Adapter for a safe operation of Teleflex reflectometers on overhead line systems

Very easy to operate

Very good resolution, for both near and distant ranges

Dangerous induction voltages reliably discharged

Connection to a measurement system

Test pulses up to 1,500 V for long distances

For distances over 2,000 km

Used together with a reflectometer, the measuring

equipment can show impedance irregularities in disconnected

overhead lines of all voltage levels. These

include short circuits, breaks and intermediate conditions.

It is mainly used for checking the overhead line

before it is switched back on, to avoid damage from

travelling waves and problems endangering life. Regular

checks can also be performed, in particular to

detect any changes. The special design and switch-on

system prevent risks to the operator and damage to

the equipment from induced voltages and currents.

The overhead line is tested by means of a switch-on

unit and a Teleflex reflectometer which are attached

to the disconnected line with a resistance wire. During

the measurement, the switch-on unit safely conducts

dangerous, induced energies to earth.

The following conditions can be detected with the test:

»» Breaks, short circuits and branching off

»» Smaller changes in impedance such as poor

connections, faulty insulators and in-growing trees

»» Changes in cross section and sags in the line

However, the smaller impedance changes can often only

be seen in a comparative measurement against a fault-free

line or a saved reference curve.

Scope of delivery

»» Teleflex

»» Clamp ammeter

»» 40 A switch-on device / pulse generator

»» 5 or 10 m earthing system, consisting of:

- Earthing cable

- Earthing lead

- Auxiliary earthing lead

»» Mains extension lead (50 m cable reel)

»» Telescopic test pole with cable guide and

conductor screw terminal

»» Protective resistance (fuse wire)

»» Switch-on lead with coupling

»» Earthing terminal for ball pin

2 versions are available:

A standard system coupled to an active reflectometer,

with the test pulses fed into the measurement

object.

An overhead line system with pulse generator where,

in passive mode, the reflectometer acts as a transient

recorder. This system also has its own test pulse

generator, specially adapted to the requirements for

measuring very long overhead lines, 1,000 km and

longer.

Highly powerful pulses of 1,500 V and a pulse width

of 20 μS allow very large distances to be easily tested.

The Teleflex is used as the basic device for all the systems

– either as an individual device or when installed

in the measurement system. It can also be fitted

permanently in a station.

The tests can be undertaken with one, two or three

phases (sufficient switch-on units are required for

this).