Burden Resistance for CT ZMCT118F for ampere value

Other Hardware Sensors
1

Hi am using CT "ZMCT118F" . i need to know its burden resistance.
I calcultaed my self

for Arduino uno 3.3V = burden resistance is 39.2ohm
5V = burden resistance is 59ohm
dividor resistance is used is 100k ohm.

ZMCT118F specification shows it takes maximum of 30A. so what will be the output analog value of CT
at
1 ampere
5 ampere

Please advice .
Thanks.

2

You haven't posted a link to the datasheet for that CT

3

A simple google search gave me this: The burden is 1 mA per amp so the formulas are here: https://5lrorwxhmqqiiik.leadongcdn.com/ZMCT118F+specification-aidilBqoKomRilSnpomjnkp.pdf . Since it is a CT the burden as I believe you are calculating is correct. One bit of information that may mess you up is the output is not DC it is AC. So to use with the arduino you need to rectify it and use a low pass filter to convert to DC. This is just a little extra information as you did not say if it was a AC or DC application. This response is to help you get started in solving your problem, not solve it for you.
Good Luck & Have Fun!
Gil

4

AFaisal:
Hi am using CT "ZMCT118F" . i need to know its burden resistance.
I calcultaed my self

for Arduino uno 3.3V = burden resistance is 39.2ohm
5V = burden resistance is 59ohm
dividor resistance is used is 100k ohm.

Those resistance values are correct for 30Amp.
I assume with 100k you mean the 2*100k voltage divider to bias the pin mid-voltage.

AFaisal:
so what will be the output analog value of CT
at
1 ampere
5 ampere

Current x turns ratio x burden resistance.

1Amp > 10.00159= 59mVAC, is 0.05921.414= 160mV peak peak.
5Amp = ~1volt peak peak.
30 Amp = ~5volt peak peak
Leo..

5

Hi i am working with OPEN ENERGY MONITOR

Current sensing electronics

1x CT sensor SCT-013-000
1x Burden resistor 18 Ohms if supply voltage is 3.3V or 33 Ohms if supply voltage is 5V
2x 470kOhm (for voltage divider, any matching value resistor pair down to 10K)
1x 10uF capacitor

mY QUESTION IS WITH ANALOGREAD VALUES

  1. If i use 3.3v supply voltage, then what is analog read resolution(0 -> ???????? == 0 -> 3.3v)plz suggest

  2. If i use 5v supply voltage, then what is analog read resolution(0 -> 1023 == 0 -> 5v)

Second if there is little difference in BURDEN RESISTOR value then what will be the effect at analog output values? Like
a) if 20ohms or 22 ohms are used instead of 18ohm
b) if 30 ohm or 36 ohm are used instead of 33ohm.

Thanks.

6

It sounds like it's talking about using 3.3 or 5v Arduinos. If you use the default Arduino ADC setting that uses the supply voltage as the reference then the resolution is 3.3/1024 or 5/1024.

If you were to use the internal voltage reference (and adjust the bias voltage) then it'll be 1.1/1024 for both, but then you only have a 1.1v working window.

The higher the burden resistor the higher the voltage output per amp. Deviating from the recommended values may give false readings (check the datasheet). Operating without a burden resistor may result in Arduino destroying voltages.

7

And you can’t read an A/C signal that has negative going voltages

8

Why did you start a new thread for the same project.
Leo..

9

Threads merged.