Romex wiring

[Classic66s]

I am finishing an office in my basement and have never worked with Romex before. I always did the conduit and wire method. I installed outlets in an office I built and hooked the circuit to a hot line. When I checked the outlets they all said open ground except the last one in line and it showed correctly wired. That one has the ground wire connected right to the outlets grren screw. The outlets in between the correct one and where I hooked into the power all say open ground. I just twisted the ground wire together and continued down the line. I take it that is incorrect? Please advise.

[ameijers]

Um, lessee- you didn't use metal conduit, you didn't put the ground wire from each run under the romex clamp on the box (assuming it was a metal box), you didn't pigtail the ground off to the screw on all but the last outlet....

Where did you expect those outlets to ground TO? If you used the now-typical blue plastic boxes, those outlets are pretty well isolated from any ground path.

Go back to each box, undo the wirenut on the ground wire, add a pigtail to the green screw on the outlet, and reapply the wirenut. Assuming you got the polarity right on the outlets, your tester should show green lights.

aem sends....

[Colbyt]

Twisting them together is fine using a wire nut but there needs to be a pigtail connection to the green screw or the outlet remains ungrounded. The fact that the last outlet is grounded indicates you have otherwise proper connections.

Wire nut is required even on the bare wire as there should be no open ends of bare wire in the box. This may not be enforced in your area as crimp connectors have become more widely used.

Colbyt

[Member, Takoma Park Volunteer]

When wiring a box with Romex you leave ten inches of bare Equipment Grounding Conductor (EGC) to each cable. You wrap one around the box bonding screw and one around the grounding screw on the receptacle or other device and then you splice them together. If there are multiple devices in the box you splice a four inch pig tail or jumper for each device in with the EGCs and then connect the jumpers to the individual device grounding screws. The EGC from the power source is looped around the box bonding screw prior to the splice.

If you no longer have enough wire to loop then splice the EGCs from each cable to jumpers for each device and one for the box.

-- Tom Horne

[gfretwell]

Screw a green wirenut with a built in pigtail to each ground splice and connect that to the green screw. Easy fix for where you are. They have a bag of 5 at the Home Depot.

[buffalobill]

[Robertm]

I notice it says you must use lineman's pliers for twisting wires together. However, I've watched several electricians stick two wires into a wirenut and twist them together without twisting them together with pliers first. Other electricians do use the pliers first then slap the wirenut on. Is one method better than the other?

Bob

[Chris Lewis]

According to Robertm :

[I wrote the FAQ]

The real answer is follow the instructions on the box. There are some wirenuts these days that should not be pretwisted. If there are no instructions, twist the wires first with pliers - that is the standard way, unless the instructions tell you otherwise.