Burden Resistor calculation: Difference between revisions
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R = (Vadc * Nturns) / (2√2 * Irms) | R = (Vadc * Nturns) / (2√2 * Irms) | ||
[[File:Resistor_calculation.png]] | |||
'''R''': Burden resistor value in Ohm<br> | '''R''': Burden resistor value in Ohm<br> | ||
Revision as of 11:06, 10 February 2022
Burden Resistor Formulae
R = (Vadc * Nturns) / (2√2 * Irms)
R: Burden resistor value in Ohm
Vadc: ADC max voltage range (usually 3.3V)
Nturns: Number of CT sensor turns (see specs).
- SCT-013-000 is 2000 turns.
- SCT-019 is 6000.
- SCT-006 is 800.
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