Looking at the specs it says:
Min Grounding Conductor #8
with a footnote (4) size per 310.16
Why would they size the EG using 310.16?
Why do they call for the EG to be the same size as the current carrying conductors? Extra safty or a mistake?
I would say it should be sized per 250.122.
Also it lists the unit as:
Drawing 54 amps at rated output
Use #8 min input conductors
With the same footnot size per 310.16
If I look at 310.16 #8 is good for 55 amps if you could use the 90 degree column. In the 75 degree column it is only good for 50 amps.
I agree you can derate it for duty cycle per 630.11.
It does not list the duty cycle on this page. And still why would they say size per 310.16 with no mention of derating. Would derating the conductors per duty cycle be concidered by some as failing to follow manufactures instructions.
To me it just looks like the manufacture stumbled with the NEC when printing the manual.
