Can i connect 12/2 wire & 14/2 wire circuit into a junction box ? if not, how to do the connection.?

Question

Can i connect 12/2 wire & 14/2 wire circuit into a junction box ? if not, how to do the connection.?

Answer 1

Rephrasing my earlier answer. If you mean connecting both of them together in the same wire nut, then it depends which wire is connected to the breaker.  If the 12/2 is connected to the breaker, then there shouldn't be a problem.  If the 14/2 is connected to the breaker, then there might be a problem.  The reason is because which ever wire is connected to the breaker, it's going to have to be able to handle the TOTAL amperage of the circuit.  Assuming that the 12/2 is connected to the breaker, then whatever new load or loads your going to be using on the 14/2 wire has to be less than a TOTAL of about 15 amps to be safe.  You need to look at the amperage readings of your appliances and add them up.  If it only shows the wattage or VA on the nameplate then you need to use this formula to get the amps--Wattage or Va divided by volts=amps (1200watts or VA divided by 120volts=10 amps.  Next you need to watch out for overloading the entire circuit.  You can use the same method, or you can get an ammeter and measure the current around the wire going into the breaker.  But everything in that circuit needs to be turned "ON" in order for meter to read it.  Do not go over 80% of the breaker rating.  (Do not go over 16amps on a 20 amp circuit). NEC

Answer 2

You can extend a 14/2 wire with a 12/2 wire.  The 14/2 should be connected to the breaker box through a 15A breaker.  If you have a 20A breaker with 12/2 wire connected to it, do not extend the 12/2 with 14/2.  The wire could heat up before the breaker trips as 14 GA wire is not rated for more than 15A.

Answer 3

you just dont have enough info here

what size is the circuit breaker

what is the 12 running

what is the 14 running

what do yo me connect

which is the feed

which is feed out