Choosing Waterproof Connectors

It is hard to believe how connectors are treated by trained professionals. During my 30 years in this industry, I have seen a connector fitted to a sea buoy that was so encrusted by salt and grime that it could not be unplugged. I have seen connectors dropped onto concrete floors, dragged across muddy fields, and thrown across film sets. I have even once seen a scientist use a connector as a convenient handhold to climb onto a large machine.

Connectors must perform in the toughest conditions

These are extreme cases, but it is a huge testament to connector designers and manufacturers that connectors can withstand this kind of treatment. Most normal applications do not require connectors to function under these conditions.

However, many customers will need connectors to be installed in tough environments. Anything from domestic security cameras to power supplies for outside broadcasts will need connectors that will stay sealed in wind, rain and sun.

For some customers, the only reasonable choices are connectors with industrial or even military heritage. Military specification circular connectors such as those available from Amphenol (045-0146) perform under some of the toughest environments on earth. With metal body shells and high-reliability contacts, they are designed to provide secure connections for mission-critical equipment.

There is a penalty to be paid for selecting military-style connectors. To provide the necessary robustness, military circulars tend to be bulky and their performance requires them to be manufactured from the highest-quality materials. While some applications can use more modest designs, the pedigree of military connectors gives customers confidence in their performance.

The industrial world has plenty of options for waterproof connectors. Some share a common heritage with military connectors, like the Trim Trio family from Souriau (848-8105) . However, for customers who require a more slimline alternative, manufacturers like LEMO provide high-performance connectors for professional applications. The T series (144-2717) is waterproof, shielded and boast contacts that deliver more than 3000 mating cycles.

Understand the Environment

Before specifying a waterproof connector – or any component – the first step is to understand the environment in which it is needed to function. The term “waterproof” means many things to many engineers. Some products may simply need to resist the occasional rain shower, whilst others must withstand the pounding of waves on the deck of a ship.

Therefore, just as it is necessary to ensure a product is suitable for the level of protection required, it is also important not to over-specify the connector required. Fortunately, there are many cost-effective connectors available that can perform to a certain standard.

IP ratings, courtesy of Amphenol RF

The system of IP ratings makes it easy to choose the right connector for your environment, but it is important to remember that there are other ways to classify connector performance.

Know the Limitations

The other key characteristic that will affect the standard of the connector is how frequently the connector will be used. One of the key characteristics of a connector is its mating cycles, which is the measure of how many times that connector can be mated and unmated. There are several aspects that govern how durable a connector is, from contact design to the materials chosen. However, in general, connectors with higher ratings bring with them higher price tags.

Often, waterproof connectors are designed to high specifications, but not all applications for harsh environments need the high reliability that military connectors deliver. For those customers, there are plenty of options available.

Circular Connectors

The industrial environment brings with it some harsh conditions. Vibration, high temperatures and aggressive chemicals can all be found on the factory floor, and there are plenty of connector solutions that are designed to perform under these conditions. The M12 connector has become popular for factory applications including automation, control and robotics. It is slim and lightweight, and many manufacturers provide M12 connectors that are sealed to IP67 and greater. One example, available from HARTING (123-1054) , is sealed to IP67 and is suitable for a wide range of factory-floor applications.

For customers who need a higher power rating, the Buccaneer series from Bulgin provides a well-proven and popular option. The Buccaneer (426-0953) is sealed to IP69K, and is manufactured from polyamide to resist both water and the effects of UV radiation, making it an ideal solution for outdoor installations.

Connectors for Cars

While many circular connectors offer protection against the environment, they are not suitable for all situations. Designers can also take advantage of products that are intended for automotive applications. Connectors that are designed for use on cars and trucks have several characteristics that make them ideal for the industrial user. They are designed to withstand all the conditions that the car experiences, from water and mud to vibration and extreme temperatures. At the same time, they are designed to be manufactured in high quantities, be easy to terminate and be readily available. All of these characteristics make them an attractive solution for customers who require a fit-and-forget waterproof connector.

Automotive Connectors - Ideal for Industry

Products like the DT series from Deutsch (042-5692) and the MX150 series from Molex (720-5726) are designed for use in cars, but they also provide cost-effective alternatives for industrial designers who are looking for reliability in harsh conditions. And as the industrial environment becomes more connected, waterproof versions are now available of the data connectors that are common in modern communications, including the latest USB-C types (124-5632) .

Choose your Connector Wisely

Adopting a waterproof connector need not be an expensive process. For every high-performance, high-reliability (and high cost) option, there is a much more reasonable connector that still provides protection against the elements.

Take the time to understand the requirements of your application and do your research. Waterproof connectors need not be as expensive as you think.