The last guy got the 2-pole breaker thing right, the amperage wrong, and the GFCI wrong. Here's what you need.
The breaker needs to be correct for the smallest wire in the circuit. If it's all 12 AWG (no 14 AWG extensions) then the breaker must be 20 amps or smaller. A 30A breaker is wrong and should be removed from service immediately.
Since it's a multi-wire branch circuit (MWBC), the circuit needs common shut-off, and with circuit breakers, that means either a 240V/2-pole breaker, or single breakers with handle-ties. A handle-tie is a bit of plastic that sits in between the handles so they jointly shut-off. It's sold by proper electrical supply houses; Big Box won't stock it.
Since it's a bathroom, at least part of the circuit needs to be GFCI protected. Single-pole GFCI breakers with handle ties won't work. The only options are:
- A 2-pole, 120/240V GFCI breaker (expensive)
- GFCI receptacles, making sure if you connect any additional loads on the "LOAD" side of the GFCI receptacle, that they use a dedicated hot-neutral pair separate from the MWBC shared neutral.
One throw too far
Your meter-main was designed to use a set of smaller sub-main disconnects instead of a single main disconnecting means, in accordance with NEC 230.71:
230.71 Maximum Number of Disconnects.
(A) General. The service disconnecting means for each
service permitted by 230.2, or for each set of service-entrance conductors permitted by 230.40, Exception No.1,
3, 4, or 5, shall consist of not more than six switches or sets
of circuit breakers, or a combination of not more than six
switches and sets of circuit breakers, mounted in a single
enclosure, in a group of separate enclosures, or in or on a
switchboard or in switchgear. There shall be not more than
six sets of disconnects per service grouped in any one location.
For the purpose of this section, disconnecting means
installed as part of listed equipment and used solely for the
following shall not be considered a service disconnecting
means:
(1) Power monitoring equipment
(2) Surge-protective device(s)
(3) Control circuit of the ground-fault protection system
(4) Power-operable service disconnecting means
(B) Single-Pole Units. Two or three single-pole switches
or breakers, capable of individual operation, shall be permitted on multiwire circuits, one pole for each ungrounded
conductor, as one multipole disconnect, provided they are
equipped with identified handle ties or a master handle to
disconnect all conductors of the service with no more than
six operations of the hand.
However, the pair of single pole breakers in the lower-right that the inspector complained about means that you need 7 breaker throws to turn all the power off, which is one too many.
Evict the aliens!
Furthermore, the culprit breakers are a violation by themselves as they are GE THQLs, which are not listed to go in an Eaton BR panel. At this point, you might as well get a BR220 from the nearest supplier and have it slapped in in place of the culprits, killing two violations with one fix.
And yes, a two pole breaker can feed two completely separate 110V circuits
There is nothing in the NEC that prohibits a two pole breaker from feeding two independent branch circuits from the opposite legs it provides.
Best Answer
12 spaces is OK for this, but 20 or 24 spaces would not be out of place
A 12 space panel is a bit small, but OK for this job, given that you'll be using main lugs here. I would upsize to a 20 or 24 space unit though if at all possible -- as Harper said, "Spaces are cheap, regrets are expensive."
I'd stay in the BR line, however
Whoever recommended you a GE panel, though, was silly, and that breaker P/N isn't even a valid Eaton part number! (The correct Eaton P/N for a 50A two-pole breaker for that panel is CL250, BTW, and the corresponding native GE breaker for that would be a THQL2150.) I'd just get something like a BR2424L125G for this (provided it's indoors -- the outdoor counterpart is a BR2424L125R, but you'll need to field fit the grounding bar yourself in that case).
Don't forget the details
Make sure you pull the bonding Z-strap in the new subpanel, and also torque all the panel and breaker lugs to manufacturer's specs with an inch-pound torque wrench!