18 | MONITOR | 2/2019 INNOVAT I VE PRODUCTS SensorPRO Residual Current Moni toring Device CTBS25 und RCMB330 However, since nowadays almost every installa- tion includes non-linear loads and therefore the residual current can potentially contain DC com- ponents, 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. Market-driven solutions for modern applications Split-core type B measuring current transformers These systems usually result in a need to install so-called measuring current transformers in the installation; to do this, the feeder cable often needs to be disconnected so that it can be routed through the current transformer. The instal- lation 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 trans- formers, 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. 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 so that downtimes can be reduced, for example by assisting with preventive maintenance. Options include installing residual current monitoring systems (RCMS), which also contribute to a reduction of the disconnection times required for insulation tests in line with DGUV (German Social Accident Insurance) Regulation 3. Sensor PRO CTBS25 and RCMB330