alwaink
Electrical
- Oct 26, 2004
- 41
Hi,
For cable insulation resistance calculation, the equation goes:
IR = K * log (D/d) [megaOhm-1000ft]
where D = diameter of insulated conductor
and d = diameter of copper inductor
ICEA has some K numbers for PVC and rubber. But how is K calculated? It's nowhere explained. I've come across this equation for K, but the source is not cited:
K = (p*2.3026E-6)/(2*pi*12,000*2.54) where p = volume resistivity [ohm-cm]
The denominator (2*pi*12000*2.54) is simply conversion to 1000ft. But I'm not sure what 2.3026E-6 is. Has anybody seen this equation from any standard so that I can cite the source in my document please? Or would this be like a common-sense V=IR equation that I'm not aware of?
Thanks
For cable insulation resistance calculation, the equation goes:
IR = K * log (D/d) [megaOhm-1000ft]
where D = diameter of insulated conductor
and d = diameter of copper inductor
ICEA has some K numbers for PVC and rubber. But how is K calculated? It's nowhere explained. I've come across this equation for K, but the source is not cited:
K = (p*2.3026E-6)/(2*pi*12,000*2.54) where p = volume resistivity [ohm-cm]
The denominator (2*pi*12000*2.54) is simply conversion to 1000ft. But I'm not sure what 2.3026E-6 is. Has anybody seen this equation from any standard so that I can cite the source in my document please? Or would this be like a common-sense V=IR equation that I'm not aware of?
Thanks