Multiwire branch circuit

[kwired]

I most definitely can be mistaken, but after reading 240.15 a dozen times it appears you might not be able to use a handle tie on a 3 single pole breakers that feed line to line & line to neutral loads
(B-3 only mentions line to line loads on a 3 phase system)

Now read post 19 and it will straighten out any confusion

 

[augie47]

Now read post 19 and it will straighten out any confusion

My confusion has tom do with senility so one post probably won't solve the problem
then again, that might not be a fair thing to say as I tend to "read over" your posts.