Terminal blocks family enables precise routing

06 July 2010

Weidmüller's WMF family of terminal blocks offer simple and precise routing and distribution in process engineering plants and power generation facilities. The new family offers robust and uncomplicated connectivity with Plug and Play routing. The terminal blocks facilitate simple organisation of electrical systems.

With its WMF family (Weidmüller Multi Function) Weidmüller is presenting a multifunctional family of terminal blocks to enable simple and precise routing and distribution of signals in process engineering plants and power generation facilities. Boasting a design width of just 5 mm these space-saving terminal blocks combine different functions in a single module -– feed-through, fusing and disconnect functions. Further advantages of this system include an integrated shield or PE connection, three cross-connection channels as well as connections to accommodate BLZ connectors. In conjunction with pre-assembled cable sets and terminated BLZ connectors routing and distributing is a simple matter of Plug and Play. The terminal blocks are equipped with a vibration proof and maintenance-free clamping yoke screw connections as well as extensive marking options to facilitate identification of electrical equipment. Users can also take advantage of Weidmüller's diverse programme of accessories to adapt the WMF family of products to achieve the best possible solution for their application.

Process control systems are deployed in process engineering and power generation systems. Despite the availability of alternative technologies such as remote I/Os and field buses – incoming and outgoing signal connections are often connected via terminal blocks housed in routing and distribution cabinets. A number of advantages favour the use of terminal blocks, for instance they are equipped with an uncomplicated connection technology and ensure a clear arrangement of electrical systems. And by making use of different accessories terminal blocks can be adapted to provide the best possible solution for the respective application. Fuse holders plugged onto terminal blocks protect signal lines, whilst extensive identification marking possibilities take the stress out of service and maintenance tasks as well as facilitating successful troubleshooting.

To facilitate simple and precise routing and distribution of electrical signals the new family of WMF terminal blocks have been designed for deployment in routing and distribution cabinets. As well as equipping the terminals with feed-through, fuse and disconnect functions Weidmüller designed the WMF family with a compact width of 5 mm and a uniform design appearance. The integrated shield or PE connection replaces shield connection equipment or PE terminal blocks. Weidmüller has introduced an innovative solution for routing and distributing signals. Instead of contacting each individual signal by means of a screw connection between the routing levels it is possible to use preassembled cable sets terminated with BLZ connectors. Simply plug the connector onto the terminal block and reduce valuable wiring time. The black-coloured fuse terminals are equipped with a newly developed, robust, pivoted fuse holder.

Changing fuses is an extremely simple procedure, because the fuse can be very quickly replaced when the rotatable holder is open and facing upwards. Precise and safe handling is a clear-cut distinguishing feature in comparison with systems of the same size available to date. An optional LED status indicator on the fuse terminals indicates clearly – the fuse is OK or defective. The LEDs utilised have a high luminous power, minimal leakage current characteristics of <0.5 mA and do not interfere with signals in the control circuit. In addition to the neutral conductor the user is able to collect an additional shield potential across a large number of poles by utilising standard ZQV cross-connectors.

Tried and trusted millions of times over the WMF family of terminal blocks is equipped with a clamping yoke screw connection system. The gas-tight clamping yoke system is shake and vibration proof, maintenance-free and offers both a high and permanent contact force. Utilising the clamping yoke system makes it possible to connect two conductors at a single terminal point. The connection system utilised on the WMF terminal blocks can accommodate the following conductor sizes and conductor cross-sections: solid and flexible conductors between 0.5 - 4 mm², stranded conductors between 1.5 - 4 mm² and conductors with ferrules between 0.5 - 2.5 mm².

Users can take advantage of Weidmüller's diverse programme of accessories to adapt the family to achieve the best possible solution for their application. SIHA 3 fuse holders for 5 x 20 fuse cartridges are available to protect signal lines. SIHA 3 is available with and without a red LED.

Marking channels accommodate unambiguous and clearly visible markings to identify electrical equipment. This design feature serves to increase clarity of the wiring in the routing and distribution cabinet as well as ensuring clear-cut identification of signal circuits.

The family is made of the highly-resistant insulating material WEMID – this is a special thermoplastic from Weidmüller that in comparison with polyamide PA 66 offers an enhanced continuous operating temperature of 120 °C (PA 66: 100°C). At the same time it exhibits improved fire resistance qualities (flammability class V0 (PA 66: V2) in accordance with UL 94.