Burden Resistor calculation: Difference between revisions
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'''R''': Burden resistor value in Ohm<br> | '''R''': Burden resistor value in Ohm<br> | ||
'''Vadc''': ADC | '''Vadc''': ADC reference voltage <br> | ||
This is 3.3V for all RPICT3T1 RPICT3V1 and RPICT8/RPICT7V1/RPICT4V3 in version 3 and earlier.<br> | |||
This is 4.096V for all RPICT8/RPICT7V1/RPICT4V3 in version 4 and 5.<br> | |||
'''Nturns''': Number of CT sensor turns (see specs). <br> | '''Nturns''': Number of CT sensor turns (see specs). <br> | ||
:SCT-013-000 is 2000 turns.<br> | :SCT-013-000 is 2000 turns.<br> | ||
Revision as of 11:11, 10 February 2022
Burden Resistor Formulae
R: Burden resistor value in Ohm
Vadc: ADC reference voltage
This is 3.3V for all RPICT3T1 RPICT3V1 and RPICT8/RPICT7V1/RPICT4V3 in version 3 and earlier.
This is 4.096V for all RPICT8/RPICT7V1/RPICT4V3 in version 4 and 5.
Nturns: Number of CT sensor turns (see specs).
- SCT-013-000 is 2000 turns.
- SCT-019 is 6000 turns.
- SCT-006 is 800 turns.
Nturns can be deduced dividing primary current by secondary current. For example the SCT-013-000 is rated as 100A/50mA. Therefore we get 100/0.05 = 2000 turns.
Irms: Max current to be read in Ampere (rms)
Current Coefficient Formulae
This will compute ICAL.
ICAL = Nturns / R
ICAL: Current Coefficient
Nturns: Number of CT sensor turns
R: Burden resistor value in Ohm