Instruction manual

17
• Parallel circuit of lamps operated with multi-lamp ECG ≠in general
single-lamp operation possible
• Parallel circuit of lamps, but no single-lamp operation possible because
for example
- the sum of electrodes has to be recognized
For twin- and multi-lamp ECG the question is whether the remaining lamps
will continue to operate if one lamp is defect or has been removed.
In the case of twin- or multi-lamp ECG, any lamp fault that causes the safe
shutdown circuit to operate will lead to the shutdown of all lamps.
This function is called “safety shutdown”. The detection of various “out-of-
range” parameters results in a reliable shutdown of the ECG. The ECG do
not perform any lamp starts that could cause problems as described under
chapter 2.3.
In this case, one lamp or the remaining lamps will therefore never continue
to burn by itself.
What happens when one lamp is removed from a multi-lamp ECG will
depend on the type of circuit. Series circuits always exclude a single-lamp
operation. Parallel circuit is one condition for a possible single-lamp
operation, however, not the only one. Another important criterion is lamp
control during operation of circuit related as well as safety related data.
QUICKTRONIC
®
INTELLIGENT, QTi, are carried out in parallel circuits, but
cannot be operated in single-lamp mode. The reason is the sophisticated
lamp detection requiring the control of various parameters.
The following table gives a short summary of the different ECG-types:
ECG-type
height
QTi
21 mm
QT-FH
30 mm
QT-FQ
30 mm
QT-FH 3x, 4x
30 mm
QT … F/CW
21 mm
Series circuit X X X X
Parallel circuit. X
For all types shown in the table above a single-lamp operation is not
possible.
2.7 Noise
T5/∅ 16 mm-fluorescent lamps FH
®
…HE, FQ
®
…HO and FC
®
operated
at high frequency with QUICKTRONIC
®
control gear are virtually
silent.
QUICKTRONIC
®
units themselves are so quiet that even in very quiet
surroundings they cannot be heard by the human ear. They are
therefore ideal for sound-sensitive areas such as radio and recording
studios. The limit of the frequency-dependant sound pressure curve
is based on the audibility threshold (in other words, a person with
normal hearing will not be able to detect the noise generated by an
ECG in the same room).
The factors affecting the sound pressure level are the sound power level of
the ECG, the absorption properties of the room, characterised by its volume
and reverberation time, and the number of ECGs.
In mains supplies with a high level of distortion in which the mains voltage
wave form deviates significantly from a sine wave, a „chirping“ may be
heard from the reactance coils in the input section of the ECG.