User Manual

Connecting signals
Press
Press to return to the measurement display.
The PA3000 is now ready to make measurements using a CT.
To connect an external resistive shunt
Using a resistive shunt is a straightforward method of extending the current
measuring range of the PA3000. The shunt resistor is connected in series with the
load and the voltage across the shunt is directly proportional to current.
That voltage can be connected directly to the External Current Inputs of the
PA3000.
For example, a 1 mΩ shunt is used to measure 200 A
rms
.
1. Check that the voltage that will be generated is suitable for the PA3000
V=IxR(Ohm’slaw)
Vshunt
=IxRshunt
Vshunt = 200 A x 0.001 Ω
Vshunt = 0.2 V
This is well within the 20 V
pk
rating of the PA3000’s External Current Inputs
2. Connect the shunt in series with the load and to the EXT AHI and EXT A LO
inputs as shown.
Figure 19: External resistive shunt connections
PA3000 Power Analyzer User Manual 31