The requirements placed on industrial systems and installations in terms of high availability are constantly increasing. This means that it is also becoming increasingly important to equip existing applications with monitoring technology, for example by assisting with preventive maintenance.
When measuring current transformers are installed in the installation, the feeder cable often needs to be disconnected so that it can be routed through the current transformer. The installation always needs to be switched off for this to be done – which is not really an option for high-availability existing installations.
One solution for this are split-core measuring current transformers, which have been available from Bender for many years – at least in the field of AC and pulsed DC sensitive measuring current transformers. These components can be installed retrospectively with ease in existing installations. However, since nowadays almost every installation includes non-linear loads and therefore the residual current can potentially contain DC components, there is a growing demand for AC/DC sensitive residual current monitoring systems. Based on this development and the increasing importance of high availability, more and more split-core AC/DC sensitive current transformers are required, which can be installed without disconnecting the installation and can be used for reliable monitoring of the system – even with existing DC fault currents.
The split-core residual current sensors type B series expands Bender’s portfolio in the field of residual current monitoring and measuring current transformers with new sensors for measured value acquisition and evaluation. They are foldable and can therefore be retrospectively installed without any problems on permanently installed cables.
The new devices come in two different versions: as a CTBS25 sensor variant for connection to an external evaluator (e.g. RCMS460 or EDS440), and as an intelligent RCMB330 device with an integrated evaluator. The RCMB330 includes evaluation of the RMS value of the residual current, which is provided as a standard feature on Bender RCM devices. However, at the same time it is also possible to evaluate the AC and DC components separately. In addition, the intelligent, split-core current transformer includes the bulk of the new features of the SensorPRO series.
With the split-core devices, Bender will now be offering smart, single-channel solutions for retrofitting applications that come with the huge advantage of allowing simple installation in existing systems: fold open the current transformer, route around the conductors, close again and wire the interface – done! The installation does not need to be switched off for this.
At the market launch the new split-core measuring current transformers will initially be offered with an internal diameter of 25 mm. However, other sizes are expected to follow soon if the series is well received.
With the features of the SensorPRO series, the open communication and the split-core design, the sensors offer a high degree of flexibility and are thus future-proof for use in the vast and diverse range of modern applications.