Tool/software:
Hi Team,
I have a question for Insulation resistance when Rp is connected to 0R and Rn is not connected.
Should Rn be a very large value?
The picture below is the value obtained according to your company's formula. Sometimes Rn is 0, sometimes it is negative.
Is there any way to get the correct value?
Thank you so much.
Hello Lee,
Thanks for reaching out to our team on E2E. I'm not sure why that calculator tool is behaving like that, might be some error with the formula or rounding error.
Please try using these attached calculators instead, one takes ADC voltages as inputs to calculate the insulation resistance, and the other takes insulation resistances to calculate the ideal ADC voltages.
Best regards,
Tilden Chen
Solid State Relays | Applications Engineer
Hi Tilden Sir,
Setting as below,please help to check,Thank you so much.
Rp: 0R
RN: 99000000
If the formula calculates Rp and Rn is zero, can the correct formula be provided to calculate Rn as 99000000?
Or is there any limitation that doesn't make it possible to calculate Rp or Rn?
Hello Lee,
There are limitations to what the equations can solve for. I think you can calibrate the range of acceptable ADC voltages to determine when there is a problem. We can use this system as an example, what is your fault condition?
100 ohm/V would be 30 kohm, so fault if either RisoP and RisoN is less than 30 kohm. So normally you might see 0.04 V and 0.74 V.
As VADC start to become equivalent, there is a problem. There will be a finite limit to how accurate this detection is depending on the ADC accuracy. In this example, as both voltages become close to 1.47 V, there is a fault.
Best regards,
Tilden Chen
Solid State Relays | Applications Engineer
