Manual

tams elektronik
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LD-G-43 tams elektronik
Reaction to an overvoltage pulse
In analogue AC systems, interference voltages from the system can be interpreted by the
decoder as a changeover pulse for changing the direction of travel. The sensitivity with which
the decoder reacts to an overvoltage pulse with a change of driving direction can be set in a
CV.
2.3. Overload protection
The locomotive decoder LD-G-43 has an overload protection which protects it from damage in
case of exceeding the permissible total current or a short circuit at the motor output (the
maximum form of an overload). If an overload is detected, the motor is switched off and
lights that are switched with F0f or F0r flash. Resumption of operation is only possible after
the decoder has been de-energised (track voltage off).
The response threshold of the overload protection can be adjusted by change in sensitivity,
i.e. the magnitude of the overload at which the overload is detected ("short-circuit
sensitivity").
Overload at an output
In case of a short-circuit at one output or if the maximum current at one of the outputs is
exceeded, the overload protection of the decoder is ineffective as long as the total current of
the decoder is not also exceeded. The output in question will be damaged.
Attention:
By lowering the overload response threshold, the influence of short-term interference
voltages from the motor or connected consumers is to be reduced. This prevents the motor
from being switched off although the permissible total current has not been exceeded.
Before lowering the response threshold, the motor current must always be measured and
the proper functioning of the motor and the gear unit checked.
Attention:
When a short circuit occurs that bypasses components on the decoder either to each other
or to track voltage, the overload protection is not effective.
Examples:
 contact between the decoder and the rails or metal parts of the vehicle;
 contact between not-isolated decoder connecting wires and the rails or metal parts of
the vehicle;
 contact between accessories connected to the common return conductor of the decoder
and the rails or metal parts of the vehicle.
Attention:
Malfunctions of the locomotive motor (e.g. the so-called "sparking of the brushes") can
cause extreme interference current, possibly damaging components on the decoder. The
decoder´s overload protection is without effect with this extremely high current.
10 | Operation overview