View Full Version : New 250 volt circuit, no grounding bar in main panel
skinsew
Jul 3, 2007, 08:05 PM
Hi, I have searched for this answer but I can't find a clear answer for a rookie. I am adding a 250v/20amp circuit to my main panel for a window air conditioner. I have a newer Murray main panel that was installed by an electrician, but its an old house and all the outlets are 2 prong type. So I am looking in the main panel and I see the neutral bar, with all the white wires and one bare copper wire attached to it, but no ground bar. To install the circuit, I have a new 250v/20amp dual circuit breaker I am going to install using two slots in the main panel. I am going to run wire from a 20a/250v , 2 pole 3 wire receptacle to it. Do I hook the black wire to one of the brass screws of the receptacle, the white wire to the other brass screw (and label it with red tape) and a copper wire to the ground terminal of the receptacle, then hook the black and white wires to the 2 terminals on the circuit breaker and the copper ground wire to the neutral bar, since I don't have a ground bar in the main panel?
Thanks
canbeefixed
Jul 3, 2007, 08:44 PM
Hi, I have searched for this answer but I can't find a clear answer for a rookie. I am adding a 250v/20amp circuit to my main panel for a window air conditioner. I have a newer Murray main panel that was installed by an electrician, but its an old house and all the outlets are 2 prong type. So I am looking in the main panel and I see the neutral bar, with all the white wires and one bare copper wire attached to it, but no ground bar. To install the circuit, I have a new 250v/20amp dual circuit breaker I am going to install using two slots in the main panel. I am going to run wire from a 20a/250v , 2 pole 3 wire receptacle to it. Do I hook the black wire to one of the brass screws of the receptacle, the white wire to the other brass screw (and label it with red tape) and a copper wire to the ground terminal of the receptacle, then hook the black and white wires to the 2 terminals on the circuit breaker and the copper ground wire to the neutral bar, since I dont have a ground bar in the main panel?
thanks
Yes you have that all figured out.hopefully your receptacle is of a different pin configuration ,then any of your 110/120 volt receptacles. One of the spades in the receptacle should be a sideways one
skinsew
Jul 3, 2007, 09:20 PM
Hi, I have searched for this answer but I can't find a clear answer for a rookie. I am adding a 250v/20amp circuit to my main panel for a window air conditioner. I have a newer Murray main panel that was installed by an electrician, but its an old house and all the outlets are 2 prong type. So I am looking in the main panel and I see the neutral bar, with all the white wires and one bare copper wire attached to it, but no ground bar. To install the circuit, I have a new 250v/20amp dual circuit breaker I am going to install using two slots in the main panel. I am going to run wire from a 20a/250v , 2 pole 3 wire receptacle to it. Do I hook the black wire to one of the brass screws of the receptacle, the white wire to the other brass screw (and label it with red tape) and a copper wire to the ground terminal of the receptacle, then hook the black and white wires to the 2 terminals on the circuit breaker and the copper ground wire to the neutral bar, since I dont have a ground bar in the main panel?
thanks
Thanks, Yes, the receptacle is the sideways type. What type of wire would you recommend I run? Its only a 20 foot run from main panel to the receptacle box. I was thinking the 12 gauge 3 wire is just fine, but you guys are the experts and I don't want to burn my house down:)
Missouri Bound
Sep 20, 2010, 05:31 PM
A 20 amp circuit requires #12 wire in most installations. Which receptacle does your A/C require? Is it a 6-30r?
stanfortyman
Sep 20, 2010, 07:17 PM
Miss, did you check the date of the post you are replying to? :cool: