Here Amy Wells poses the questions you need to be asking when specifying a connector
Connectors come in all shapes and sizes depending on environment and application. There are literally thousands of options, sometimes for the same job. Inevitably, this can cause a lot of confusion. To make sure you find the best product for every job, there are a few questions you might want to ask yourself before making a purchase.
First things first, size matters. Do you know the physical size of the connector you need, or are you limited in space and height by the job? Hundreds of connectors are used in wire looms; perhaps even thousands if these are part of an automated manufacturing line. In each case, the requisite space needs to be analysed and the correct connector specifications chosen. Sounds simple, but you'd be surprised how often people come a cropper.
The next question you need to be asking yourself is how many poles the connector needs.
Different applications require connectors with different poles. Future-proofing your choice can be a good idea, especially for a new product. So it's worth considering whether you should go for more poles than originally required.
Do you know how many mating cycles the connector needs be able to make? Despite what you might think, mating cycles refer to the number of connection or disconnection operations the connector can withstand, while still meeting the specifications for maximum resistance and pull force. Every connector has an expected number of cycles before efficiency is compromised and the connector needs replacing.
This brings us nicely onto the proper protection. Connectors may be susceptible to ingress of foreign materials, such as moisture or dust. Connector protection is provided by the housing and the seal. The IP standard rating system defines the degree of protection provided. The first digit defines the protection against the ingress of dust particles; the second digit defines the protection against the ingress of water. Choosing the right connector for the job is key.
One of the most important factors is knowing what applications and environment a connector will be operating in – we can’t stress that enough. Electromagnetic radiation can interfere with electrical equipment. In applications where electromagnetic radiation is likely to be higher than usual or where operations are critical, connectors need to have electromagnetic fields (EMF) shielding.
Similarly, connectors used in explosive environments must be ATEX certified and components used in military applications need to have Mil-Spec to ensure the highest levels of performance.
Furthermore, connectors in particularly harsh environments - like those in the oil and gas industry - need to be up for the job at hand. Knowing the minimum and maximum operating temperature is essential for specifying a rugged connector that meets the temperature range set by the application.
It’s not just the connector’s specs you have to be aware of when planning a job. Lead times from manufacturer to supplier can be lengthy, running from anywhere between four to sixteen weeks. It's no good specifying a part that has a typical 16 week lead time if it will hold up the production process. To combat this potential issue, a good distributor will always hold a substantial amount of stock on the shelf.
Speaking of distributors, they will also be able to advise you on cost effectiveness. When crafting wire looms, connectors are ordered in bulk, with the resultant savings passed on to the customer. However, if you need just one connector - perhaps if it's a specialist part - you won't be quite as lucky. A good working relationship with an experienced distributor can result in alternatives being sourced for a fraction of the price.
Finally, as any lifestyle magazine will tell you, compatibility is paramount. If you're retrofitting new connectors to old or simply mating two together in a loom, they need to be intermateable. If not, you risk damage to the system and or data/power loss.
Amy Wells is business development manager at Electroustic, Milton Keynes, UK.