Double tap

Is a double tap acceptable on a main ground lug? One ground wire was for the main panel and the other for a 100 amp sub panel. Is there any information that covers this from the NEC?

Also, I am familiar with Square D QO breakers but I believe this one is double tapped?

Both lugs are not rated for the use of two conductors. Square D breakers allow for a double tap, but not tandems.

You’ll find your reference in here.

Should not be two conductors. And hard to tell, but the one with multi-strand conductor looks like maybe some some strands are cut… but difficult to tell for sure.

Also looks like the white stripe conductor may have been added a later date as it doesn’t have paste on it like the others.

What is your point? It is not required.

The paste would not make it right.

It’s still double lugged.

My point was what I stated Jim. Read.

As stated by others a code violation, the code reference is in Kenneth’s link in post #3. Just my 2 cents, when possible for clarity try to avoid using the term ground wire which is too ambiguous to really explain the conductor’s function. In the photo you have a black wire with a white stripe which is more likely to be a grounded or neutral conductor.