Operating instructions for Cable Detector, article 37270766
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4.
Measuring procedure
4.1
Safety procedures during measuring
1.
Connecting the transmitter to the grid supply can generate a current of a few milliamperes in the
circuit in live condition; accordingly, the transmitter can be grounded only on a neutral conductor. If
the transmitter connection is from the phase to the protective conductor, the functional safety of the
protective conductor must first be tested per DIN VDE 0100. Because all components connected to
ground are then connected to ground by the transmitter with the phase, meaning that they can
become live in the event of a fault (if the grounding resistance is not in accordance with
requirements).
2.
If the transmitter is connected to a live grid and the ground connection of the transmitter is connected
to a ground phase, the fault current (if present) in the power supply line can combine with the current
in the transmitter circuit to trip the fault-current circuit breaker i.e. trigger FI/RCD.
1.
When using the transmitter as a voltmeter to test grid voltage, there is often a small spark when the
measurement sensor touches grid voltage. This is a normal reaction.
2.
If the Start/Stop, Code Set or Level Set key is active, the other two are inactive.
3.
If the receiver is operating in automatic mode, it can be switched to manual mode or grid voltage
ident mode at any time; if the receiver is set to manual mode, the UAC or MANUAL key is reactivated
only after leaving manual mode.
4.2
Functional principle
This cable detector is portable and consists of a transmitter, receiver and some accessory components. To locate a
cable (or metal pipe) the transmitter sends an alternating voltage modulated by digital signals. This voltage
generates an alternating field (see Fig. 2-1). If you hold the sensor of the receiver near the field, the sensor
generates an induced voltage. This device amplifies this weak voltage signal several hundred times, and then based
on the signal changes, and after decoding the audio frequency, demodulation and digital processing, shows the
position of hidden cables and pipes as well as their defects on an LCD screen.
1.
For all applications the transmitter connections must form a closed circuit.
2.
This cable detector can only detect and locate lines that are connected correctly per the described
physical principles.
