Voltage detection on railway catenary systems

The BO-A 2.0 is a voltage detector for railway catenary systems, which is used to determine the presence or absence of voltage in accordance with the five safety rules:

• Disconnect completely
• Secure against re-connection
• Verify that the installation is dead
• Carry out earthing and short-circuiting
• Provide protection against all adjacent live parts

The BO-A 2.0 is used wherever electrical work must be carried out on the overhead line and the overhead line supply network in a de-energised state. It is also used during normal operation of the systems when the voltage status of the overhead line needs to be clearly determined on railway lines, in railway stations or in tunnels.

Typical applications include measurements on contact wires, suspension cables, mast switches for cross and longitudinal disconnections as well as on feeder, bypass amplifier and feeder cables. Users include railway network operators, overhead line and track construction companies as well as companies responsible for track safety, disconnection and earthing of the overhead line at construction sites.

The devices are available for voltage levels of 15 kV, 11 kV and 25 kV and for frequencies of 16.7 Hz, 50 Hz and 60 Hz. There is also the BO-A DC version for DC voltages in the range from 100 V to 3 kV DC (e.g. for DC overhead lines on trams). The voltage detectors are available either as a three-part plug-in system or with a telescopic stick. The total length is 4.7 m for the plug-in system and 5.4 m for the telescopic stick.

In addition to the plug-in system, there is also a version with a universal adapter, which allows customers to continue using their existing earthing and operating sticks.

Like its predecessor, the BO-A, as well as the BO-A DC, which serves as a counterpart for DC overhead lines, the BO-A 2.0 has been approved by  Deutsche Bahn under the grant ‘3 Ebgw 02.71’ on 28 July 2021. This makes Deutsche Bahn a reference customer for other railway network operators worldwide. In contrast to the BO-A 2.0 devices sold worldwide in accordance with IEC 61243-1, the German market also requires compliance with VDE 0681-6, which is also guaranteed.

The voltage detector BO-A 2.0 is provided with a testing element which checks the indication, the batteries, the evaluation circuit and the measuring tip up to the contact electrode directly after it has been switched on. To further increase safety, the voltage detector can also be cross-checked on a live conductor if one is available.

A bright LED display, which is easy to read even at a distance from the telescopic stick, and a clearly audible acoustic signal reliably inform the operator about the voltage status of the overhead line. Even when used on a system with deviating frequency, the BO-A 2.0 recognises this and clearly alerts the user via the acoustic signal.

The BO-A 2.0 is designed in such a way that it reliably recognises the voltage status even in borderline situations, when the overhead line is disconnected but not earthed and despite adjacent live lines.

If the BO-A 2.0 is connected to the overhead line without being switched on manually before using the switch-on button, it activates automatically as soon as it detects the presence of voltage. The BO-A 2.0 immediately gives a visual and audible warning of the presence of voltage. Depending on the version, this standby function is activated or deactivated at the factory.

Next to the standard version, devices are available with an extended standby time: they do not switch off automatically after 65 seconds as usual, but only after 180 seconds with no voltage applied. This is particularly helpful if additional time is required for earthing and short-circuiting after the absence of voltage test.

According to national regulations (in Germany according to “DGUV Regulation 3”, at least every six years) voltage detectors are subject to maintenance tests. During this test, the response thresholds of the device are checked, and the long-life lithium cell is replaced so that the battery does not need to be changed within the next six years during normal use.

Irrespective of the periodic inspection, a visual inspection must be carried out before each use. The product label should also be checked whether the version of BO-A 2.0 is suitable for the voltage and frequency at the place of use.

In addition to the voltage detectors, Horstmann offers a versatile storage bag that can be used both as a carrier bag and as a rucksack. A major advantage of this bag is that you have your hands free when carrying it in the track bed. Its high visibility colour and reflective stripes ensure that the mandatory high vis vest is not concealed. If required, the bag can be extended with an additional carrier bag, for example, to conveniently transport an earthing stick and the earthing and short-circuiting devices.

The product features and benefits for the user can be summarised as follows:

• Low weight and optional bag – Easy handling and transport
• Complete self-testing – Maximum user safety
• Plug-in or telescopic system – Easy and quick to use
• Bright LEDs and loud acoustic signals – Good perception under all conditions
• Shockproof and long-life battery – Maintenance-free (> 6 years)
• Automatic frequency detection – Increased user safety

You can find further information here