Measuring devices connect to a Dc Shunt

[mash98]

Dear guys how many devices can be connected to a dc shunt for protection and monitoring without too much compromising on accuracy, assuming the input impedences are very high? The dc shunt specs are 100mv at 3000 amperes.

regards

 

[Skogsgurra]

The first problem is what common-mode voltage the shunt is at. If it is part of a DC drive system or a power rectifier at elevated voltage, you have to be very careful.

The second problem is to avoid errors due to high-frequency components in the common-mode voltage.

Then, there is an issue with short circuit currents. You probably need to fuse your measurement wires.

Your least problem is the load that measurement and protection devices constitute. The internal resistance of the shunt is 33 micro-ohms, so you can connect hundreds of 1 megohm loads before even getting close to a loading problem.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[mash98]

thanks, it is for measuring the dc motor current,yes the voltage level is relatively high i,e 700 volts and we will take the neccessary precautions.

regards