stjohnbarleycorn
Senior Member
A question came up about when the full sized ground with romex came in. Was it 65 or 71? thanks
1968 was the year that the EGC table 250-95 (now 250.122) took the shape that it is in today .........
So what you are saying is that it might have been in use before it was actuallly in the code?
In 1965 15 amp circuits weren't listed, 20 amp circuits were protected by #16 cu if in a cable assembly, 30 amp by #14, 40 amp by #12, and 60 amp by #10.
Prior to that, and back through the 1947 NEC, a reduced-size ground was only allowed as part of an approved cable assembly.
Wow. 60A on #10 seems ridiculous. What changed, though? Electrons just didn't decide to run a little hotter in the past 45 years...did they?
No, sorry that I was unclear. Just the EGC size fo a 60 amp circuit allowed at that size (#10), same as now. But the smaller amperage OC sizes allowed smaller EGCs than today.
For 20 amp circuits, sure. But look again for that asterisk location .... 30 amp?![]()
I'm not following you. I see 15a circuits with a 16 ground, and 20 & 30s with a 14.
Prior to that, and back through the 1947 NEC, a reduced-size ground was only allowed as part of an approved cable assembly.
Just responding to
Depends on what you/we mean by reduced-size. I was thinking 'compared to today'. So a #14 EGC for a 30 amp OCP branch-circuit is reduced-size, to me. But allowed in earlier cycles whether or not in cable. Only the #16 EGC for a 20 amp circuit needed to be in an approved cable assembly (1959 example, anyway).