So I'm buying cable that is rated to 600VAC. The thing is, I'm running DC current through it. Should I be worrying about this or does a 600 VAC rating extend to 600 VDC?
Should be ok. Im an electrician but i am not 100% sure if it will be ok but it should be dont deal with much DC. What are you getting 600v DC from and what current is it carrying?
dont know but voltage dosnt really matter its the current that matters. I mean if you look in your house different things are wired in different sizes of cables like 1.5mm for lights 2.5mm or 4mm for sockets and stuff cookers and showers n that will be between 6mm and 15mm. All things run on a 240v supply (in UK anyway) so its just the current (A) that increases teh size of cable needed.
But since V=IR to increse the current, I = V/R, the resistance must be as small as possible. Hence, as a small cable provides greater resistance to increase the current you must just simply increase the size of the cable, providing less resistance and hence providing a higher current?
I'm pretty sure that AC would require LESS voltage rating, because of its sine-wave nature. It passes from the max voltage (peak) to the NEGATIVE peak and back to the positive peak X cycles per second (e.g. 60hz passes from + to - peaks 60 times a second). Whereas DC is a sustained voltage at the peak value at all times. This is why AC is measured in different ways-- peak (Positive peak to 0V), peak-to-peak (full difference of voltage between + and - peaks) and VRMS (root mean square).
Thanks for all of your input everyone. To answer on what i'm doing with this, I need to power a small remotely operated underwater vehicle via a tether and need to spec cable that will withstand the environment (seawater, 100 metres depth, etc.) and these specs I believe for 600 VAC. Cheers