Specialist low cost DC current shunts offer accurate measurements to 1200A

September 03, 2014 // By Graham Prophet
A range of UL listed, RoHS-compliant, precision current shunts is designed for DC ammeters and similar instruments. Riedon’s RS Series of off-the-shelf, base-mounted shunts offers current ratings from 5A to 1200A and combine low cost with shortest lead-times plus a custom design capability caters for more unique requirements.

Riedon's RS range is divided into three different-sized body styles determined by current rating. All feature a 4-terminal design, which separates the heavy-duty load carrying connections from the voltage sensing terminals. Terminals are brass for the RSA (5 - 150A) and RSB (170 - 600A) parts but copper for the RSC (800, 1000 and 1500A) units. Operation is specified over a temperature range of -40C to +80C with a temperature coefficient of resistance (TCR) of ±15 ppm/C and a dielectric strength (terminal block to base) of 750 VDC.

These devices are targeted at applications in the renewables energy market, such as solar arrays, wind turbines, and battery chargers for energy storage in, for example, electric vehicles, as well as other uses in heavy industry, electroplating and mining.

Riedon offers standard parts that provide 50 mV and 100 mV outputs but can also provide custom output voltages. The very low resistance values required for shunt resistors, 10 mΩ at 5A and just 0.05 mΩ at 1000A, are provided by Manganin resistive elements. These are precision etched to a standard tolerance of ±0.25%, with ±0.1% devices also available.

“We can compete on price and delivery while also supporting custom designs,” said Phil Ebbert, Riedon’s VP of Engineering claiming, “And, as far as I know, Riedon is the only manufacturer to offer precision DC ammeter shunts that are UL approved and fully RoHS compliance”

Riedon, www.riedon.com