Making the choice between circular and rectangular connectors for the energy industry.
Presented by HARTING, Inc. of North America
Will Stewart, Industry Segment Manager, Energy
Sometimes tradition, rather than functionality, dictates the type of connectors designers specify for an application. That’s the case with circular connectors in the energy industry. Despite their historical employment in this market, the fact is, rectangular connectors can be a better choice in many situations. Here’s why.
Q: What types of industrial-rated connectors can engineers choose from today?
A: Design engineers have two choices for industrial electrical connectors: circular and rectangular. Circular connectors have a long history in military applications, food and beverage processing, and the energy industry. Rectangular connectors are used widely in modular machine design, factory automation, robotics, transportation, and energy applications, including power generation, transmission, and distribution. Both styles have advantages. Circular connectors are a preferable choice for applications in which a cable is passing through a cable tray, and rectangular connectors offer easy customization and reduced use of space.
Q: Why are circular connectors so common in energy applications, if they pose drawbacks?
A: Circular connectors are common in the energy industry because they have been the standard for a long time. Many designers adopted circular connectors for energy applications because they were used in other rugged industries, including military, transportation, and aviation. This does not mean that they are the best solution for every application, though, as the benefits of rectangular connectors often outweigh the benefits of circular connectors. For example, any side-by-side circular connector arrangement requires additional space for accessibility to twist and lock in the connectors. A rectangular connector arrangement does not require as much space in between connectors.
Q: How are today’s connectors different than those in the past?
A: In the past, connectors simply passed voltages between two points. Years ago, many energy applications had a piece of equipment connected to its controller with one on/off signal. Today’s connectors must meet the complex needs of modern systems by allowing the incorporation of multiple media — such as power, signal, coax, Ethernet, fiber optics, and pneumatics cabling — into a single connector. A rectangular connector can easily combine multiple media into a single connector using standard modules that can be arranged into a custom solution. Systems using circular connectors still require separate connectors for Ethernet, fiber optic, and coax power.
Q: What are the main benefits of rectangular connectors?
A: When compared to circular connectors, rectangular connectors are generally less expensive, have shorter lead times, and are more easily customizable. Rectangular connectors also have a better grounding system, which provides more protection against overvoltage, in addition to visual polarization for easy mating and keying features for mismating prevention.
The advantages of rectangular connectors over circular include:
- Off-the-shelf modules for easy, custom designs for any application
- Superior space efficiency
- Modular solutions allow multiple power, signal, and data connections within a single connector
- More termination options: crimp, solder, screw terminal, etc.
- More locking options: single or double-lever and push button
- Ability to connect to other devices, such as a PCB
- Greater contact density possible
- Greater cabling flexibility: top, dual, side, or angled cable entry
- Lower cost
- Surface mount, panel mount, and cable-to-cable compatibility
- Better protection against overvoltage
- Easier visual mating
Q: Which connectors are more reliable?
A: Rectangular connectors are more reliable than circular connectors. While both protect against vibration, the locking elements and seals on rectangular connectors do not allow the penetration of dust and dirt. Rectangular connectors also have a wide array of environmental protection, including UV resistance, corrosion resistance, and up to IP69k protection. This ensures that the connectors will be appropriate for any environment you place it in, and will be operational throughout the entire lifetime of the product.
Q: What advantages can rectangular connectors provide in the energy industry?
A: Rectangular connectors retain all of the advantages that are true for every industry: modular, customizable, lower cost, and space efficiency. However, many energy applications still employ circular connectors where a rectangular connector would be a better solution. These applications adopted circular connections because other industries were using them. While these circular connectors can work effectively, they may not be the best option from efficiency, safety, or price standpoints.