21
ABB i-bus
®
KNX
Functional description
In the case of lamps filled with gas, a burn-in time is recommended as
solid or fluid additives in them must be evaporated before optimum
operation can be achieved and an optimum internal pressure in the lamp is
enabled. This burn-in process is only necessary once before the start of the
commissioning process.
Only after this burn-in time do fluorescent lamps have a stable operating
value which ensures the best possible dimming behaviour and an optimum
service life. An optimum pressure level is created in the fluorescent tube.
For installations with dimmable ballasts, many lamp manufacturers give the
recommendation that a burn-in time of 20 – 100 hours must be observed.
The recommended values are 20 hours for T8 lamps and 100 hours for T5
lamps. During the burn-in time, the lamps are only switched on at maximum
capacity. Dimming is not possible.
The information about burn-in times can often not be found in the catalogue
of the lamp manufacturer but in the descriptions of the electronic ballasts.
The reason for this is that the burn-in time is only relevant for dimmable
installations. Stable operating values and reproducible brightness values
are a prerequisite in these installations. Moreover, only poor evaporation of
the solid or fluid additives is possible for dimmed lamps due to the reduced
capacity so that in certain circumstances the maximum light yield is only
achieved at a later date or not at all.
This can lead to the complete replacement of the lamps.
According to statements of lighting planners, if fluorescent lamps (particu-
larly T5 lamps) are not burned in, they can even be damaged which causes
them to fail earlier.
3.8 Burn-in
times
