Riedon, a company specializing in advanced resistive systems, has launched a new range of precision current shunts that are specifically developed for DC ammeters and other similar devices. The RS Series of base-mounted shunts is RoHS-compliant and UL listed and provides current ratings ranging from 5A to 1200A.
These off-the-shelf shunts are also cost-effective and provide short lead-times. They are suitable for the renewable energy sector such as wind turbines, solar arrays as well as battery chargers for storing energy in electric vehicles.
When using a shunt resistor for current measurement, it is important to determine the small voltage drop across a precision shunt resistor. Riedon supplies standard parts that provide outputs of 50 and 100mV, but custom output voltages are also available. Manganin resistive elements provide low resistance values of 0.05mΩ at 1000A and 10mΩ at 5A needed for shunt resistors. These values are accurately etched to a typical tolerance of ±0.25%. Riedon also supplies ±0.1% devices.
The RS Series is separated into three different types of body styles depending on the current rating. All precision current shunts include a 4-terminal design that divides the voltage sensing terminals from the load carrying connections. The terminals in the RSC (800, 1000 and 1500A) units are made of copper, while those in RSA (5-150A) and RSB (170 - 600A) units are made of brass. Operation is stipulated between-40oC and +80oC temperature with a dielectric strength of 750VDC and a temperature coefficient of resistance of ±15ppm/oC.