Changing my 3-prong dryer outlet to a 4 prong (sanity check)

[slightlyoffbeat]

Hello everyone,

I have read all of the threads on 3 prong/4 prong. If I can't upgrade my outlet, then I'm just going to use PJ's advice and use a spa panel.

My situation:

I own my condo. I have a 3 prong dryer outlet:

The wires from the outlet run long the wall, over to the other side of the room to a box (just above breaker box):

And inside that box you can see the h/h/n wires, but also a copper wire that presumably runs to the breaker box.

So here is the question.

Can I simply buy some copper wire, attach it to the current copper wire in the box, run it to the outlet, and swap out the outlet for a 4 prong? My plan is to then have a 4 prong cord with GFI built in.

Thanks in advance for any advice that you might have. I have almost everything else down, but this is keeping me from moving forward.

Cheers.

 

[raouliii]

I would recommend opening the panel to verify but I'd bet that bare copper wire under the screw in the junction box is a good ground, which means you already have a 4-wire circuit. The metal conduit from the junction box to the 3 wire dryer outlet carries the ground to the outlet. Inside of the panel, (is that the main panel for the condo?), if the white wire is connected to the neutral buss (along with the other neutrals), and the ground wire is connected to the ground buss, then you're gold. A 4-wire outlet can be installed in place of the current 3 wire outlet. Just be sure to ground the 4-wire ground to the incoming conduit. Alternately, you can add a bare ground wire in the conduit out to the new 4-wire outlet. The second option would be my preferred option since the circuit ground would no longer depend on the conduit, the joints of which sometimes can loosen.

Be sure to turn off the associated breaker when fiddling with that outlet. Don't poke fingers or screwdrivers into the panel while the cover is off.

 

[williamsdm1111]

As a licensed electrician I agree. Just swap it out an make sure your new outlet is grounded to the conduit/box.

 

[P-J]

The conduit and its connectors appear to be plastic.Therefore, it does not carry ground. You need to pull a seperate groung in that case. You might have to pull the current wires out and then add the ground when replacing the bundle and reinserting the wires.

You might be better off and cheaper with the Spa Panel idea. (shrug!)

Just saying...

 

[raouliii]

The conduit and its connectors appear to be plastic......

Looks like painted EMT to me. The 90deg turn not having any joints as well as the set screws at the outlet and junction box are good indications of EMT.

If the conduit is plastic, I agree, a ground wire is necessary, not just prefered.

 

[P-J]

Look at the 1st and 3rd pictures for the conduit connectors. They are plastic not metal.

Big probem right there.

 

[AnOldUR]

 

[P-J]

Look closer at the image. What you pointed out is part of a knock out port.

 

[sennister]

No ground wire there. I can't tell if the conduit is plastic or painted metal from the pics.

However because it is conduit, worst case, you could pull a ground wire into the conduit and then you would know you are good

Keep in mind that if any of the parts are plastic you are out of luck. If they are all metal then you could ground to the box.

In my house with the exception of an addition that was put on in the early 90s which uses Romex, everything else is in conduit. Since the house was built in the early 60s that meant 2 prong outlets for all 110. On those I used a pig tail to ground to the box which is grounded to the conduit. All of it metal in my case.

 

[crazyirishman34]

Looks like EMT to me. I think what you are seeing as plastic is oxidized metal. Plastic uses solvent weld not screw connections.

 

[sennister]

Looks like EMT to me. I think what you are seeing as plastic is oxidized metal. Plastic uses solvent weld not screw connections.

Yeah I am thinking EMT as well. That is where I typically see those screw connectors as well. Got a magnet? Easy enough to check.

 

[DaleHair]

It is clearly EMT with die cast set screw connectors. It also looks like a ground wire just above the neutral wire near the center of the box. I would also add a copper ground wire in the conduit just for added safety in case the fittings work loose somehow.

 

[raouliii]

I've never seen a PVC electrical fitting with a set screw. Plastic or EMT, regardless I would add a ground wire from junction box to outlet. I see a bare ground screwed down to the lower center of the j-box.

 

[slightlyoffbeat]

Hello everyone,

Thank you for the replies! They are super helpful.

Just checked to help clear a few things up. The ground (from junction box) and neutral are wired correctly:

Everything is metal...except the connectors (checked with a magnet). So I'd need to run the ground wire or change the connectors.

So my two options are:

1. pull a copper wire through the conduit, and swap out 3 prong for 4 prong (I have a fish rod I can use for this).

2. Create PJ's Spa panel.

Both are safe and will work fine for a kas/EB clone from what I've read?

Thanks again everyone. This community has been a big help to me.

 

[crazyirishman34]

You should check continuity from the box to the ground bus. White metal isn't magnetic but it is a conductor. But if you don't have a good ground I would pull a ground. Much cleaner install.

 

[raouliii]

....Everything is metal...except the connectors (checked with a magnet). So I'd need to run the ground wire or change the connectors.....

Actually, EMT fittings are generally cast zinc, which is non-magnetic, so a magnet doesn't really determine whether they are plastic or metal. I've never seen a plastic fitting with a set screw.

.....So my two options are:

1. pull a copper wire through the conduit, and swap out 3 prong for 4 prong (I have a fish rod I can use for this).
.....

This is likely the easiest if you will be using a GFCI cord.

It appears the circuit includes a pair of twist connectors inside the panel. While they are not unsafe, in and of themselves, I would recommend checking these to make sure they are solid connections. Twist off the connector and make sure the wires are twisted firmly together. That goes for the connections in the junction box as well.

Again, de-energize the circuit and be careful in that panel.

 

[crazyirishman34]

Deleted Quote

I am a licensed electrician and have installed plenty of EMT. So I don't know were you get off

 

[slightlyoffbeat]

I want to thank everyone once again for the help.

I decided to actually test the continuity from the ground wire/junction box to the outlet. I did several tests and was pleasantly surprised to find that there was indeed continuity. So I purchased a new outlet for 10 bucks at HD, and used some spare copper/ground wire and the result is below. I tested the outlet with a multimeter and it all seemed to check out. I don't think there's any other way to test ground?