Maintenance-Free Spring Pressure Connection Technology

Using safe and maintenance-free connection technology can considerably lower investment costs over a system’s entire lifecycle.

Electrical conductors and the quality of their connections determine machine and system uptime – regardless of the complexity of the system’s automation structure or its functions. Electrical connection technology must elevate one feature above all the others: reliability. And it must maintain reliability under all conditions and over the complete lifecycle of the system.

Mechanical engineers and system designers must offer their clients solutions that guarantee a high level of system uptime and reduce the total cost of ownership over the system's entire lifecycle. This places a tremendous amount of pressure on those providing systems to the chemical and process industries, as well as shipbuilding. The components used here must brave some of the roughest environmental conditions and must perform flawlessly, until they are replaced during scheduled maintenance. This is why the importance of the connection technology for all types of electrical connections should not underestimated in mechanical and systems engineering. Ultimately, using safe and maintenance-free connection technology can provide significant levels of investment protection during a system’s lifecycle. From the view of a system engineer or operator, usability should not come at the cost of safe and maintenance-free electrical connections. From both aspects – the connection quality and usability – the type of connection technology is the deciding factor.

Allowances must be made for copper, which has unique flowing characteristics that can be impaired if a screw connection is too tight. Over time, screws loosen, contact resistance increases and the connection becomes impaired. Shocks, vibrations and temperature fluctuations can impair the contact quality of a screw connection. Shocks and vibrations occur commonly in marine applications; temperature fluctuation demands of −40°C to +70°C can occur in control cabinets that are installed in open-air sites located in areas with extreme climates. Conductor specifications, such as stripped copper conductors, or conductors with lamellar or woven structures, also influence contact quality. For instance, conductors formed from a mesh of thin, individual wires are quickly destroyed by screw connections.

In contrast to screw connections, WAGO's spring pressure connection technology provides safe and maintenance-free connections for electrical conductors – and has proven itself for decades. They first demonstrate their advantages during installation and later during use: correctly connected from the start, the spring clamp connections endure even the harshest circumstances. Because contact pressure that embeds the conductor into the current bar is determined by the spring, basically making it “pre-programmed” to always function optimally. The quality of the clamping point remains consistent, despite shocks and vibrations, because the spring automatically compensates for these to maintain connection integrity.

Because the CAGE CLAMP^® connection has a gas-tight clamping unit, WAGO's spring pressure connection technology is ideal for challenging environments. These include applications in chemical or process technologies, or aboard ships and oil platforms where aggressive, corrosive or oily substances are used. WAGO also offers rail-mount terminal blocks for use in hazardous areas. And, because the standard TOPJOB^® S Terminal Block carries all of the necessary approvals for these hazardous locations, system engineers do not need to have an extensive inventory.

Within measurement technology, WAGO's rail-mount terminal blocks represent an inexpensive alternative to specialized – and usually more expensive – terminal blocks for thermocouples. And finally, spring pressure connection technology has proven itself under the most extreme conditions, such as salt fogs, which are an everyday occurrence in marine settings or along coasts. They’ve also proven their ability to withstand humid heat and shock loads up to 500g. The maritime construction industry is increasingly relying on modular designs for their engineering and switching systems; for these systems, large pieces are pre-assembled and wired using cable assemblies.

The advantages arising from this – mainly quick and precise wiring without specialized instructions – are only gained if clamping units and individual wires are correctly and clearly labeled. WAGO offers continuous marking strips, which can be printed with up to three lines of information to ensure accuracy. This allows clear terminal block marking that matches connection points to their respective system parts. Beyond accuracy, this increases wiring safety. Combining clear marking and supreme usability, CAGE CLAMP^® connection technology streamlines wiring – particularly for difficult-to-access applications, such as offshore platforms.

CAGE CLAMP^®-equipped terminal blocks are suitable for all conductor types: solid, stranded and fine-stranded conductors, as well as fine-stranded conductors with ferrules or pin terminals, and tip-bonded conductors. This flexibility pays off, especially if system designers do not know what conductor types they will find while commissioning a switchboard on site. Because the spring's clamping force withstands reuse, CAGE CLAMP^® offers additional safety when used in systems that have long lifecycles and will eventually require some retrofits or upgrades. WAGO's powerful and versatile spring pressure connection technology allows a wide range of conductor sizes to be quickly and reliably connected: Conductors from 0.08 mm² (28 AWG) are safely and quickly secured via CAGE CLAMP^®; POWER CAGE CLAMP connects conductors up to 185 mm² (350 kcmil). Additionally, WAGO not only offers spring pressure connection technology for terminal blocks, but also equips its entire range of automation components with these reliable connections.

WAGO supports the entire configuration process for both electrical interconnect and automation products with the smartDESIGNER online configurator. It has interfaces for EPLAN and WSCAD, among others. This enables bidirectional communication with the CAE system and ensures the integrity of the parts list. Furthermore, as an online application, the software can be easily used without integration into the company’s own IT system. This saves both time and money and is especially advantageous when IT is outsourced to an external service provider that charges for new installations or software updates. If any WAGO electromechanical components and automation systems are used in the switchgear, the designer can conveniently use smartDESIGNER's direct link to WAGO's eShop.

Technical specifications, data sheets and downloads that can be directly accessed from eShop. Once the rail assembly has been configured, it can be audited by the tool, displayed in 3D and documented. It is also possible to output marking for the WAGO components directly using the WAGO smartDESIGNER. Using project-specific approvals, a simple comparison can be performed by both the system designer and by the switchgear manufacturer using the same database. This enables documentation of every step. Which in turn generates transparency and reduces expenses.

Author: Kay Miller