sub panel, two ground paths?
I have a sub in an out bldg. The neutral/ground bonding screw was removed with a dedicated grounding strip screwed to the cabinet and cabled to a copper earth stake. My cheapest and safest choice for a 50A service cable was 2-4 Al "mobile home cable." I could not buy 2-3 cable so I had a grounding conductor (green stripe) that I thought was not necessary. Untwisting that strand to get rid of it for over 80' of cable was not an attractive option.
A guy I worked with has a son who is a journeyman electrician so I tapped his brain. He said it is now considered okay to connect the grounding cable between the main breaker and sub cabinets as long as the sub has an earth ground, so that's what I did.
Everything I seen on the subject though forbids a grounding cable between a main and sub. Is there a revision on this?