9
METRAFUSE FD PRO
Gossen Metrawatt GmbH
5
Operation
The METRAFUSE FD PRO is used for the speedy identification of which fuse or circuit
breaker is protecting a circuit.
5.1
Principle of Use and Advice for Best Performance
The METRAFUSE FD PRO consists of two parts: a receiver and a transmitter.
The transmitter is connected to the circuit under test and uses the circuit‘s power supply to
generate and inject a modified high frequency signal into the live conductor that can be
detected by the receiver.
Note!
The signal will not adversely affect other equipment but is powerful enough to work
over cable runs of several hundred meters.
The receiver uses a ferrite transducer to detect the signal from the transmitter at the distribu-
tion board. When its scanning tip is put in contact with the fuse or circuit breaker that is con-
nected to the circuit under test, it will indicate the presence of the transmitter signal both by
LED and beeping. Varying the angle at which the scanning tip is held in relation to the
breaker will affect the strength of the signal received. Therefore, for the duration of the test
you must keep the scanning tip at the same angle relative to the fuses or circuit breakers and
at a similar distance to them.
The signal strength indicator is comparative rather than absolute: Each press of the on/reset
button resets the sensitivity to maximum and the receiver will respond when placed in close
proximity to any fuse, circuit breaker or cable carrying the signal. During a test, the receiver
will auto tune its sensitivity to the strongest signal encountered since the reset button was
last pushed. It is therefore necessary to ensure that all of the breakers that could be protect-
ing a circuit are scanned at least twice and that you do not stop as soon as a maximum
strength signal is indicated.
Due to the differing designs of circuit breakers, it may sometimes be unclear which of two
circuit breakers the strongest signal comes from. Particularly if the maximum strength signal
appears to come from a boundary area between two adjacent circuit breakers. In this case,
rotate the receiver (without resetting) through 360º to identify the orientation in which the
strongest signal is found. Reset and re-scan the row of breakers. Alternatively, you can reset
the receiver (
8) and test at the opposite (to the common boundary) edge of each circuit
breaker. The strongest signal should come from the correct circuit breaker.
5.2
Finding Fuses or Circuit Breakers
The receiver‘s battery is full
The pre-use-check was positive
1. Connect the provided transmitter mains lead cable to the transmitter‘s mains cable and
test probe connector.
2. Plug the transmitter mains lead cable into an outlet of the circuit under test.
The transmitter is provided with power (the transmitter on LED is lit red). It automatically
injects the test signal into the live conductor.
