OSRAM QUICKTRONIC-M ECG for circular FL 16 mm - Manual (Page 45)

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At significantly lower or higher cold-spot temperatures than the specified
temperature the electrical properties of the lamps change drastically and
there is a significant reduction in luminous flux.
In normal cases of significant deviations, the shutdown mechanism in the
ECG will operate. In extreme cases there may be damage to the electronic
control gear.
If the lamp temperature is too low it may be difficult to start and the
luminous flux may be too low. Selecting a different site for installation
generally helps, or using some kind of outer tube to conserve the heat of
the lamp. It is important that this outer tube is installed on the etched lamp
side around the electrode (cold spot). In any case, we recommend that
luminaire manufacturer informs the electrician by printing the information
on the inside of the luminaire.
If the ambient temperatures are too high the ECG can be damaged and the
light output is too low. An optimized cooling is necessary.
In order to avoid a thermal interference when operating a multi-lamp T5-
system, it is required to install the lamps always with the lamp etch on one
side.
3.9.4 General
Recommendations for
Installation
It is important to ensure that the lamp and the ECG are positioned in the
luminaire so that they do not mutually heat one another and that the ECG
power loss can be properly dissipated even at the maximum expected
ambient temperature and/or supply voltage.
The tc-temperature at the measuring point on the ECG must not be
exceeded during operation even at the maximum expected ambient
temperature and/or supply voltage. Under “normal” ambient conditions the
tc-temperature measured at the measuring point should be at least 5 °C to
10 °C below the specified maximum value so there is a safety margin to
allow for extreme situations.
It may be necessary to split lamp and ECG (with, say, the lamp in the
luminaire and the ECG in the stand or luminaire support) such that the
absence of special measures the lamp and the ECG would not mutually
heat each other if arranged in close proximity, leading to excessive
temperatures of the lamps and/or the ECG. In such arrangements ensure
that the maximum cable length between ECG and lamp(s) is not exceeded
and the wiring instructions under Section
4.1 and 7.1 are followed.
3.9.5 Measuring the
Temperature
The simplest way to measure the relevant temperatures on the lamp
(especially at the cold-spot) and on the ECG (tc point) is with
thermocouples fixed to the lamp/ECG and a suitable measuring instrument.
Make sure the adhesive used is neutral in terms of its thermal, electrical
and photometric properties.
To measure the ECG temperature it is convenient to have a thermocouple
permanently attached to a housing cover and to exchange this for the
original cover.
The temperature values should only be measured when the steady-stae
temperature has been reached (in other words, when there has been no