power cables by themselves do not cause fires, they are oftentimes the victim of abuse and wrong application by unwitting users.....
these power cables get burned out if the socket outlet is loose, if there was a short at the load side, this is the reason why in Singapore all power cables are fitted with 13amp fuse right at the plug side(kaya malalaki ang plugs nila) so that in the event of a short circuit, the power cable will not burn out.....the fuse just opens up...
again, not always. example i cited is proof.
i've used for almost 8 years the same powerstrip and various cables. only that particular oem cable pop (heard it with my ears) and burnt. again, 2 other friends experienced the same on exactly similar oem cables of exactly similar tube headphone amps.
i am merely pointing out all possible sides to this....
in this hobby, some details are oftentimes left out....maybe because the proponents themselves are not in the know........i would like to give readers a chance to see the bigger picture and then decide....an informed decision is the best imho....
no. you focused on electrical arc and it seem like you refuted/negated cable overload which is also a possible cause specially with 3 actual occurrence i mentioned previously. am i right ?
no rule of thumb and no justification, just the thickness of your wallet and how happy you can feel after your purchase, after all isn't that what life is all about? enjoyment....
possible. perhaps, it is better and more fun to skimped on wires and enjoy the thinnest possible wires/cables. after all, SAFETY is NOT important. burned houses and possible lost of human lives are of less value. indeed, not in the know
numerous articles/readings about this overload issue. here are some examples =>
1) Overloading may have caused short-circuit
http://articles.timesofindia.indiatimes.com/2012-05-24/vadodara/31839883_1_fire-brigade-overloading-power-cables2) Effect of Over Current on Cables
http://sourcing.indiamart.com/electrical/articles/effect-over-current-cables/Over Current
In any wiring system, over-current is one of the two main safety hazards that should be in control. It is very risky and dangerous because it lead to a risk of fire. Most of the fire accidents are caused due to electrical faults. A fuse or MCB of the same current rating as the cable should be selected to work properly.
Over current is an increment in the amount of current above certain level. Cables become heated when current flows through them and it is a normal process. The level of heat is permissible only up to a specific point and any thing above it would be dangerous.
3) Overcurrent Coordination Basics Cables
http://www.skm.com/applicationguides8.html• If current penetrates the limits of the thermal overload curve, cable insulation life is reduced.
• If the maximum thru-fault current penetrates the limits of the short circuit damage curve, insulation damage will occur. The thru-fault current is defined as the maximum current that can flow for a fault at the load-side terminals of the feeder.
btw, i am NOT a seller of any cables/wires.. nor burnt houses