On 24 Dec 2016 at 23:32, David Nelson via EV wrote: > What is the actual sustained current carrying ability of the NEMA > L6-30 plug/sockets?
I may be proven wrong, but I don't think you're going to get a definitive answer to this question. The manufacturer and vendors will tell you it's 30 amps because for liability reasons they can't tell you anything else. I certainly wouldn't, and I don't even make or sell the stuff. You can of course run your own tests at higher currents to see how much heat builds up, but how can you know what long-term effect a particular amount of heat will have on the materials the recept and plug are made of? Besides, different plug and recept combinations have different amounts of resistance. That will change the amount of heat generated, so you'd have to run rather exhaustive tests. Also, as the recepts wear, contact tension falls and resistance increases; a new pair that stayed cool at 40 amps might not after 100 make/break cycles. The manufacturers have taken all these factors and more into account in rating their parts. NEMA 5-15s are allowed on home circuits protected at 20 amps IFF there is more than one such recept on the circuit (a duplex recept is considered 2 outlets). This implies that the reason is that the code makes this allowance because it assumes a significant chance (though not a certainty) that a full 20a circuit load will be distributed among multiple outlets. I've heard rumors for years that the 5-15 recept contacts are identical to 5- 20 contacts, but I have no way of confirming that. They might look the same, but be of different composition or have spring tension specification, or be manufactured to less critical tolerance, and thus might present different contact resistance, either when new or after some amount of use. Again, how can you be sure? The bottom line is that if you use electrical components beyond their specifications, you're taking a risk at some level. If you do this in a fixed installation, you're violating code. In most cities code carries the force of law. Violating it may also have an effect on your insurance coverage. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to "evpost" and "etpost" addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
