multiconductor neutral

[The Archangel]

A very old house with a small panel would like to add a hot tub. As the existing panel is full, this will require the addition on a sub panel.
To accommodate to the new sub panel, two existing circuits will have to be relocated to the new sub panel.
THE PROBLEM: Every circuit is split, (left and right) and sharing a neutral. I.E. 1&2, 3&4, etc. So if you relocate circuits 2&4 in favor of the new two-pole to feed the sub panel, then the neutral that feeds them is also feeding circuits 1&3.
In which panel would they properly belong?

 

[LEO2854]

A very old house with a small panel would like to add a hot tub. As the existing panel is full, this will require the addition on a sub panel.
To accommodate to the new sub panel, two existing circuits will have to be relocated to the new sub panel.
THE PROBLEM: Every circuit is split, (left and right) and sharing a neutral. I.E. 1&2, 3&4, etc. So if you relocate circuits 2&4 in favor of the new two-pole to feed the sub panel, then the neutral that feeds them is also feeding circuits 1&3.
In which panel would they properly belong?

If you bring circuits into the sub panel the neutrals must come with them.

 

[John120/240]

A very old house with a small panel would like to add a hot tub. As the existing panel is full, this will require the addition on a sub panel.
To accommodate to the new sub panel, two existing circuits will have to be relocated to the new sub panel.
THE PROBLEM: Every circuit is split, (left and right) and sharing a neutral. I.E. 1&2, 3&4, etc. So if you relocate circuits 2&4 in favor of the new two-pole to feed the sub panel, then the neutral that feeds them is also feeding circuits 1&3.
In which panel would they properly belong?

If I understand your description, You say left & right, 1 & 2. If the odd numbers are one buss & even numbers are the other buss by your description you don't have a MWBC (multi wire branch circuit) You have two circuits fed by the same phase which will overload the neutral.
Is the wiring method Romex ? If so to be a MWBC then you have black, white, red, bare in one Romex jacket.
Others will chime in to hopefully decipher your problem.

 

[electricalist]

1 and 2 should not be sharing a neutral..
1 and 3 could. The neutral being shared by 2 breakers on the same phase should be checked..

 

[kwired]

I think OP is saying breakers in positions 1,2,3 and 4 all share a single neutral conductor, if so he has some problems as nothing he will do outside of redoing the portion of those circuits that shares this common neutral will be code compliant, it wasn't right to begin with.

 

[don_resqcapt19]

Not all panels stagger the neutrals vertically. A push-a-matic panel has one ungrounded conductor for all of the left side breakers and the other ungrounded conductor for all of the right side breakers.

 

[kwired]

Not all panels stagger the neutrals vertically. A push-a-matic panel has one ungrounded conductor for all of the left side breakers and the other ungrounded conductor for all of the right side breakers.

And would still have same loading effect on a single neutral shared between positions 1 thru 4.

But if that is what OP has he wouldn't be adding a 120/240 feeder to positions 2&4 either.