Current Measurements using Shunt
1. Explanation of
”Shunt”
“Shunt” is the resistor used for the measurements of circuit currents in electric
circuits.
Actually, shunt was previously taken as the resistor connecting up to the
ammeters in parallel to expand the measuring range of electric indicating
instruments (indicating meters). *See Diagram1
However, recently shunt is more commonly used as the sensor that detects the
circuit currents.*See Diagram2
There are various ways to detect the currents, but using shunts is the most
simple to just connect up to the measuring circuits in series.
This is the method for measuring and detecting the voltage commensurate with
the currents generated in the shunt connecting up to the circuits.
In order to insert the shunt to the circuit in series, adequate resistance value
setting for circuit operation is needed.
Shunt
Power Supply
Load Side
Ammeter
(Diagram1)
Secondary Output Terminal
Shunt
Power Supply
Load Side
Detecting Circuit / Transducer
Control Circuit
(Diagram2)
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Digital Panel Meter
or other equipment
2. Proper Usage
3 typical case examples in measuring DC10A
1) Indicating meter
Product
Shunt
:
10A/60mV (*Example : YS-1-10A60mV)
Meter
: Sensitivity 60mV Scale 0-10(A) (*Example : Y-80 60mV)
[Connecting Diagram]
Shunt : YS-1
Meter : Y-80
2) Digital Panel Meter
Product
Shunt
: 10A/100mV (*Example : YS-1-10A100mV)
Digital Panel Meter
: Input Sensitivity : 200mV
(*Example : YAP-101 : Maximum Display 1999)
[Connecting Diagram]
Shunt : YS-1
Digital Panel Meter : YAP-101
*Decimal Point Lighting : Triple Digits
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3) Transducer or other equipment
Product
Shunt
:
10A/60mV (*Example : YS-1-10A60mV)
Transducer
: DC Voltage Transducer
(*Example
CSV-「03」
「11」
「E」 / Input : 60mV, Output : 5V)
[Connecting Diagram]
Shunt : YS-1
Transducer
Control Device
<Scale Conversion>
In this case, scale conversion is needed. In short,
10A⇒Shunt secondary output
:
60mV⇒Transducer output 5V
That means Current 1A goes 0.5V at transducer output.
Double value of transducer output Voltage means Current Value at 10(A)/5(V).
Adjustment like this (Scale Conversion) is needed at control device side.
3. Other
Caution in setting up the current measurement circuit using shunt
1) Shunt is connected to the measuring circuit directly, please take care the
risk of electrical shock in insulation.
2) In case of scale conversion between shunt secondary Voltage and
measuring Voltage is needed, please specify the value of shunt output and
measuring instruments input In ordering.
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