DEVItector™ II V2
User Guide
BC421332622232en-010101
2022.07 | FEC | ©Danfoss | 5
4. The equipment
The DEVItector™ II V2 equipment comprises:
1. A high voltage unit (HVU) with a built-in 1,8 kHz
transmitter.
2. A battery-driven Magnetic tracer on crutch.
3. A battery-driven Magnetic tracer - Hand held.
The devices are shown in Fig. 3.
High Voltage Unit
The high voltage unit is used for creating a short
circuit at the fault location by applying a high voltage
between two conductors thus burning the polymer
insulation into a so called carbon bridge at the fault
location.
The HVU also acts as a transmitter exposing the
heating cable to a 1
,
8 kHz square voltage. This signal
generates a magnetic field around the conductors
from the burner terminals along the cable to the fault
location.
Tracer
The tracer is a magnetic sensor which is an open
transformer comprising a ferromagnetic yoke and
a pickup coil. Thus the 1
,
8 kHz magnetic flux from
the heating cable is converted into an amplitude
modulated voltage. This signal is also converted into
an acoustical signal and output to a set of earphones.
A maximum tracer signal indicates the closest
distance to a cable segment. However, this case may
be modified due to the effect of closely neighboring
cable segments. The tracer has a gain and volume
control which allows you to adjust the meter or
volume level to fit the actual depth of the cable.
Fig. 3
: Photo of High Voltage Unit (left), the Magnetic tracer on crutch (mid) and the Magnetic tracer -
Hand held (right).
Note:
The photos are not to scale.
