The CBS-2000AB is the hybrid unit of the CBS range, and that is the whole reason it exists: it monitors twenty channels in one enclosure, of which sixteen are type A, taken from toroidal transformers of the Circutor WGC range, and four are type B, taken from transformers of the WGB range. Real installations are mixed. Most outgoing ways carry ordinary loads that a type A channel measures correctly and far more cheaply, while a handful — the drives, the rectifiers, the chargers — can present smooth DC leakage that only a type B channel can see at all. This unit covers both without either buying type B monitoring for every way in the board or leaving the drives unmonitored. Sensitivity is 30 to 3000 mA. All twenty channels are shown on the display; two relays provide alarm and pre-alarm, and integrated RS-485 Modbus/RTU allows continuous logging. Suitable for TT, TN and IT systems, 230 V AC supply. The type A channels respond to sinusoidal AC and pulsating DC residual currents. The four type B channels respond in addition to smooth DC residual current, which is the case that matters: smooth DC leakage magnetically saturates the core of a type A or type AC device and blinds it to any further fault. That is why the drives, rectifiers, EV chargers and photovoltaic inverters belong on the type B channels and everything else does not need to. Manufactured by Circutor (Spain) and supplied under the Function brand; the Circutor catalogue reference is CBS-2000AB. This item is listed in the Norwegian trade under the supplier shorthand "CBS-20AB", which is not a Circutor model code — the manufacturer designation is CBS-2000AB. Supplied by cBallast on quote-to-invoice terms; lead time and freight are quoted per RFQ against the destination Incoterm.