What Is IEC 60309 and How Is It Used?

pin and sleeve mating pair

It’s almost impossible to be in the industrial electrical market without coming across a reference to IEC 60309. Sure, you could just read the Wikipedia page, but even our team here at Amp Authority gets dizzy trying to make sense out of it by the end. Our objective is to leave you with a clear and concise understanding of this IEC electrical standard, its practical applications, and some common examples of products that follow it.

The Short Definition of IEC 60309

First things first: if you just asked “Wait, what is the IEC?” then you need to read this. For those who know, you are already aware that all IEC standards range from 60000–79999. Specifically, IEC 60309 deals with “plugs, socket-outlets and couplers for industrial purposes”. One thing that sometimes people is that the IEC 60309 standard does not have to be used in an industrial setting. We’ve seen IEC 60309 pin and sleeve devices in commercial settings and even residential (albeit rarely).

We subscribe to the “KISS” (keep it simple, stupid) principle here. Therefore, we feel no shame in saying that the IEC 60309 standard is nothing more than making sure that the right plugs go into the right holes. More specifically, IEC 60309 is meant to deal with light to heavy duty industrial grade applications at high voltages and currents (amperages). The maximum allowable voltage is 690V and the highest current is 125A.

Mating and How It Works

Here’s where it starts to get a little tricky. We mentioned it earlier, but the concept to IEC 60309 is that plugs mate safely without arching or malfunctioning. The method derived from the standard is what is known as the “Pin & Sleeve” concept. This basically means that there are a certain number of pins on the male plugs/inlet and a corresponding connector/receptacle on the female that matches. Under this concept, you should never be able to mate the wrong male and female pieces. Additionally, when mated, the pair should be resistant to water. In Europe, the standard is that a mated pair is IP 44 rated which means it is splashproof. Roughly 90% of pin and sleeve devices fit this description.

The mating system can definitely be confusing, even for those in the electrical industry. We are going to provide the simplest explanation possible as to how to ensure you have a pair that will mate:


We found a good description of how these pin and sleeve devices are named in the market from Mennekes:

pin and sleeve naming convention

As you can see, its fairly straightforward to determine what kind of Wiring Device you would need. The only tricky thing is the “7” above. We will break this down in the next few sections.

Color Coding

You cannot mate a pair that aren’t the same color. Red goes with red, blue goes with blue, and so on. The reason this is the case is due to voltage compatibility. IEC 60309-2 (which we will explain later) makes sure that the pin and sleeve configurations are such that different colored plugs and connectors should never be able to mate.  However, you need to make sure that they have the same number of poles and wires. We will explain this below


As mentioned, you have to mate plugs that are the same color. However, you also have to mate plugs that have the same number of poles (number of energized pins) and wires (the number of poles plus ground) as the receptacle or connector. Thus, the standard dictates that a clock is used such as the one below for North America:

IEC 60309 mating close

What’s critical to understanding the clock is that it specifies the female position of the ground pin. So, if we have a manufacturer that has a part number called a 320P7W, that means the ground pin (the largest pin) of the plug is at the 7 o’ clock position above, right? Not so fast! It means that the connector, not the plug, is in the 7 o’clock position. To get technical, that would make the plug ground pin in the 1 o’clock position but don’t worry about that part. Just take away that the female determines the clock time.


We will dive deeper into this in a later post, but you need to know which type of power is being supplied. With the IEC 60309 standard, we are overwhelmingly dealing with AC (alternating current) power over DC (direct current). We are also mostly dealing in 3 phase power over single phase power. Something that trips a lot of people up is whether 3 wire devices can be three phase power. The answer is no and the reason why is quite simple; there aren’t enough pins. You need at least 3 pins, or poles, carrying current to qualify as 3 phase power.

Those four small paragraphs should tell you everything you truly need to know to understand how these types of devices safely mate together. There are, of course, nuances and exceptions here and there but that’s beyond the scope of this article.

Wait, There Are Actually Two IEC 60309 Standards?

We mentioned above that there is an IECE 60309-2 standard. Does that mean there’s a 60309-1? In fact, it does. 60309-1 deals with general functional safety requirements (environmental ratings, material specifications, etc.). IEC 60309-2 specifies what we refer to what we just covered above, that all units with the same voltage and amperage must be properly mated only with the appropriate pairing unit. In the industry, you may hear this referred to as products being “intermatable and interchangable” and this is important to grasp not only from a safety standpoint but also from the manufacturer side. This means that you can buy a Hubbell 320P7W and mate it with a Mennekes 320C7W. There are actually 5 sub-standards but we will stop now for the sake of relevancy.


European Standard

IEC 60309 is the true standard in Europe. As mentioned earlier, about 90% of the devices in the market are splashproof, or IP 44. The most common amperages in the EU are 16, 32, 63 or 125. Additionally, the most common voltages are yellow, blue and red devices between 100-480V. Lastly, it is common in the EU that there’s an extra pin called a “pilot pin” for 63A and above. This smaller pin is designed to ‘make’ after all the other pins when connecting, and to ‘break’ first when disconnecting. It is used to switch off the load which can help prevent arcing which may cause damage to both the equipment as well as the operator.

IEC 60309 in the US

While NEMA devices are definitely the market standard, IEC 60309 is still quite prevalent in the United States. However, there are some differences in their practical application than the European market. First, while almost 90% of EU devices are IP 44, the exact opposite is true in the US. Approximately 90% of the devices are IP 67 which is waterproof. It’s tough to know exactly why, but the US industrial market has adopted a stricter standard on watertightness. Nonetheless, the effect on the physical devices changes to incorporate a “locking ring” on the male device that provides extra protection against liquids.

In addition, the “pilot pin” mentioned earlier tends to not exist on Wiring Devices in the US. The amperage and corresponding voltage standards are also different. For example, the US amperages used in industrial are 20, 30, 60, and 100A and the most common voltages are 120, 250, and 480. In parts of Canada, 600V is common.


The last point worth knowing would be the types of companies that manufacture these products. Here is a non-comprehensive list of the largest Pin & Sleeve producers in the world:

Wrapping It Up

At this point, you should feel confident about the standard, what it means, and why it matters. We hope this gives you a glance at the IEC electrical market. Let us know what we missed and thanks for reading!