Buy Current Shunt Resistors
These current shunt resistors feature industry standard Manganin metal resistance elements for temperature stability. They provide four-wire "Kelvin" connections for accurate measurement of the shunt's voltage drop.
Learn more about a current shunts operation...
See product specifications below. Please contact us regarding quantity orders for current shunts with other current and voltage ratings.
B Series Current Shunt
500 Amp max. rated with 100 mV output. (0.0002 Ohms)
model number: CSB500-100
3.25" L x 1.75" W x 1.75" H. Weighs 11 oz. Full mechanical dimensions (popup).
Has 3/8" dia. bolt power terminals. 0.205" ± 0.015" diameter mounting holes on 1.25" ± 0.03" centers. Kelvin screw terminals have 1.0" ± 0.03" typical centers separation.
A Series Current Shunt
100 Amp max. rated with 100 mV output. (0.001 Ohms)
model number: CSA100-100
2.00" L x 1.25" W x 1.68" H. Weighs 3 oz. Full mechanical dimensions (popup).
Has 1/4" dia. bolt power terminals. 0.205" ± 0.015" diameter mounting holes on 0.875" ± 0.03" centers.
Current Shunt Resistor Specifications
All our current shunts are calibrated to ± 0.25% accuracy at room temperature (20 °C, 68 °F).
Temperature drift of the measured voltage is typically 0.002% per °C (1.8°F).
They are manufactured to meet GSA federal CID-A-A-55524 specifications which supersedes military specification: MILS161B.
Note that for continuous operation in room temperature freely circulating air, the shunt should be operated at only 66% (2/3) of the "rated current". E.g. a 500 Amp shunt is good for 333 Amps continuously.
You should keep the shunt's operating temperature below 145°C to prevent permanent change to its resistance. 90 °C (194° F) on the resistive strips is a good operating maximum to stay within specification. Mounting the shunt so that air can flow vertically between the shunt blades will improve cooling. e.g. with the shunt mounted horizontally on a vertical wall.
Shunts have a phenolic base with two holes for mounting screws. Terminal blocks are solid brass.
The large bolts are for the high-current carrying ohmic) connection. These are where you connect your current carrying wires. The small screws are for the shunt voltage (kelvin) measurement connection. These wires carry very small current and are used to measure the voltage drop across the shunt. Very small voltages are involved, so you don't want any unecessary IR drop effecting your readings. This is why the kelvin connections are usually placed closer to the shunt element than the ohmic connections.
Buy Current Shunts