Dulas Solar VC150, Handbook

Page: 49 / 156

49
2.3.2 Using a current shunt with a millimeter or milivolt meter to measure
current.
1.
Switch OFF the system. Disconnect the wire at the terminal where you want
to measure the current.
2. Select a current range that included the current yu expect to measure.
Connect the shunt between the disconnected wire and the terminal and
connect the probes of the millimeter to each terminal of the current shunt.
3. Select the mili-volt range on the millimeter which includes the mili-volt range
identified on the current shunt, and proceed to measure the mili-volt across
the current shunt as shown below.
4. The value read on the meter in mili-volts is converted to current (amperes) by
multiplying this number by the number of amperes, which are equivalent to 1
mili-volt as indicated on current shunt.
Example:
Current shunt is marked 20 A. 200 mV
Hence 200 Mv is measured if 20 Amps is flowing the wire so, 1 mV is
measured if 20 Amps is flowing in the wire (We divide by 200 to find
the equivalent of 1 mV).
So, 1MV= 0.1 Amp
If, for example the reading on millimeter is 55 mV
Across the shunt connections we have 55 mV (mili-volts)
Therefore in the circuit we have 55 * 0.1 Amps= 5.5 Amp
Current in circuit= 5.5 Amps