NEMA Config: Everything You Should Know About Finding a Suitable NEMA Connector

Are you having problems finding the right configuration for your connectors, plugs, and receptacles?

The National Electrical Manufacturers Association classified all products for easier navigation.

So, all it takes is to find a suitable NEMA config.

Then, check out our guide to discover adequate combinations and avoid potential issues!

Get Your Free Sample!

Enjoy a free sample worth UP TO $100!
Explore our custom services now. Email us at [email protected] for more details.

1.NEMA ConfigNEMA Connector Basics

NEMA connector outlet socket illustration

Caption: NEMA connector outlet socket illustration

A NEMA connector is a plug and receptacle approved by this association.

Therefore, you’ll mostly find it in North America.

The initial requirement is understanding the difference between specific units.

So, check out the terminology explanations below:

 Box Mounted and FlangeCord Mount
Female Connector – connecting to an electricity sourceReceptacle – Another name for this unit is an outlet. It’s a wiring device with a female flange mount. Furthermore, you’ll notice the mating surface hides conducting elements.Connector – This is another product connected to the power source. It has a similar construction to the receptacle.
Male Connector – connecting to loadInlet – This device has exposed conducting elements.Plug – You should never connect it to make the pins live when unplugged. So, always keep the plug dead until entering it into an outlet.

2. NEMA ConfigHow to Use Code Numbers to Determine NEMA Ratings

NEMA connector socket

Caption: NEMA connector socket

You’ll find a code on each NEMA connector.

Therefore, this code serves to identify device ratings.

The format is NEMA XY-ZP. Now, let’s check out what that means:

  • X – it indicates whether it’s a locking device. Therefore, straight blade plugs and receptacles with no lock won’t have a letter.
  • Y is a number from “2” to “23.” It shows the voltage, which varies from 115VAC to 347/600VAC.
  • Z – this is another number, but it marks the current rating. It can be from 15 to 60 Amps.
  • P – this stands for a plug. If you see an “R” instead, that indicates a socket or receptacle. 

A helpful customer service agent helps you identify and ensure a reliable connection.

3. NEMA ConfigWhat You Should Know About NEMA Configurations

Euro plug and NEMA plug on a white background

Caption: Euro plug and NEMA plug on a white background

You’ll find numerous NEMA configurations.

They feature combinations of contact blade widths. So, it’s vital to find a suitable one.

The main two types include non-locking and twist-locking connectors.

Therefore, check out the descriptions below and find optimal future configurations!

NEMA ConfigTypes of Non-Locking Connectors

A full vertical plug in power

Caption: A full vertical plug-in power

A non-locking connector features are folded and flat blades.

Therefore, it’s easy to remove a plug from the receptacle.

Here’s a selection of non-locking plugs based on the NEMA connector criteria.

NEMA Config–NEMA 1

This is among NEMA configurations that feature a two-prong design.

Product manufacturers use it for appliances like radios, clocks, and lamps.

So, these have a maximum of 125V. Today, you’ll only find 1-15R receptacles in older facilities.

Furthermore, the law requires grounded connections now.

Please note that polarized 1-15P, 1-20P, and 1-30P plugs can’t go into non-polarized slots.

So, your polarized 1-15P plugs should only go in matching sockets.

Interestingly, you can use “cheater plug adapters.” These allow a “3-prong” grounded 5-15 plug.

That means your 15 A 7-15 plugs could have three prongs.

NEMA Config–NEMA 2

This NEMA connector isn’t popular; only some manufacturers still use it.

So, you might find a standard for them, but please note the rating goes only up to 250V.

This is because the main application of 2-20 devices is to repair other units.

NEMA Config–NEMA 3 

Did you know NEMA 3 series devices still lack practical use?

So, the explanation is that future configurations will use these non-locking plugs.

Therefore, these electrical connectors have non-grounding, two-wire, and 277V features.

NEMA Config–NEMA 4

We don’t know much about these connectors since they also belong to future configurations.

However, these have a 600V rating.

Therefore, they have more than double the voltage of NEMA 4.

NEMA Config–NEMA 5

Grounding devices with three wires start with this option.

They have a 125V rating.

Apart from 1-15P plugs, there are 1-20 and 1-30. So their grounded options are 5-15, 5-20, and 5-30.

NEMA Config–NEMA 6

These NEMA configurations feature a similar structure to the previous category.

However, you place these in 250V constructions. Some combinations feature a “commercial” grade 5-15R and 5-20R receptacle for applications.

NEMA Config–NEMA 7 

You’ll find a 277V rating in these two-pole and ground connectors.

And some are with a neutral connection.

The hot pin features an enlarged line in the 7-20 variation.

NEMA Config–NEMA 8 

The 480V rating is characteristic of these three-wire, two-pole, grounding devices.

On the other hand, there’s no current use for this option.

It’s also for future configurations.

NEMA Config–NEMA 9

This option will become a choice in the future.

These are also three-wire, two-pole, grounding devices, but the difference is they have a 600V rating.


NEMA 10 used to be more popular with home appliances. However, a 14-50 device is a more common choice nowadays.

The configurations have a 125/250V rating.


You can use these on different AMP devices.

However, make sure to stick to NEMA regulations.

The maximum rating is 250V, which are three-pole, three-wire, non-grounding devices.


These share a similar configuration with the previous category.

However, the difference is they have a 480V rating.

On the other hand, the similarity is that they are also three-pole, three-wire, non-grounding devices.


The maximum voltage for the three-pole-three-wire, non-grounding devices is in this category.

The supported rating is 600V.

However, there are no current design examples for NEMA 13.


This category marks the start of four-wire grounding options.

You’ll find NEMA 14 in electrical appliances for clothes and cooking.

This is an improved version of the NEMA 10 series devices.

You can use a 14-50 plug even if you own a Tesla. 


These three-pole, four-wire, non-grounding devices don’t have current use.

However, you’ll find their voltage is up to 600V. Therefore, they’ll have broad potential.


These are 5-wire grounding NEMA configurations that don’t have a current use.

However, NEMA L21 has available applications.

Therefore, we can expect this series to become usable soon.


These are also 5-wire grounding NEMA configurations.

Although you can find a use for curved blades, the straight option still lacks applications. 


NEMA 23 has a similar construction to the previous two series. The difference is the support for 347/600Y equipment.


The abbreviation TT marks the Travel Trailer.

Therefore, this series is suitable for RVs.

You’ll find them in many parks across North America.

You can also find a grounded ML1 TT SS1 ML2 non-locking connector.

Furthermore, it could be an excellent choice for various applications.

NEMA ConfigTypes of Twist-Locking Connectors

A male hand puts plug in socket

Caption: A male hand puts a plug-in socket

The other main category covers twist-locking plugs.

Their history dates back to the 1930s.

The primary feature is that these have curved-blade, twist-locking connectors.

So, let’s check out the subcategories of these plugs! 


These are two-wire, non-grounding devices.

NEMA L1 features a single pole and a 125V rating.

Therefore, the amp devices supported have a 15A grade.


Unlike some other categories, this one doesn’t have a ground connection.

Furthermore, it’s a single-phase 250V series.


These go together because of their similarity.

They are 277 and 600 Volt two-pole, two-wire non-grounding devices.

Therefore, the difference is the voltage. You can even use FSL configurations in aircraft applications.


These connector families feature a 125V rating with ground locking.

They have two-pole and ground connectors.

You’ll often find NEMA L5 in the marinas.

The 50 A marine shore-power applications are common with this type.

Therefore, the boats can use that electricity.


NEMA L6 connector is another series of two-pole and ground connectors.

These have a 250V output but don’t feature a neutral connection.

The maximum is 20 Amp, which makes them suitable for IT products.

Therefore, you could find L6-20 connectors in backup and data systems.


These 2-pole and ground connectors serve as industrial and commercial illumination options.

In addition, the series is popular in lamps.


This electrical receptacle has a dedicated grounding connection.

It’s similar to the previous category but has a maximum rating of 480V.


This is the most powerful out of the two-pole families featuring a connector with the ground.

Therefore, the maximum rating is 480V.


These have three wires and two poles but no ground connection.

That doesn’t make them popular anymore.

However, you can still find some L10-30 devices in commercial applications.


This category features three-pole, three-wire, non-grounding devices.

Therefore, only several manufacturers make them.

The maximum rating is 250V, suitable for 30 Amp (L11-30) devices.


This wiring device is similar to the previous category.

So, these are three-wire, three-pole, non-grounding devices.

The difference is the voltage rating for the L12-30 devices.

So, NEMA L12 has 480V, which makes it suitable for many commercial applications.

That includes 30 Amp (L12-30) devices.


Some L(13-30) devices use this structure.

These are three-wire, three-pole, non-grounding devices.

However, it’s not often present in installations.

On the other hand, it has an impressive 500V rating.

That can be useful for L13-30 devices and applications.


NEMA L14 series devices feature three-pole and ground connectors.

So, these don’t have an impressive voltage rating.

Its limit is 125/250V, and you can easily find 14-30 connectors.

You’ll often notice them in audio systems and backup generators.


Three-phase circuits are the main application for NEMA L15 series devices.

Therefore, their rating is 250. They also come with three-pole and ground connectors.


L16 series devices are similar to the previous category.

They feature three-pole and ground connectors. As for the voltage, NEMA L16 has a 480V rating.


L17 series devices feature the highest-rated three-pole and ground connectors.

So, you use them in three-phase circuits with a voltage rating of 600V.

Furthermore, they are suitable for heavy-duty applications.


Although you use these for three-phase circuits, they lack grounding.

Therefore, these four-pole no-ground connectors don’t have many applications. Their rating is 120/208V.


Although you use these for three-phase circuits, they lack grounding.

Therefore, these four-pole no-ground connectors don’t have many applications. Their rating is 120/208V.


L20 series devices are similar to the previous category.

However, this larger diameter connector has a voltage rating of 347/600V.

Therefore, they are suitable for L20-30 applications.


The main characteristic is the 120/208V rating for these four-pole and ground connectors.

In addition, you’ll notice these twist-locking plugs in direct-current power applications for live events.


L22 series devices feature four-pole and ground connectors.

In addition, NEMA L22 is a larger locking connector with a voltage rating of 277/480V.


This series device has a blade with a tab with a neutral right angle.

In addition, the middle ground pin and 600V rating are also specific for NEMA L23.

Therefore, they are suitable for high-current applications.

Get Your Free Sample!

Enjoy a free sample worth UP TO $100!
Explore our custom services now. Email us at [email protected] for more details.

4. NEMA Config–Important Safety Characteristics

You might have 5-15R grounded receptacles.

However, the basic FSL configurations might not be enough.

Therefore, NEMA implemented additional safety features to the 5-20 and 5-15 configuration options.

Here are the extra requirements.

      4.1 NEMA Config–GFCI Receptacles

Inserting a mobile charger into a wall plug

Caption: Inserting a mobile charger into a wall plug

The abbreviations stand for ground fault circuit interrupter.

These are devices with the residual current.

They are a variation of the 5-20R receptacle.

The test and reset buttons are useful if a device trip occurs.

According to regulations, tamper-resistant GFCI receptacles are mandatory in outdoor locations.

Furthermore, you should apply them in wet environments.

That includes crawl spaces, kitchens, and bathrooms.

In addition, they offer a security service that can detect and prevent electrical contacts that could cause faulty circuits.

      4.2 NEMA Config–Resistance to Tampering

Tamper-resistant receptacles are a safety feature from about a decade ago.

It’s a child-proof measure.

If a kid tries to insert something into the NEMA 5-15P plug, this will prevent live electrical contacts.

The downside of tamper-resistant receptacles is inserting two devices at once.

Therefore, the application isn’t completely safe for 5-20P plug and other configurations.

If you are protecting a cable assembly, consider using a shielded cable.

     4.3 NEMA Config–AFCI Receptacles

Electrical 2 prong plugs next to a NEMA 5-15 grounded power, and AFCI Outlet

Caption: Electrical 2 prong plugs next to a NEMA 5-15 grounded power and AFCI Outlet

AFCI is short for arc-fault circuit interrupter.

If you have grounded 5-15P plugs, you can use these as a replacement for standard circuit breakers.

So, you apply these in an arcing environment that could be dangerous.

The regulations specify you should have AFCI in living rooms, family rooms, libraries, and similar areas.

So, make sure to include them with your 5-15P and 5-20P plugs.

     4.4 Protection Against Surges

A random surge can damage your devices.

That’s why using a protection device for a 2-15 or 5-15 plug is smart.

So, you can find these for 120V electronic devices like computers and TVs.

Check the manufacturer’s instructions to discover how to use these devices.

     4.5 Weather Resistance

These are protective receptacles like 5-15R or 5-20R receptacles.

These provide a service for protection from bad weather. The materials used offer impressive insulation and UV resistance.

You’ll often find double-insulated devices.

Apart from tamper-resistant receptacles, WR units are a wise move in the backyard if you have children.

     4.6 Detecting Leak-Currents and Interruptions

These are special cord sets with an LCDI abbreviation.

The statistics indicate that damaged cords cause 350 deaths yearly. Therefore, it’s vital to use a protection device.

That can prevent live electrical contacts. The common manufacturer LCDI construction involves circuitry that discovers potential leaks.

5. The Role of Color Coding Your NEMA Device

Color rolls for custom color coding

Caption: Color rolls for custom color coding

NEMA doesn’t have any specific requirements for colors.

So, installing three-wire grounding devices or going for a different setup is irrelevant.

You are free to choose colors for your 5-15P and 5-20P plugs.

The advantage of color-coding is that you can navigate through basic NEMA 5-15R and 5-20R configurations easily.

You’ll also notice industries using coloring on L11-30 devices and similar units.

The common colors found on a single or duplex configuration include:

  • Green. These are suitable for demanding use. That’s why you’ll often find a connected device to these units in industrial applications. 
  • Blue receptacle. This could imply surge suppressors as part of the construction.
  • Yellow. That could indicate the three-wire-three-pole, non-grounding devices used are corrosion-resistant.
  • Orange triangle. If this arrives at your current shipping address, there is an isolated ground. So, this is also a requirement in some locations.
  • Red. This shows product manufacturers secured an outlet with a special service. For example, they could serve as an alternative source in hospitals. 

6. NEMA Config–An Overview of the Break-Away Tabs

Grab a duplex 1-20R and 1-30 receptacles or similar construction.

You’ll notice metal tabs in the upper and lower parts.

If necessary, this allows wiring on separate circuits.

Therefore, this increases the versatility of duplex receptacles.

You can even install a neutral wire to share between these units.

Check the manufacturer’s instructions to discover the detailed steps to do this.

7. NEMA Config–Are There Any Other Standards?

Each NEMA connector has configuration and dimension requirements.

You can find them in official standardization documents used as a security service for protection.

The purpose is for the manufacturers to secure that each NEMA connector meets other relevant regulations.

For example, your NEMA 5-15P plug must comply with the Federal Specifications, Defense Logistics Agency, and the National Electrical Code.

These could refer to protective receptacles, tamper-resistant receptacles, and other safety features.


We hope our guide helped to find a suitable NEMA connector for the desired application.

If you have any questions, don’t hesitate to contact our helpful customer service agent.

Our team has years of experience and is ready to assist with the selection process!

Get Your Free Sample!

Enjoy a free sample worth UP TO $100!
Explore our custom services now. Email us at [email protected] for more details.

Hey, I am John, General manager of Cloom and OurPCB.

I am a responsible, intelligent and experienced business professional with an extensive background in the electronics industry.

Reach me at [email protected] to get a quote for your projects.


Fill in your details and we’ll get back to you in 24 Hours.

contact us


Fill in your details and we’ll get back to you in 24 Hours.