On Wed, Mar 19, 2014 at 12:24:38PM -0400, William Herrin wrote: > On Wed, Mar 19, 2014 at 11:22 AM, Lamar Owen <lo...@pari.edu> wrote: > > Just replacing an L6-20P with an L6-30P on a 20A-listed PDU would be unsafe > > and (IMO) unwise, since the breaker in the input of the PDU does not protect > > the flexible cord's conductors from internal overcurrent faults. > > Yet an 18 awg PC power cable is perfectly safe when plugged in to a > 5-20R on a circuit with a 20 amp breaker. Get real man.
Not really, that is just a compromise in safety standards for convenience. It was deemed to be safe enough given the comparatively low current 20A circuit and the open-to-air power cord. For higher current circuits 30A and up, the safety standards are more stringent. > The NEC (and related fire codes) don't apply to supply cords of > appliances in circumstances such as OP's PDU. > > The modification cancels the UL certification. If you have an external > requirement to use only UL certified components then you can't make > any modifications no matter how obviously safe they are. > > By the way, you either don't have that requirement or you're breaking > it. Your custom network cables are not UL certified. There is more to safety than just being "certified". Acting in ways that /actually/ improves safety (if you are allowed to) is important. This isn't just black and white. Safety, like security, isn't absolute. Both benefit from defense-in-depth, and both require compromise to balance safety vs. convenience.