Voltech PM1000+, Руководство пользователя

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U
SING
V
OLTAGE AND
C
URRENT
T
RANSDUCERS
Page 22 © Voltech 2010 Power Analyzer User Manual
Use the delete key to clear the entry.
Type the new scale factor (100)
Press OK
Press „MENU‟ to return to the measurement display.
The is now ready to make measurements using a CT.
3.3.
T
O CONNECT AN EXTERNAL RESISTIVE SHUNT
:
Using resistive shunt is a straightforward method of extending the current measuring
range of the . The shunt resistor is connected in series with the load and the
voltage across the shunt is directly proportional to current.
That voltage may be connected directly to the External Current Inputs of the .
For example, a 1milli-ohm shunt is to be used to measure 200A rms.
1. Check the voltage that will be generated is suitable for the
V = I x R (Ohm‟s law)
V
shunt
= I x R
shunt
V
shunt
= 200 x 0.001 Ohms
V
shunt
= 0.2V
This is well within the 1V rating of the
‟s External Current Inputs
2. Connect the shunt in series with the load and to the EXT-HI and EXT-LO inputs
as shown.