The PIC32CXMTSH-DB is compatible with various types of current sensors. It is possible to
use an arbitrary combination of the following current sensors, subject to input voltage
specifications:
Current Transformers (CT)
Shunt Resistors
Rogowski Coils
Warning: A shunt
resistor must be placed in series with the line to be measured, then connected to
the measurement inputs. The demonstration board is referred to neutral; therefore, a
shunt resistor can only be used in neutral line. Using a shunt resistor to measure
currents in lines 1 or 2 will damage the board, and it is dangerous for the
user.
Attention: Note that this kit does not include any CT, Rogowski coils or Shunt current
sensors.
Each current sensor (CT, Shunt or Rogowski Coil) must be connected to two positions of
the same connector. The current input lines are distributed to an A/D converter through
a configurable filter whose function is to adapt the chosen current sensor. Both inputs
have the same filter configuration and layout. Their ground reference is GND.
Important: By default, the
PIC32CXMTSH-DB board is configured to host a current transformer. The board is
populated with resistors R63, R65, R67 and R69 of 1.62Ω to fit a standard 200A CT
with 1:2000 turn ratio. Using default installed burden resistors of 3.24Ω (2 ×
1.62Ω), a 2000:1 CT ratio will allow a max of 240A. (240 Arms × √2 × 3.24Ω/2000 =
0.55 Vpk).
Figure 3-13. IPx and INx Current Sense
Schematic
Some test points close to the A/D converter inputs allow monitoring the input voltage
value at the A/D converter inputs corresponding to the current:
TP29: IP1 input measurement
referring to GND
TP33: IN1 input measurement
referring to GND
TP30: IP2 input measurement
referring to GND
TP34: IN2 input measurement
referring to GND
Figure 3-14. IPx and INx Test
Points
The online versions of the documents are provided as a courtesy. Verify all content and data in the device’s PDF documentation found on the device product page.
