Indoor Furnishings User Manual

2000-11-07
6
2.5.3 ‘TL’5 lamps and cold conditions
If the ambient temperature within the luminaire is lower than the
optimum temperature of 35 °C for ‘TL’5 lamps,due to “cold”
applications (outdoor,cooling rooms,etc.) One solution is to cover
the cold spot with an insulating cap to reach optimum light output.
2.5.4 Vertical burning position
As mentioned before the optimum light output with ‘TL’5 lamps is
reached at 35 °C in draught-free air with the lamp in horizontal
position.If the lamp is operated in vertical position the upper lamp
side will be heated to a slightly higher temperature than the lower
lamp side.
So with vertical burning of the lamp at cool ambient temperatures
the stamp side with the cold spot should be in the top. At warm
ambient temperatures the stamp side should be at the bottom.
2.5.5 ‘TL’5 lamps and twin-lampholders
If ’TL’5 lamps are operated in so-called twin-lampholders,the hot
spots near the electrodes could influence the burning conditions of
the combination too.Therefore for a proper lamp operation it is
recommended to mount both lamps with the cold chamber (lamp
stamp end) at the same side.
If T
amb
is low and so the ambient conditions require heating the
cold chamber (see 2.5.2,2.5.3 and 2.5.4) anti-parallel mounting of
the lamps could help in that respect.In that case the electrode
opposite to the cold chamber of one lamp will heat the cold
chamber of the other lamp.
2.6 General recommendations for
handling and measuring ‘TL’5 lamps
and luminaires
• Handling
Always handle a ‘TL’5 lamp as much as possible in vertical posi-
tion,with the stamp at the lowest side:during transport, putting it
in a measuring system,putting it in a luminaire,etc. in order to
keep the mercury as much as possible in the cold spot.
• Measuring luminaires for ‘TL’5 lamps
Before measuring the light output ratio of a luminaire the ‘TL’5
lamps should be in stable condition:the liquid mercury must be in
the cold chamber.To reach this condition the following steps
should be taken:
1. For bringing the lamps in a stable condition season the lamps
for approximately 100 hours vertically with the cold chamber
(located at stamped side) at the lowest point.
2. When the lamps have been off for more than 12 hours burn
the lamp for at least 4 hours in the above described position
before measuring.
Transport the lamp in vertical position with the cold chamber
at the lowest point to the measuring system.
Gently put the lamp in the (horizontal) lampholder,taking care
that during installing the lamp the cold chamber stays as much
as possible at the lowest point.
3. For bringing the lamp again in a stable condition burn the lamp
on the nominal ballast for 1 hour at 25 ºC and check stability
(see Note below) by monitoring the luminous flux.
4. Measure the luminous flux of the lamp with the nominal
ballast at 25 ºC.
5. Gently put the lamp and ballast in the luminaire under test
(take care that the cold chamber stays as much as possible at
the lowest point) and burn the lamp for at least 1 hour at
25 ºC and check stability again by monitoring the luminous
flux.
6. Measure the luminous flux of the luminaire at 25 ºC ambient
temperature.
Note: For an additional check if the lamp is stable one can cool
down locally (by air flow,cold spray ........) the cold chamber.
If the light output drops fast,following the cooling of the cold
chamber,the lamp was stable (i.e. the mercury vapour
pressure is controlled by the cold chamber).If this test is
performed the lamp has to burn in a stable manner for at
least 15 minutes before starting the actual measurement.
2.7 Lampholder/lamp cap
Lampholders and wiring for ‘TL’5 lamps should be the 500 V rated
versions.
The existing lampholders for G5 capped lamps are suitable up to
250 volt,which means that the applied voltage must be lower than
250 volt towards earth.As ‘TL’5 lamps are especially designed for
operation with electronic gear (High Frequency operation),the
voltage may exceed 250 volt under dimming conditions.
Several lampholder manufacturers have G5 lampholders in their
range which are 500 V marked,which means that voltages up to
500 volt towards earth are allowed.
In principle, all requirements relating to G5 type lampholders will
be summarized in IEC Publications 60061-2,60061-4 and 400.
G5 lampholders rated for 250 V continuous voltage are not
released to operate with ‘TL’5 lamps.
2.8 Misuse with ‘TL’5 lamps
According to IEC regulations luminaire/ballast systems should be
designed in such a way that cap temperatures exceeding 120 °C are
prevented (see also 2.4.2).
Replacing ‘TL’5 lamps with the wrong type with the same length will
seldom lead to unwanted situations during normal operating condi-
tions.However, accidental exchange of ‘TL’5 lamps with the wrong
type in abnormal,high temperature conditions might lead to over-
heating of the the lamp caps.Therefore for luminaire manufacturers
it is advised to mark clearly which lamp the luminaire is aimed for.