How To Connect A 4-Prong Dryer Cord To A 3-Prong Outlet?

When you move to a new house, the outlets will be mostly 3-prong. But you have been using a dryer with 4-prong cords. So, what should you do to fix up your dryer? That’s what we will share today. 

To fix a dryer with a 4-prong cord in a 3-prong outlet, use a 4-prong to a 3-prong adapter where you connect the cord to one end of the adapter, and the adapter’s other end goes to the outlet. Other alternatives are changing the 4-prong cord to a 3-prong or installing a 4-prong outlet. 

Even though you can use adapters, it is risky. That is why most people recommend cord conversion. This guide will explore the possible ways of connecting a 4-prong dryer cord to a 3-prong outlet with some safety considerations. 

Check out our list of top-handpicked products for all your electrical, appliance, and HVAC system needs to keep your home running smoothly.

This post includes some affiliate links.

Understanding the difference between the 3-prong and 4-prong dryer cord

Due to the National Electric Code changes in 1996, the experts recommend wiring the electric dryer outlets from 3-prong to 4-prong. 

Before the change, people used to use 3-prong outlets and cords. 

This connection did not have a dedicated grounding. One out of the three prongs was used as either a neutral or a grounding connection. 

The 3-prong dryer cord will contain 3 hookups for 3 wire connections- two hot and one neutral/ground. There will be no separate ground wire. 

On the contrary, a 4-prong cord will have 4 wire connections – two hot, one neutral, and one ground wire. 

The ground connection is a separate return path for unused or extra power that flows during a short circuit. 

It eliminates the hazard of ground current to the appliance. 

Additionally, a 4-prong dryer cord is wired for 120V and 240V circuits. 

The 120V service will operate the dryer’s timer and sensor, and the 240V will operate the heating components. 

If you want to buy a 3-prong or a 4-prong cord for your dryer, here are two good options:

The dangers of improperly connecting a 4-prong cord to a 3-prong outlet

You do not connect a 4-prong cord directly to a 3-prong outlet. 

In a 3-prong outlet, you won’t get to plug in the extra prong in the cord. 

So, you either use an adapter, convert the prong to a 3-prong cord, or change the outlet. 

If you make mistakes in the wiring processes, there could be a high chance of short circuits and fire hazards.

The older electrical systems do not have a separate ground pathway. So, improper wiring will cause shocks and electrical accidents. 

Wrong wiring connections could accidentally connect the ground wire to the hot or neutral wire and create short circuits. 

The dryer’s metal will be connected to the hot wire. 

You will be shocked or killed if you touch the metal after the grounding connects to the hot connection.

So, be careful while wiring them, especially when using adapters. 

The need for a 4-prong to 3-prong adapter

CircleCord NEMA L5-30P to L14-30R Adapter Cord, 3 Prong to 4 Prong Generator Transfer Switch Adapter, 30 Amp Generator Twist Lock 3 Prong to 4 Prong House Inlet Box, STW 10 AWG Blue, ETL Listed

A plug adapter, also called a ground plug or pigtail adapter, is a common accessory that helps plug a cord into a different outlet. 

A 4-prong to 3-prong adapter enables to connect a 4-prong cord to a 3-prong outlet.

One side will have four slots to fit the 4-prong plug cord. 

The other side will have three prongs to get hooked in the 3-prong outlet. 

One end will be hooked with the 4-prong plug, and the other in the outlet. 

At the bottom, there will be a round metal loop or a green pigtail wire with a metal connector. 

Using these adapters with old household outlets that do not have 4-prong outlets is very common. 

In most cases, the old electrical systems won’t have a ground pathway. 

As a result, electrical shocks will occur if you use a 3-prong outlet in the systems via the adapter. 

Though one connection in a 3-prong is used as a ground or neutral, it doesn’t guarantee the grounding.

The 4-prongs have a separate grounding. 

A proper ground connection is safe and needed by the code for all the new constructions. 

Are Adapters safe?

According to a theoretical kernel of truth, adapters are considered safety devices to make such connections. 

But in reality, they do not provide any safety function. 

The reason is that some houses have metal boxes and conduits in their electrical systems. 

If not tampered with, the adapter provides enough grounding path running from the cover-plate screw to the metal strap on the outlet, metal box, conduit, and back to the main panel where the ground wire extends to the ground. 

For reasonable functioning, screw the little metal tab or the adapter’s green pigtail into the outlet’s cover plate. 

The adapter can lead to serious electrical problems if anyone tampers with the system.

If you have a plastic wall box, the adapter won’t do anything because there won’t be any continuous metal path back to the service panel. 

Even if you have a metal box, it won’t guarantee the ground’s path. 

Be careful while choosing the adapters.

There are adapters for welders or other 240V appliances. 

You can use them for a dryer outlet, but they won’t suit the appliance.

The plugs will look similar but won’t fit the dryer cord unless it is specifically made for the dryers. 

They must have NEMA designation of 10-30P and 14-30R. 

How to plug in a 4-prong to 3-prong adapter?

DEWENWILS 4 Prong to 3 Prong Dryer Plug Adapter, NEMA 14-30R Male to 10-30PFemale STW 10-AWG Electric Dryer Connector Cord, 30Amp/250V/7500W, 1.5 FT, UL Listed

It is discussed in brief earlier, but this section will share the plugging in a bit more detail:

  • Plug the 4-prong plug from your dryer into the adapter’s plug with 4 slots. 
  • Plug the adapter’s 3-prong end into the 3-prong outlet. 
  • Take the grounding pin into the dryer’s outlet in the house.
  • If you do not have any household outlet, use a heavy-duty metal clamp to clamp the grounding pin to a nearby metal pipe.
  • You may also use an adjustable galvanized hose clamp to connect the grounding pin to the nearby metal pipe. 
  • Use a screwdriver and tighten the clamp over the pin. 
  • You can remove the pin and connect a 10 to 12 AWG ring terminal. Use a self-drilling metal screw and attach the ground wire to your house’s metal frame part. 

The importance of ensuring proper grounding when using a 4-prong to 3-prong adapter 

While using adapters, you should ensure the grounding while using the adapter. 

Without enough grounding, you risk electric shocks and short circuits.

For proper grounding in the old 3-prong outlet, install a new circuit cable with the ground wire and then connect it to the outlet. 

While connecting the plug adapter to the dryer cord and the outlet, ensure that the grounding pin is inserted fully. 

If the pin remains partially inserted into the outlet, your dryer will not be grounded. As a result, you may face deadly electric shocks during operation or short circuits.

You can replace the old one with a GFCI (Ground Fault Circuit Interrupter). 

It will keep you safe from short circuits and electrocution by tripping whenever it senses an electrical issue. 

However, the GFCI won’t provide you with safe ground connections. 

To check for the grounding, plug in an outlet tester or receptacle tester. The device will inform you about the outlet’s grounding and other issues, like the hot and neutral reversed. 

Some LED lights will light up with different lighting patterns to let you read and inform you about the problems. 

Some adapters will have an extra ground wire. Plug that wire into the ground hold of the nearby outlet for safety purposes. 

Alternatives to using a 4-prong to 3-prong adapter

Many people do not recommend using a 4-prong to 4-prong adapter due to safety purposes. 

In that case, change your dryer’s 4-prong cord to a 3-prong cord to fit it in a 3-slot outlet. 

Another option is to change the outlet from a 3-prong to a 4-prong, which an electrician can only do.

Converting the cord from a 4-prong to a 3-prong is the easiest option, and most DIYers pursue this process when they face issues with cord and outlet match.

Things required:

  • Voltage tester
  • Magnetic nut driver
  • Pliers
  • Screwdrivers
  • UL-listed 3-prong dryer cord with strain-relief clamp

Step 1: Turn off the power

Locate the double-pole circuit breaker at the main panel controlling the cloth dryer. Flip it to the OFF position. 

At the dryer outlet, check the power with a voltage tester. 

Unplug the dryer and remove it to access the back panel.

Disconnect the dryer vent, too, before working with the dryer. 

Make sure to have enough light while working. 

Maximum dryers will have a 30 amp breaker stamped 30 over the switch bar. A double-pole breaker will be wider than a single-pole.

Step 2: Disconnect and remove the dryer’s electrical connection cover

Remove the cover with a screwdriver on the electrical connection at the dryer’s back. 

It will be above the power cord from the dryer and attached with 1-2 screws.

Keep the cover and screws aside. 

Step 3: Disconnect the electrical cord

Detach the strain-relief clamp holding the cord by unscrewing the screws that connect the 2 halves of the clamp in place. 

Separate the clamp halves and pull them out one by one. 

Detach the black and red cord wires with a magnetic nut driver from the life and right side of the terminal block. 

These two wires are the hot connections. 

Now, disconnect the white neutral wire from the central terminal and the green grounding from the machine case by unscrewing the green screw. 

Take the 4-prong cord out of the connection box. 

Step 4: Jumper the neutral to the ground

A 4-prong cord contains separate neutral and ground connections and two hot connections. 

A 3-prong will have two hot and one neutral or ground connection. 

To make this connection, connect the dryer’s neutral terminal to the ground case with a jumper’s help.

Find the white machine wire connected to the neutral screw terminal at the center. 

Disconnect this wire and reconnect it under the green ground screw tightly. 

Some dryers will have a metal bonding strap connected under the ground screw instead of the white machine wire. 

If you have a strap, attach the strap to both the ground screw and the neutral terminal. 

Step 5: Connect the 3-prong cord

Thread the loose end of the 3-prong cord through the electrical box’s hole and connect the 2 outer hot wires on the cord with the 2 outer terminals in the dryer. 

Put one of each screw.

Connect the center wire to the center terminal. 

For a grounding bonding strap, connect it to the neutral terminal with the center cord wire. 

Tighten all the wire connections properly.

Step 6: Install the new strain-relief clamp

Slide one-half of the strain-relief clamp inside the hole under the cord wire and the other half on the top of the cord.

Press the 2 halves with pliers and thread the screws in the holes. 

Tighten and secure the screws. 

Avoid reusing the original strain-relief clamp with the new 3-prong cords. 

Clamps for 4-prongs are round and, therefore, won’t fit the flat-shaped 3-prong cord. 

Use the strain-relief clamp given to you with the new 3-prong cord, or buy a compatible one separately. 

Step 7: Plug the dryer

Reconnect the connection box cover plate and screw back the screws tightly. 

Slide the dryer back to its place, and put back the dryer vent duct. 

Plug the cord inside the outlet.

Turn the dryer’s circuit breaker to the ON position at the main service panel and test turn on your dryer to check the functionality. 

The legality of using a 4-prong to 3-prong adapter

A 4-prong to the 3-prong adapter is only safe if the product is listed in UL (Underwriters Laboratories). 

The UL checks and encounters the product’s outcome by using it themselves before confirming its safety and usage. 

If the product is not UL listed, it means the adapter did not meet the safety regulations of the National Electric Code, or NEC. 

That is why most people consider changing the outlet or the cord.

If you choose to use a 4-prong to a 3-prong adapter, follow the directions suggested by an expert. 

Instead, hire an electrician for connection. 

The ground is used as a neutral connection when you use a 4-prong to a 3-prong adapter. 

Since the change in 1996, such a setting has been considered illegal, and that is why most adapters won’t have the UL label. 

It further raises liability which a few companies dare to take. 

If you take this risk, you connect the neutral to the ground inside the adapter. It is again illegal outside the dryer under the law. 

If you use it, use it at your own risk.

Since UL listed 4-prong to 3-prong adapters are hardly available, you may have to spend hundreds of dollars to receive one. 

Instead, changing the 4-prong cord to a 3-prong is easier and safe.

Maintenance and safety tips for using a 4-prong to 3-prong adapter 

The 4-prong to 3-prong adapters are made to safely use older electric appliances without changing the outlet or cord configuration. 

While choosing to use adapters, you must follow a few safety rules:

  • Always check the product label to verify the UL-listed certification. The product may not meet the NEC’s rules and regulations if the adapter is not UL-listed. 
  • It is better to consult an electrician before you use the adapter. Call an electrician to plug the adapter into your dryer’s cord and outlet. If any extra settings are needed, they can do it. 
  • Ensure that a 4-prong to 3-prong adapter has a separate ground wire running from the dryer’s chassis to the grounding rod. 
  • Make sure the grounding connection is properly made. You must install a new circuit cable with the ground and connect it to the outlet. 
  • While connecting the adapter, insert the ground pin fully into the outlet for safety. If your adapter has an extra ground wire, plug it into a nearby outlet’s grounding. 
  • While working, unplug your appliance and turn off the dryer’s power at the main panel. Avoid working around wet areas and wear protective gear for safety purposes. 

Final thoughts 

You can connect a 4-prong dryer cord to a 3-prong outlet only with the help of an adapter. 

You connect the 4-prong dryer’s cord at one end of the adapter and the adapter’s other end to the 3-prong outlet. 

Before choosing this option, make sure that the adapter is UL-listed. Otherwise, it will be illegal and unsafe to use.

The other alternative to an adapter is to convert the 4-prong dryer cord to a 3-prong dryer. 

The main difference in both prongs is the grounding connection. Though the 3-prongs were changed to 4-prongs after 1996, many houses have 3-prong cords and outlets.

A 4-prong contains a separate neutral and ground connection with two hot wires, and a 3-prong contains only two hot and one neutral or grounding.

Follow the maintenance tips if you choose to use an adapter. 

A lot of people do not recommend adapters. If you are using one, do it at your own risk. 

Can I change a 3-wire outlet to a 4-wire outlet?

Without running a new wire, you won’t be able to change a 3-wire outlet to a 4-wire one. Besides, you cannot do it yourself. You can change the cord instead as they are easily available and the task is simple.

Do I need to use a #10 gauge wire if my dryer already has a ground strap?

If your dryer already has a ground strap, you do not need to use any wire. Using the ground strap is simpler than using a wire.

What to do if my dryer sparks after changing the cord or using the adapter?

You should not receive a spark if you have followed the methods correctly. You may have mistakenly swapped a hot wire with a neutral one. If you hesitate, turn off your appliance and call an electrician to get it checked.

Reference: Plugs and sockets wikipedia

Sharing is caring!

Arthur Smith

Howdy! I am Arthur Smith, an electrical engineer who is extremely passionate about electronics. I have lived in different parts of the US and currently reside in Wisconsin. I am one of those rare children who knew what he wanted to study and do in life right from the start. I was a curious child who wanted to know how switches work and how the AC works, and I would always observe my dad whenever he would handle the wires and fix things around the house. I currently work as an electrical engineer at a reputed company and write for this blog. And I read loads of books or play video games in my free time.

Leave a Reply

Your email address will not be published. Required fields are marked *

Recent Posts