ELECTRICAL & ELECTRONICS TEMPERATURE CONNECTORS
PEI-GENESIS
How picking the right connector first time can make the difference
When designing industrial equipment , the operating temperature of the product is often at the top of the list for design engineers . This makes sense , after all , you don ’ t want to keep replacing failed equipment . However , while engineers give a lot of thought to heat in the equipment itself , the performance of the connectors and cables that join different devices is often overlooked . Here , Jonathan Parry , Senior Vice President of Global Operations and European Managing Director at cables and connectors specialist PEI-Genesis , explains how to choose an extreme temperature connector .
For the average member of the public , choosing a connector is often as simple as deciding between a one or two metre USB cable , and we still get very annoyed when the connection starts to become unreliable .
For the engineer the choice is far more complex , and the consequences far more serious than having to wiggle the connector until it works . A dropped connection could mean losing control of heavy autonomous equipment , a stopped machine and jammed-up production line , or many other detrimental effects that are best avoided .
While the working equipment in industrial settings is often well monitored by governing software and vigilant engineers , it ’ s often the case that the connectors are overlooked , despite them being just as crucial as any piece of line equipment .
HOT STUFF Heat , particularly in the extreme , is a factor that engineers constantly tackle .
Heat is a natural consequence of many industrial processes , and many more still involve heat directly in the process , such as smelting and other metalworks .
Most equipment uses active cooling to control this heat , such as ventilating fans , cooling lubricant sprays and water-cooling . For the connectors this is often not possible , which makes the choice of connector in the first instance very important .
When dealing with hot environments it ’ s tempting to simply pick a connector with a metallic housing , such as steel or aluminium , because these metals typically don ’ t melt before a few-hundred degrees Celsius . Doing this overlooks major problems , however . For instance , the connector enclosure might easily withstand the high temperatures in question , but inside the enclosure can act as a heatsink because heat isn ’ t actively wicked away .
Many connectors , such as common USB and serial ports , rely on plastic inserts to house the contacts , while other connectors may also enclose electronic components such as resistors , ballasts and rectifying circuits , which may be susceptible to temperatures lower than the enclosure material .
Even if temperatures don ’ t actually melt or scorch these plastic components , procedural stress caused by the high temperatures , as well as the effects of thermal expansion and contraction can cause connectors to fail well before their expected lifecycle .
Particular attention must be paid to connectors in hot and enclosed environments , such as on trains and boat engine rooms , where low-smoke-zerohalogen ( LSZH ) plastics are often used to avoid the build-up of dangerous fumes or explosive atmospheres created by burning or outgassing plastics .
An example of this style of connector is the PEI-Genesis supplied VEAM CIR from ITT , which has been specifically designed for extreme temperatures . This connector uses specialised LSZH plastic inserts and a variety of enclosure materials , which gives it the capability to meet ISO 834-1 fire standards , where the connectors are exposed to temperatures as high as 800 degrees Celsius .
LEAVING CONNECTORS OUT IN THE COLD Sliding back down the scale , we reach the arena of cold-temperature connectors . This initially seems far easier to solve than heat , primarily because most industrial processes are exothermic .
Therefore , the cold temperatures that connectors are exposed to are often natural , with connectors being continually exposed to the elements . These cold environments often preclude the use of many plastic and rubber enclosed connectors because they can freeze and crack , creating openings for moisture to wreak havoc . Metal is also a tricky proposition , as it ’ s often prohibitively complex to design a metal enclosure with tolerances tight enough to protect from the weather .
With the correct choice of connector configuration and materials , however , this style is perfectly possible . The PEI-Genesis supplied Sure-Seal Connectors range is one such low-temperature capable connector . Boasting IP67 and DIN 400 50 ratings , these connectors are enclosed in a PVC nitrile plastic which remains flexible , supple and resistant to cracking down to temperatures as low as -40 degrees Celsius .
Many industries treat connectors as a quick , one-time decision taken during integration , despite the consequences of failure perpetually bringing the problem back onto the agenda . With some more consideration , though , it ’ s possible for that decision to be truly long-lasting .
For further information , please visit www . peigenesis . com
60 PECM Issue 47