Can I use the KA2803 (Earth Leakage Detector) in a HV DC line?

[flote21]

Hi guys!

I need to design a voltage leakage earth detector for Photovoltaic installations with a DC bus in the range of 800V - 1.5KV. The leakage must be detected when there is shortcircuit between whichever of the DC lines and Earth. But sometimes the shortcircuit is not clean. Sometimes the shortcircuit between Earth and one of the DC lines has an impedance in the range of 0Ohm - 80KOhm. Therfore, my design needs to detect the impedance of the shortcircuit giving a shortcircuit error. Example:

- My design is tirggered with a 10K of Resistor Leakage. The ouput relay of my design gives a "High Level" when the shortcircuit between whichever of DC Lines is shortcircuitted to Earth with an Impedance <=10KOhm. Otherwise the output relay will "Low Level".

I have been thinking to use the KA2803 to accomplish this task, but the datasheet recommends this device for AC lines. Do you think can I use it for DC lines? In which way?

Any other idea to accomplish this task? Whichever approach will be very welcome...

Note: Find attached a datasheet of a commercial solution equivalent to the design I want to do.

Thanks in advance and greetings.

 

[FvM]

KA2803 is intended to build RCD relays with current transformer, the shown insulation monitor uses a completely different measurement method.that is able to detect ground faults in IT (unearthed) systems.

Read application brochure from major manufacturer Bender how insulation monitoring works Isolationswiderstand_PMUe_8er_engl.indd (bender.de)