3 ms·

Voltage is only half the story with electrical equipment. Pretty much anything you buy is designed to withstand voltages far in excess of nominal. Almost every

Voltage is only half the story with electrical equipment. Pretty much anything you buy is designed to withstand voltages far in excess of nominal. Almost every input on an electronic device will have "transient voltage supression" ESD protection diodes which will short high voltages to ground. This is generally because of static electricity. The potential difference between a person and ground can easily reach 5kV. Generally any device you buy today will have been tested to some sort of ESD standard - often to 8kV discharge voltage. Other tests done during electromagnetic compatibility testing (EMC) include bombarding things with radio waves, testing susceptibility to surge voltages and injecting voltages into power cables. https://emcfastpass.com/emc-testing-beginners-guide/emc-immunity-testing/ https://emcfastpass.com/emc-testing-beginners-guide/emc-immu... The key for all of these is duration and total energy. A TVS diode can deal with high voltages - but if they're sustained for too long the diode will burn up. The testing regimes all use quite low total energies. The values you give for geomagnetically induced currents talk about volts per km. EMC testing of industrial equipment is typically done at volts per meter - a factor of 1000x greater. The industrial standards require 10 V/m, military stuff is tested at 200 V/m.

theamk 4y ago
Right, and from my reading there is no strong EMC components in the solar storms. Radios are disrupted, but from ionosphere changes, not from jamming. it is mostly the weird GIE thing which is described as "quasi-DC", and also mentions "millions of amperes" So all that EMC stuff is very important in everyday life (and it killed more than one FET :) ), but seems inapplicable for Carrington-style event. There, it will be all about huge currents and low voltages. If the wire is long enough, TVSs may burn out, capacitors may overvolt and explode, any ESD protection diodes will also get destroyed. Luckily, we don't have a lot of long-distance copper wires connected to sensitive electronics.

theamk 4y ago

Right, and from my reading there is no strong EMC components in the solar storms. Radios are disrupted, but from ionosphere changes, not from jamming. it is mostly the weird GIE thing which is described as "quasi-DC", and also mentions "millions of amperes" So all that EMC stuff is very important in everyday life (and it killed more than one FET :) ), but seems inapplicable for Carrington-style event. There, it will be all about huge currents and low voltages. If the wire is long enough, TVSs may burn out, capacitors may overvolt and explode, any ESD protection diodes will also get destroyed. Luckily, we don't have a lot of long-distance copper wires connected to sensitive electronics.