Safe rail transport
A key aspect for the smooth operation of rail transport is to ensure continuous
operability. One of the parameters is ensuring the electrical safety of the power
supply parts, signalling and safety systems, tunnel installations, as well
as towing vehicles. A common aspect of these complex power
systems is that in the long run, the installation is almost certain
to avoid insulation problems.
If we consider that the power supply system in railway transport must meet high
demands on operability and safety, it is logical that the installation is carried out
using an isolated system, which is then
monitored by means of isolation condition watchdogs.
However, the power supply system does
not have to be monitored only by isolation watchdogs as required by EN 615578, but can be actively searched for isolation faults during operation according
to EN 61557-9 and thus use systems for
locating isolation faults, whether permanently installed or portable.
Specific environments and applications
also require higher demands on equipment resistance to shock, vibration and
requirements for a wider range of operating temperatures.
For DC networks, it is also a useful parameter to determine which pole the insulation fault occurred in and also the measured value of the L+/PE and L-/PE voltages
with respect to grounding.
The response to these requirements features isoHV and isoRW series that have
been specifically developed and tested by
many years of practice.
T + T Technika a trh 5/2023
As the product name suggests,
ISOMETR is a device that is designed to
monitor the insulation condition with specific characteristics for Rail-Ways. All devices are designed not only for rail transport
They already monitor more
than 5600 IT systems
applications, but also wherever demanding conditions for operation and reliability are required.
It is only thanks to you, our customers,
who trust these devices and their reliability that we can say that these devices monitor more than 5,600 power systems in
rail transport today.
The result of several years of development by engineers is the very compact
monitoring device isoHV425W, which allows monitoring of insulation resistance in
networks (IT) with a voltage of 0–1 000 V
3(N)AC, AC/DC. The DC components in
combined AC/DC systems do not affect
the operating characteristics of the equipment. It enables applications in the most
adverse conditions with an operating temperature range of –40 to +70 °C. These
devices are ideal for applications that
may be subjected to severe shocks or vibration. A separate, isolated power supply allows monitoring of systems without
The devices meet the requirements of
standards ČSN EN 61557-8 and ČSN EN
• Measurement of the insulation condition of IT networks 3(N)AC, AC/DC
• Measurement of mains voltage to grounding L+/PE and L–/PE
• Setting parameters via the web interface
• L+/L– isolation fault detection with independent signalling on programmable output contacts
• Measurement and self-adjustment of the dispersion capacity of the network
• RS-485 bus with Modbus RTU or TCP protocol and analogue output
(depending on the type of device)
• Option to protect the device settings with a password
• Operating temperature from –40 °C to +70 °C