Mueller Electric Blog

M12 Connections Explained: What Are They & Which Are Best For Your Purpose?

Posted by Deanna Craver on Apr 5, 2022 1:20:03 PM



M12 CONNECTIONS EXPLAINED:
WHAT ARE THEY AND WHICH ARE BEST FOR YOUR PURPOSE? 

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With so many various types of
M12 connections and options to choose from, such as pin count, pin positions, connection coding and IP ratings, the selection process can seem rather overwhelming. What does it all mean and how do you know which connections are right for your specific application? This article will explain these terms, what all of them mean as well as all of their classifications, so that you can discover which M12 connections are right for you. 


M12 CONNECTIONS … WHAT ARE THEY?

The name M12 came about pretty simply: M stands for the unit of measurement taken (in this case, metric) and 12 stands for the length of the diameter taken across the outside of the threads (12mm). M12s have circular connections and, because of their circular shape, they possess high current capabilities and are much easier in obtaining ingress protection (IP) ratings, or ratings that tell how well connections are able to keep out elements such as dirt, sand and water, than their rectangular counterparts. This makes them an excellent choice for use in factory automation applications, or in any tough or harsh environment where dirt or dampness is involved. 


PIN COUNT

Choosing the right M12 connections depends on your specific application. M12 connections come in a variety of pin positions, anywhere from 2, 3, 4, 5, 6, 8, 12 and 17 pins. The number of pins varies depending on the signal type and number of signals, connection coupling and code.
 

Pin counts differ according to code. Connections with B code, which are used for Profibus connections, typically have 5 pins, although their pin count can vary from having 3-5 pins. Connections with C code, which are used for AC power applications, usually have 6 pins, although their pin count can also vary from 3-6 pins. Connections with D code, which are used for Ethernet applications involving data transfer of up to 100 Mbits, always have 8 pins. Connections with A code, on the other hand, are used as all-purpose connections in such a wide variety of factory automation applications, such as attaching to sensors, actuators and a number of other smart devices, that the pin count can be anywhere from 2-17 pins. 


PIN POSITIONS AND CONNECTION CODING

Different pin positions have been created to coincide with the different types of coding that have been devel- oped according to function. This way the pin positions act as a fail-safe and eliminate any mistakes of cables being connected that were made for different coding. For instance, you would certainly connect cables that both have A-coding and are being used to hook up sensors with corresponding equipment, however; you would not want to connect an AC power cable to an Ethernet cable. 

Present coding

 

CODING FOR DATA APPLICATIONS

Below is a description of the different coding classifications currently used in factory automation and what they mean.

A-CODING
A-coding (also known as Micro-DC) for factory automation cables is the most widely used coding in factory automation applications of all the types. These connections are used in data applications primarily involving DC power. A-coding is used for attaching actuators, attenuators, sensors, motor-operated switches and other devices to automation equipment. A-coded connections are also used to transfer up to 1-Gbit of data in Ethernet applications and can have anywhere from 2 to 17 pin positions.

B-CODING
B-coding is unique in that it contains a reversed single keyway, which allows 2 unique M12 connections to be mounted on the same panel without the risk of incorrectly coupling connections to equipment with varying voltage and amperage. B-coding for factory automation cables is used in fieldbus connections involving Profibus and Interbus. B-coding connectors typically have anywhere from 3 to 5 pins.

C-CODING
C-coding (also known as Micro-AC) is strictly used in cases where AC current is involved, such as with AC actuators, sensors and other AC devices. Because of this C-coding is not as commonly used as the other coding types. Connections with C-coding all have extended grounding pins and double keyways for added safety to prevent them from being mistaken for other similar-looking connections or being coupled with the wrong cables. C-coding connections have anywhere from 3 to 6 pins.

D-CODING
D-coding is specifically used in network cables for industrial Ethernet applications to transfer data up to 100-Mbits. The insides of cables with this type of coding consist of either 4 wire connectors (D-coding) with 2 pairs of Cat 5e cables or else M12 8 wire (A-coding) connectors with 4 pairs of Cat 5e cable. D-coding can also be used with Profinet, Ethernet/IP and EtherCat systems. D-coded connections usually have 3 to 5 pins.

X-CODING
X-coding has been introduced in the recent years and is quickly becoming a standard for use with high-speed industrial Ethernet applications. X-coding has capabilities of transferring large amounts of data at high speeds, up to 10-Gbits of data. X-coding is expected to eventually replace A- and D-coded parts for Ethernet applications. X-coding applications include high-speed industrial Ethernet and Cat6A. X-coded connections always have 8 pins. 

 

Soon-to-be coding

 
CONNECTION CODING FOR POWER APPLICATIONS
While A, B, C, D and X connection coding make up the majority of factory automation cable use today, new coding is being introduced as well. K, L, S and T coding are all used for power applications. Rapid advancements in Industry 4.0 technology have resulted in these codings providing improved performance in specific power operations. S- and K-coding are both used for AC power applications and it is believed that S-coding will at some point take the place of C-coding that is currently used. T- and L-coding are both used for DC power applications and it is believed that T-coding will at some point take the place of A-coding that is currently used. P-coding has also been developed for various uses where quick connects and disconnects of cables are needed.


IP RATINGS
As mentioned earlier, the circular shape of M12 connectors makes it easy to assign them IP ratings which classify how well connectors are able to block out unwanted elements that can cause corrosion and other problems. Because of the rugged design of M12 connections, they are an ideal choice for use in factory automation.

The International Electrotechnical Commission (IEC) came up with these rating classifications and international standards which set the bar for what connections can withstand. There are three common IP standards associated with M12 connections which are IP67, IP68 and IP69.

What are the differences?
The first digit (in this case, the number 6 in all three ratings given) refers to the connection’s resistance to solid objects, such as dirt, sand or dust. The significance of the number 6 means that after being in contact with solids for 8 hours, the connection does not absorb any “harmful” dirt and it is still functional. The second digit refers to the connection’s resistance to water. In the examples given we have 7, 8 and 9.

The significance of the number 7 means that the connection can be submerged in a greater depth of up to a 1 meter of fresh water for half an hour and still be water resistant. The significance of the number 8 means that the connection can be submerged in up to 1.5 meters of water for a half an hour and still be resistant. The significance of the number 9 means that the connection can actually withstand high pressures, high-pressure jet sprays, wash downs and steam cleaning procedures.


MAKING YOUR SELECTION
Now that you know about pin counts, pin positions, coding and ratings, you are ready to select your connections. Mueller Electric can help you with the process. Mueller Electric’s M12 factory automation connections have the most reliable and efficient connection standards for industrial machinery and industrial automation applications. Having high-performance capabilities, small footprints and extremely low failure rates, Mueller Electric’s connections are ideal for use in the toughest conditions.


            Mueller Electric offers M12 cable connections with features such as:

Industry-standard screw-locking mechanisms
IEC ratings of IP67, IP68 & IP69
A, B, C, D & X-coding options
Field-installing cable and panel-mount options
Moulded straight and right-angle variants
Pin ranges of 2, 3, 4, 5, 6, 8, 12 & 17 positions
Shielded PVC and PUR options for cables


What’s more, if your automation takes place in a moist environment or if your equipment requires washdowns, factory automation cables with a minimum IP rating of IEC-IP68 are recommended. These cables provide a strong, secure and sealed connection between your automation equipment and robots, sensors, actuators, machine vision systems, motor-operated switches and other smart components, even in humid or moist conditions. The IEC-IP68 rating is highly recommended for factory automation in both the food and beverage and measurement and control industries. The IEC-IP69 rating is what is most often used in road vehicle applications. All of Mueller Electric’s M12 connections have an IEC ratings of IP67, IP68 and even IP69, the highest IEC rating available.


CONTACT MUELLER ELECTRIC
Still have questions about M12 connections? Give Mueller Electric a call at 800.955.2629 or contact us here. One of our knowledgeable staff members will be happy to help you select the connections that are best for you. With a wide array of factory automation connections, including a large selection of UL-listed connections in our factory automation catalog, Mueller is sure to have something for everyone. If by chance you do not see what you are looking for, Mueller also specializes in creating custom-made cable orders and can put together a solution just for you and your unique application needs!

Fore more information on M12 connections, feel free to visit Mueller Electric at www.muellerelectric.com.


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Topics: electronics, engineering, Instrumentation, Factory Automation Cables, Factory Automation, Connectors

How to Select the Right Electrical Clip

Posted by Mona Weiss on Apr 11, 2018 8:23:21 AM

From electrical design to maintenance, engineers must determine what electrical clips (also called alligator or crocodile clips) are best suited for their project.

These clips can range from small to large, be made of a wide range of materials, come in various jaw types, handle wide ranges of electrical current and can be certified for safety by being UL-listed.

With such a wide range of options, there are many factors to come into play when selecting clips


Amperage

Typically, electrical and electronic clips are rated by their ability to handle varying levels of current which is measured in amps so you will need to know the amount of current that you will be dealing with.

Once you know the level of current, you can calculate the amperage rating required for the clip.

The formula for Amps is Watts divided by Volts.

The amperage capacity of a clip is typically listed right on the clip itself.

Generally speaking, larger clips are able to handle more current, however, that doesn’t always mean a larger clip is always necessary. Solid copper clips are able to handle higher levels of current and carry a higher amperage rating than its zinc plated steel counterpart. For example, a heavy duty clip for battery and test work applications may be rated at 50 AMPS for the zinc-plated steel version while the same sized clip made in solid copper is rated at 100 AMPS. 

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Another factor to be considered is how the clip needs to connect to its point of contact. Clips come in all shapes and sizes with different types of jaws and teeth. Clip jaws can come flat nosed, with teeth, or wrap around a terminal or pipe. Some clips have flat wide noses with teeth and others may be rounded to grab round objects. Deciding which clip to use is dependent of what the clip is grabbing on to and will vary per application.

Flat nosed clips are typically used in paint grounding.

Smaller clips with teeth are used for test and measurement.

Larger clips that wrap around will provide a strong grip and may penetrate a layer of paint. These are often used for battery charging and grounding.

Flat wide jaws with teeth are perfect for grounding and work holding uses.

There are, however, a tremendous number of applications for all types of jaw styles. As technology progresses, so do clips, with new types being invented all the time.

For more on different types of clips and what they are used for, check out our guide to clips

Clamp Pressure

Clip grabbing strength, or clamp pressure, is another factor to take into consideration when selecting the right clip. Clamp pressure usually increases as clip and spring size increase. Larger clips will have a stronger grip than smaller clips. In some cases clips can be made to have less clamp pressure which can be helpful for delicate or detailed situations.

Clip Size

There are many different sizes of clips and size can sometimes be important to consider. One determining factor is if there is a space requirement. Another factor is the amount of clamp pressure required, as well as the amperage rating needed.

Some clip sizes are determined by the application itself as there may be limited space where the clip can fit.  Naturally if you have a small space then you probably will pick a smaller clip.

Higher amp rated clips tend to lend themselves to uses where a tight space is not a concern. The environment may dictate what a clip size may need to be as the larger clips tend to hold up better in harsh environments such as electroplating.

There is no real guideline on determining what clip size to use. Some engineers try to make sure they have the right amperage rating, clamp pressure and jaw type in the smallest package possible to reduce the possibility of “overkill” and inflating costs unnecessarily. Other engineers go one step up in size to ensure all bases are covered. In most cases, several different sizes of clips are used in various prototypes to test first hand which clip size is best.

Material

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Clips are made with zinc or nickel plated steel, stainless steel, solid copper, gold plating and even nickel-silver.

Generally speaking, zinc or nickel plated steel is the most cost effective material used in clips.

Solid copper clips can handle higher levels of current better than similarly sized clips made of other materials.

The environment where the clip will be used can determine what material should be used for a clip. For example, stainless steel clips can withstand marine, caustic or corrosive environment better than other materials. Other clips that can be used in marine environments are marine rated clips which are made of solid copper for greater connectivity but with moisture resistant springs which significantly extend the life of a clip used in the vicinity of water and salt.

We did an experiment to show how marine and stainless steel clips hold up compared to other clips. Read about it here. 

Read about different metal finishes for clips here.  

Safety

Safety is always a consideration when working with electrical components, but some more than others.

For instance, when using clips and cables for grounding and bonding, an exposed clip works just fine, while other applications it may call for an insulated clip.

UL Listed products are certified for safety. UL Listed clips and connectors are certified to insure that human hands cannot come in contact with the conductors while in use and energized.

Other applications may call for clips to be utilized in a “hands free” environment which means that the clips are not manipulated or touched while a circuit is energized. The clips still need protection from touching each other or other parts which could interfere with the electrical signal or cause a short, so insulators or “boots” are placed over the clips to protect them.

For help in selecting clips with different features, try our clip selector.

Topics: Test & Measurement, Static Electricity Grounding, Grounding, electronics, crocodile clip, engineering, alligator clip, Marine Clips

PVC vs Silicone vs Rubber Wire Insulation

Posted by Mona Weiss on Feb 2, 2018 10:45:14 AM

There are many varieties of wire and cable insulation suited to a variety of needs.  Insulation is made of a non-conductive material that surrounds the wire and will resist an electric current.  Keep in mind that The thickness of the insulation determines the voltage rating. You can get high voltage from any kind of insulation depending on the thickness.

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PVC is the most common type of insulation and the least expensive and has a wide ranges of uses. It’s very resistant to chemicals, corrosion, impact, abrasion, and weathering. The temperature range is -40°F to 221°F.  The wire is generally hard to the touch and doesn’t provide as much flexibility as other types of wire.

Silicone is highly flexible and heat resistant and is preferable to use for extreme temperature environments from -103°F to 482°F. It is soft to the touch. A downside of silicone is that it is generally more expensive and also attracts static so it has a tendency to get dirtier than other wires, as the dirt is attracted to the outside of the wire.

Natural rubber can be thought of as a cross between silicone and PVC in terms of some of its advantages and disadvantages. It has better abrasion resistance than silicone but not always as chemically resistant as PVC. It’s better suited to outdoor and industrial environments. Its temperature range is -13°F to 140°F which is less than the other two kinds of insulation.  

Topics: electronics, wires

How to Properly Crimp an Alligator Clip Onto A Wire

Posted by Mona Weiss on Dec 7, 2017 1:35:26 PM

 Many people don't know the right way to properly crimp an alligator (or crocodile) clip onto a wire. This blog post (and video) shows how to do it step-by-step.

  

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Step 1: Strip the wire to about 3/8"

 

 

 

 

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Step 2: Bend the stripped wire end over the outer jacket

 

 

 

 

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Step 3: Insert the wire inside the jacket

 

 

 

 

 

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Step 4: Crimp

 

 

 

 

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It's important to fold the wire over the insulation before inserting and crimping because it prevents the wire from being pulled off. 

 

 

 

 

 

 

To browse our alligator clips,click here to see our digital catalog and see where to buy, or click here for our clip selector to narrow your search.  

To learn more about different types of clips, check out our clip guide.

 

Topics: crimping, electronics, crocodile clip, engineering, alligator clip, crimp