Need help wiring this 15A 120V GFCI outlet in existing circuit ???

I have a 20A double pole breaker circuit with 12-2 wire ..(total 3 wires including ground) .and currently only one unit is connected to end of this circuit which is fan baseboard heater.

I want to add an GFCI outlet which is 15A 120V

How do I wire this new outlet in to this circuit?

I will put this new outlet in to metal box with weather protection cover as its on exterior wall.

Thanks in advance.

For starters you will want a 20 amp gfi and the new wire will be #12

You can't. Being a double pole breaker with 12/2 wire I think you have a 240 volt heater. You can't use that circuit for a 120 volt anything.

vikasintl said:

I have a 20A double pole breaker circuit with 12-2 wire ..(total 3 wires including ground) .and currently only one unit is connected to end of this circuit which is fan baseboard heater.

I want to add an GFCI outlet which is 15A 120V

How do I wire this new outlet in to this circuit?

I will put this new outlet in to metal box with weather protection cover as its on exterior wall.

Thanks in advance.

Click to expand...

As JoeD has already said you cannot supply a 120 volt load from that circuit as presently wired. That is because, as presently wired, the circuit does not provide a Grounded Current Carrying Conductor (Neutral) to which one side of the new receptacle must be attached. That is why the terminal screws on one side of the receptacle are silver in color. The silver and brass colored screws show which side is for the energized conductor and which side is for the neutral.

There is a small chance that you can still get what you want. If you can readily rewire the heater to run on 120 volts AND once the heater is rewired it does not draw more than Ten Amperes or 1200 watts then you could make the change in the connections and proceed. The reason for the current limitation is that an appliance, such as a heater, which is fastened in place must not draw more than fifty percent of the ampacity of the circuit which supplies it if that circuit also supplies other loads; in this case your added outdoor receptacle circuit. Any appliance which is fastened in place must be supplied from a dedicated branch circuit if the appliance will draw more than half of the power that is available from that circuit.

If the heater that is already in place cannot be rewired to run on 120 volts or it draws more than Ten Amperes when wired for 120 volts AND it would be extremely difficult to run new conductors to the location of the outdoor GFCI, then you many even want to consider installing a smaller heater which will draw less than Ten Amperes at 120 volts.

You will also need to have enough slack in the cable to the heater that you can divert it to the GFCI outlet box and then jumper to the wiring compartment of the heater. Most heater wiring compartments are two small to use as a junction box so the heater's laboratory listing will not permit the wiring compartment to be used that way. The NEC requires that all installed electrical equipment must be used in compliance with it's listing and labeling.