 w+ iFor luminaires fitted out with manual-reset thermal cut-outs, the test shall be repeated six
; W1 D+ S' ]! `# |times allowing 30 min intervals between tests. At the end of each 30 min interval, the cut-out: H; ?9 D j( @) o/ j d/ V
shall be reset.2 ]' O' A2 Z4 ~ F# W
For luminaires fitted out with auto-reset thermal cut-outs, the tests shall be continued until a4 A4 H" c; e" r0 e) M
stable temperature is achieved.
! T9 o5 |- \. O' A6 ?; W# l% l/ c5 i8 I( iCompliance) M; p$ O* c6 O
The highest temperature of the fixing points and most thermally influenced exposed parts,$ i+ b" _1 |. m+ M) B5 j2 ^
shall not exceed the temperature of deflection under load of the material according to the" n; J6 K7 C: S- ^1 {; }
method A as defined in ISO 75, at any time during the tests for thermal links, manual-reset
# y' w5 o2 L% w: w+ `2 z- {% o nthermal cut-outs, and auto-reset thermal cut-outs.
+ _4 P/ g& b5 C; q- o. z( S ~In applying the requirements of 4.15 and 12.7 the following notes are to be referred to:8 y0 F0 o+ a5 d& @! h
NOTE 1 - ‘Fixing points’ means both the fixing points of components and the fixing points of a luminaire to the- h$ ~0 C1 V3 z2 f/ C2 r, o+ {
mounting surface.$ v5 t$ ~4 h- h
" u. W5 o* a3 D* M
NOTE 2 - ‘Exposed part’ means the outer surface of the luminaire enclosure.
) I& {, \$ L# N/ GNOTE 3 - Measurement of exposed parts is restricted to those parts providing the luminaire/component fixing or% d; { {5 A% N: @
parts providing a protective barrier against accidental contact with live parts, as required by section 8 of this/ C3 P4 s7 [8 Y q1 A: q
standard.! Z7 s! E, e* R' r
NOTE 4 - The hottest part of the thermoplastic material section requiring test is measured. This may often be on
# q' e9 ~- B! i# Z* xthe internal surface of a luminaire enclosure not the outer surface.9 r2 h( c- d8 G# c
NOTE 5 - The material temperature limits defined by clause 12.7 are with respect to materials under both( T' u1 I& t6 c, N
mechanical load and no mechanical load.
, p6 V8 o, a; f% c3 B2 H8 DNOTE 6 - The application of clause 12.7 must be read together with the requirements of sub-clause 4.15. |
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