A range of UL listed, RoHS-compliant, precision current shunts have been launched by Riedon. Designed for DC ammeters and similar instruments, the base-mounted RS Series offers current ratings from 5A to 1200A and are targeted at applications in the renewables energy market, such as solar arrays, wind turbines, and battery chargers. The company claims that the shunts deliver the industry’s shortest lead-times.
Current measurement using a shunt resistor depends on measuring the small voltage dropped across a precision resistor placed in series with the load. Offering standard parts that provide 50mV and 100mV outputs, Riedon are also able to provide custom output voltages. The very low resistance values required for shunt resistors, 10mΩ at 5A and just 0.05mΩ 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.
The RS range has three different-sized body styles determined by current rating. Separating the heavy-duty load carrying connections from the voltage sensing terminals, all devices in the range feature a 4-terminal design. 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 -40oC to +80oC with a temperature coefficient of resistance (TCR) of ±15 ppm/oC and a dielectric strength (terminal block to base) of 750VDC.
“Our in-house manufacturing and design capability it what sets Riedon apart from many other suppliers. We can compete on price and delivery while also supporting custom designs,” said Phil Ebbert, Riedon’s VP of Engineering, “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”