DC Shunt materials


Thread Starter


Need to design a DC Shunt for Current Metering, the max. current to be measured is 1500 A, and I would ideally need a 75 mV drop acroos the shunt at 1500 A.

The voltage I am working at is about 30 V DC.

I need suggestions for shunt materials that can be used for this purpose, keeping in mind size considerations. The shunt needs to be packaged in
dimenstions of about 25cm x 20 cm x 10 cm (LxBxH)

Colin Walker

If you don't need 4 digit precision, I have often used brass shim in the past to good effect. It has good resistive properties, a reasonable
temperature coefficient and a dream to solder or weld. If you need precision then constantinum is a common alloy used unfortunately, not so easy to work with.

Regards Colin WALKER

Michael Griffin

You didn't mention something which is very important - your accuracy requirement. I assume you need better accuracy than you would get from a
hall effect (e.g. LEM) sensor, or you wouldn't be looking at a shunt for something this size.
Have you investigated whether you can get a standard shunt this large? If not (or if a standard model is otherwise unsuitable), perhaps you could get a shunt manufacturer to make a custom one for you. Unless you are designing a product which is intended to be produced in volume, this would probably be your best approach.
I don't know exactly what copper alloy is used in a shunt, but I would like to point out that there is more to the design than just the
material. The thermal and mechanical stability need to be taken into account as well.

Michael Griffin
London, Ont. Canada

Curt Wuollet

That should be available commercially. That's 112.5 watts of dissipation and will need space or cooling. You can make your own from constantan
sheet and copper, I would suggest that you shoot for less drop or possibly consider hall effect sensing to keep the heat down. There are other commercial alloys with the desired zero tempco of resistance.



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Try University of Texas, Balcones Center for ElectroMechanics, in Austin.

They developed a 10 million Ampere shunt with extremely low voltage drop. If I remember correctly it was about 100 mV.

Phil Corso, PE
(Boca Raton, FL)

Vladimir E. Zyubin

Dear List,

Jast a remark:
the main problem for the case of high power conversion measurement is to provide an exceptable quality of the measurements(accuracy, if you like)... to provide uncertainty within 50% of real value is not a big problem... to provide 0,5% seems like impossible... :-(
Unfortunately, Mr. Aditiyas did not provide any info on this.

Best Regards. Vladimir.