[TroyG]

I am switching a 4 prong cord for 3 prong cord as the house we just moved into has only 3 prong plug
I just want to make sure I have proper ground for this cord... it seems straight forward but the 4 prong cord I am removing does not look like it was installed very well... (nuts were loose) but dryer worked fine.

*I'm attaching a pic of how it was wired

QUESTION: can I just install 3 prong to this setup or do I need to attach seperste ground to outside ground screw? ... and if so, which wire should go to ground screw??

Any help is greatly appreciated... just want to be safe!

 

[jmon]

Your pic never posted. i have responded to your post, you should be able to upload it now.

 

[jmon]

As you have mentioned, it is pretty straight forward. Any homeowner can do it. Click on the link, scroll down and watch the 2 minute video.


https://www.thespruce.com/convert-4-prong-dryer-cord-to-3-prong-outlet-1821521

 

[Oldmaster]

I'd check the receptacle and see if a ground wire is available. If so you can change the receptacle and become code compliant.

 

[rjniles]

With a 3 wire dryer cord the center terminal is the neutral and must be connected to the frame of the dryer. Some dryers have a green wire to do this and some have a metal strap connected from the neutral to the frame. Show us a picture of the dryer terminals.

Sent from my RCT6A03W13E using Tapatalk

 

[DIYOkie]

As you have mentioned, it is pretty straight forward. Any homeowner can do it. Click on the link, scroll down and watch the 2 minute video.


https://www.thespruce.com/convert-4-prong-dryer-cord-to-3-prong-outlet-1821521

Good video for DIY'ers.

I was reading a bit of the article cuz I've always been curious exactly what the energized condition could be that would make neutral/ground sharing so dangerous.

However, clothes dryers are actually 120/240-volt appliances. This means that some elements of the dryer, such as the timer and light, operate on 120-volt current, while the heating element itself is powered by 240-volt current. The 120-volt, single-phase features of the machine require a true neutral pathway, so up until the 1990s, the solution was to jumper the neutral pathway into the ground wire. In other words, the circuit grounding wire served as the neutral pathway for the components that operated on 120-volt current. But it was soon recognized that this joining of the ground and the neutral opened the possibility that the metal frame of the dryer could become energized, posing a danger of shock.

I guess I could see if there was an open neutral in the machine, or where the cord connects, and then a hot wire was to touch the case, there would be no path to ground and no circuit breaker to break the circuit. Seems like that would be quite rare.

Are there other more common ways to cause the frame of the dryer to become energized but not trip a breaker?

 

[rjniles]

"The 120-volt, single-phase features of the machine require a true neutral pathway, so up until the 1990s, the solution was to jumper the neutral pathway into the ground wire.

This is not an accurate statement. A 3 wire dryer or range circuit has a neutral. What it does not have is an independent ground. The frame of the appliance is connected to the neutral to provide a return path for a ground fault. That is why a 3 wire dryer circuit must use an insulated wire as the neutral conductor.

 

[DIYOkie]

"The 120-volt, single-phase features of the machine require a true neutral pathway, so up until the 1990s, the solution was to jumper the neutral pathway into the ground wire.

This is not an accurate statement. A 3 wire dryer or range circuit has a neutral. What it does not have is an independent ground. The frame of the appliance is connected to the neutral to provide a return path for a ground fault. That is why a 3 wire dryer circuit must use an insulated wire as the neutral conductor.

And that frame-to-neutral path for a ground fault also presents a possibility for the frame to become energized. How is that possible if the breaker would trip?

 

[MTN REMODEL LLC]

Yes...Sorta but sorta backwards......if the frame gets energized, current will flow down the neutral and trip the breaker.

 

[Oldmaster]

Current on the neutral may not trip a normal magnetic trip breaker. Did you ever take a neutral off the bar and it sparked? Ever got a shock from s neutral? If something happened to the dryer and there was a significant load imbalance the neutral will carry that current. If it's grounded to the frame the frame may be energized.