I am installing a light on my new lamp post. The electrician left a junction box with red, black, white wires and a ground wire. I ran black,white and ground wire romex through my conduit that was left to easy connect the light to the house wires. So my question is...i connected mu black fixture wire to black wire from romex and white fixture wire to white romex wire. Inside the house i am now unsure how to connect the black romex wire to the box. The box has red, black and white. I've connected white to white and black to black and this caused my breaker to break. I then connected romex black to red and left white with white and this blew my circuit as well. Help

 

Romex is a brand name for type NM cable. Type NM is NOT listed for use outside or underground, even when in conduit. Also, cable (more than one conductor in a factory assembly with outer sheath) is not recommended to be installed in conduit except when needed for physical protection. You would be far better to use type THWN individual wires for the conduit run.

As for the problem at the junction box...without knowing how the electrician hooked things up I can't help.

 

Romex can not be used for outside wiring. Outside you would use UF cable but for conduit that is continuous best practice is to use individual wires such as THWN not cable. You should run correct wiring to the post light before proceeding.

Are there any other wires in this box? How did you wire the light? Your description of a red white and black wire seems odd. Is this part of a 3-way switching circuit. Are you sure it was intended for this purpose?

 

My general contractor had the electrician put a pvc pipe through my foundation under the ground and it ran underground all the way to the part of my yard where light post was to be installed. I went to home depot and bought wire to run through the pvc pipe to connct to the junction box my electrcian has wired. I bought the wire based on recommendation of gentleman helping me in home depot.

The wire i ran through the pvc pipe has a black, a white and a ground wire and it is encased in sheathing. It may or may not be romex - to be honest i am not sure.

I connected the light fixture wires to the wire running through the pvc pipe in the following way, black to black, whiTe to white and ground to ground.

The wire coming out of pvc pipe in my basement now needs to be connected to the box that the electrician wired which is connected to a switch that will hopefully turn my light post on and off.

My question still remains, the box has a red wire, a black wire and a ground wire but the wire that is connected to my fixture only has a black, white and ground wire.

So i did the following, i connected the red wire to the black fixture wire, then connected the white to the white and ground to the ground wires - when i turned on the switch, it caused my circuit breaker to break. I then disconnected everything and started again, connecting black fixture wire to black box wire, then white to white and ground to ground wires, this also caused my circuit to break.

Hope this detail helps. Still not sure what the problem is. Thanks

 

What color is the sheathing? What size are the wires in it? What is imprinted in the sheathing?

How is the switch wired? how many wires are connected to it and what color is each?

Is there only one 2-wire cable - black, red, white and bare wires - plus the cable you fed to the post light in that box? No other cables or wires?

Did the cable slide smoothly when you pulled it, or did it bind and require a stout tug to free it up?

Pictures of the connection at the post light, the J-box, and the switch and switch box might help. See How To Include Pictures.

 

The wire i bought and ran through the pvc pipe has a yellow sheathing and it says romex awg12 cu 2 cdr with awg 12 ground type nm- b 600 volts

I have not looked at the wiring for the switch yet

The cable slid smoothly through the pvc pipe

The box the electrician installed had a similar looking romex type cable coming in the back and it is cut open revealing a red, black and ground wire with a nut on the red and black wires. I pushed my romex cable through the back of the box and am now trying to figure out which wiresnto attach to which. Thanks

 

That would be cable not wire and it is the wrong kind of cable. It needs to be replaced with the correct kind of cable or if a junction on both ends of the conduit the correct wire. Depending on the breaker size you need either #12 or #14 UF-b cable or depending on breaker size either #14 or #12 THWN type single conductor wires, one, black, one white, one green (or bare).

Is the conduit connected to the box? How and where does the conduit terminate at the light?

First you need to remove what you have because it is unsafe and replace with correct cable or wire.

Tech notes: Wire is individual conductors. Cable is two or more conductors in a sheath. Wire (or cable) size is determined by breaker size. Minimum for a 15 amp breaker is #14. For a 20amp breaker is #12.

 

The cable i have in place is the cable that i would like to use given the post is set in place and everything is really at it's end. Can i get something done with the cable that is installed?

 

For your installation to be code compliant and safe, you need to remove the Type NM cable that you installed in the outdoor conduit. If you don't have a weatherproof junction box at the post light, you need to run Type UF-B cable in the conduit. If you do have a weatherproof junction box at the post light, you can run individual strands of Type THWN to that. Once that is done, your other questions can be addressed.