Test-disconnect terminals are mainly used for electricity generation and supply applications. They are perfect for the wide variety of switching demands in the current-transformer secondary circuits that predominate in these applications. Current transformers must always have a closed secondary circuit, for use when electricity meters and measuring instruments are being replaced, or when making comparative measurements.
All versions provide touch-safe protection in compliance with BGV A3. A captive, screw-on sliding partition is used to separate the current and voltage paths. The switch position is always easy to detect since the disconnect screw has a yellow insulating sleeve. In all versions, the STBI19/4 socket plugs can be contacted for a test pick-off using the PS 4 test plug or the conventional (4 mm) insulated test plugs.