Hi EMI friends,
I have a system that has equipment enclosed in a steel box, including a PLC that operates some valves. The wires to the valves are twin core 18 AWG, but I have a some 20 AWG that I would like to use.
Does anyone know if using the 20 AWG wire (instead of 18 AWG) would significantly affect EMI such that the system would need recertification ? I'm assuming not, since it's totally enclosed in a steel box, but EMI is crazy stuff, right![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
According to wikipedia, the resistance of 20 AWG is 33.3 milliohm per metre, and 18 AWG is 21 milliohm per meter. The absolute numbers are quite small but the relative difference is quite significant -- an extra 50%.
Increasing the resistance of a wire increases the antenna affect. The valves have a rating of 8VA and operate at 24V. The inrush rating is 30VA. So I'm guessing the current is approx 300mA (or 1.25A inrush). Are these values significant enough to cause significant antenna radiation ? Wire length is approx 1 metre.
Thanks for any info.
Brendan.
I have a system that has equipment enclosed in a steel box, including a PLC that operates some valves. The wires to the valves are twin core 18 AWG, but I have a some 20 AWG that I would like to use.
Does anyone know if using the 20 AWG wire (instead of 18 AWG) would significantly affect EMI such that the system would need recertification ? I'm assuming not, since it's totally enclosed in a steel box, but EMI is crazy stuff, right
According to wikipedia, the resistance of 20 AWG is 33.3 milliohm per metre, and 18 AWG is 21 milliohm per meter. The absolute numbers are quite small but the relative difference is quite significant -- an extra 50%.
Increasing the resistance of a wire increases the antenna affect. The valves have a rating of 8VA and operate at 24V. The inrush rating is 30VA. So I'm guessing the current is approx 300mA (or 1.25A inrush). Are these values significant enough to cause significant antenna radiation ? Wire length is approx 1 metre.
Thanks for any info.
Brendan.