Tandem Breaker and Circuit(s)

whowadat

Hello, got a small basement remodel going on. Out of a Square D panel # QOC20U with a 200 amp service I want to add one circuit. This circuit would have 8 outlets on it, one outlet sporting a computer set up and another an entertainment center, the rest might get a lamp or something or not even used in a guest room.

There's four spaces free on the panel, with four other spaces filled by tandem breakers feeding 8 circuits in the house, and 6 double pole breakers using the other 12 slots. Future plans call for a 240V wall mount heater with fan, and a half bath in the basement.

I figure two spaces along one side of the panel will be filled by that 240V dedicated circuit leaving two open spaces on the opposite side. I figure that the use of a tandem breaker would be wise as this would still leave me an open spot in case I wanted to add another circuit(s) to the garage or something. I assume this tandem breaker could be used for all 8 outlets in one circuit leaving the other open for the future bathroom needs.

Question, should I purchase a 20 amp tandem breaker or a 15 ?? I'm assuming 20 amp but can the future bathroom light be plugged into a 20 amp circuit using 14/2 wire ?? (I assume I can just use 12/2 for the light)

I have noticed that some of the tandem breakers that are already installed have lights tied into their 20 amp circuit, is that a problem if 14/2 wire was used to connect the lights ?? (I'm assuming 14/2 is only to be used with a 15 amp breaker so this could be a potential problem)

Lastly, it seems a bit strange to me that all three bathrooms presently in the home are all tied into the same 15 amp circuit, along with all lights and sockets in the master bedroom and lights only in a second bedroom - seems like the potential for blowing this breaker is pretty high given that there's some ladies in the house using all knids of electrical mechanisms to doll themselves up in these three bathrooms. Best I know the breaker hasn't tripped but should some rerouting or changing of the breaker be considered - I assume if it ain't broke don't fix it.

Thanks in advanced for any replies!

kbsparky

FWIW, that catalog number is for the panel cover. I'd be willing to bet your actual panel is a QO12040M200. See if you can verify this.

I do not recommend using tandem breakers unless the panel is already full.

You can use a #12 wire for your lights. Do NOT connect a #14 wire for a lighting circuit to a 20 amp breaker. Code violation and safety hazard here, for sure.

See above. Time to change out the existing breakers to the proper size.

During prior code cycles, it was common practice for wiring to be installed as you have observed. If you begin to experience problems with overloads, then by all means consider installing some new circuits for those bathrooms. But, as you stated, if it ain't broke ....