Sparks Electrical News March 2019

ENERGY MANAGEMENT AND SUPPLY

11

PROGRAMMABLE TIME SWITCHES FOR INDUSTRIAL, COMMERCIAL AND DOMESTIC ENVIRONMENTS

LEGRAND’S Alpharex 3 and MicroRex time switches are designed for easy programming and ensure high-clock precision in industrial, commercial and domestic environments. The devices, with advanced time switch technology, are used to switch an electric circuit on or off at selected times during a pre- programmed time period. These analogue and digital time switches also have an automatic return facility and a permanent forced switch- ing on or off override control. The AlphaRex³ series has a user-friendly standardised text guided programming facility, with a high resolution digital display and backlight. There is a single data key for all devices in the range to allow quick and easy transfer of programmes to other time switches and for creating back-up copies. Programming with clock precision to the second is controlled directly on the time switch, or outside the distribution board using a PC and Legrand’s AlphaSoft programming software. Other features include an EEPROM memory, which prevents settings being lost and the facility to programme the clock prior to despatch. Once the unit has been programmed, the information will remain installed even if the switch is not connected to power. The battery can be removed without having to uninstall the time switch from the distribution board. AlphaRex³ time switches are available with standard and multiple functions, with a daily or weekly programme facility and a clock working reserve of six years. Typical applications include industrial pump stations, security alarms, indoor and outdoor lighting, air conditioners, heating and ventilation systems and swimming pool heaters. The time switches are also compatible with alternative renewable energy systems, like photovoltaic panels. MicroRex time switches offer easy plug and play installation for daily and weekly programming. Simply by setting the analogue switching dial during start up, the time is automatically set using the fast-run mode. In the event of a power failure, the time is automatically reset. MicroRex devices, with analogue and digital dials, are 24/7 time switches for DIN rail and wall mounting, with a five year running reserve. The units have the capability for multiple programmes, which ensures optimum time setting flexibility. MicroRex time switches have an LED status indicator, a precision clockwork of 0.2 s/day and are controlled by either a quartz or synchronous motor. For increased safety and user convenience, there is an automatic and manual and advance/over-ride facility. The series is designed for dependable use in many applications, including periodic lubrication of machines or regularly repeated switching of pumps, feed conveyors and sprinkler systems. The device is also suitable for short periods of controlled defrosting. Other time switches in the Legrand range are designed for precise control in security installations – for access points; electric fences and alarms – as well as for use in industrial installations, including pump stations, filters and conveyors. The time switches are also used to light commercial boards and signage, and for street lighting. Time switches in agricultural applications are used for irrigation and sprinkler systems and for cyclical programmes, like animal feed systems.

ENERGY SAVING WITH THE ZEST WEG GROUP

O perating an irrigation system within the agricul- tural sector can be expensive, with one of the primary factors being the cost of energy. There are, however, ways to reduce costs and achieve savings at the end of the day. Significant savings can be realised by leveraging available technology to provide an appropriate electric motor and variable speed drive combination that will reduce owning and operating costs while providing reliable performance. WEG IE3 Top Premium Efficiency motors and WEG Variable Speed Drives (VSDs), from Zest WEG Group, will do just that. As a supplier with a solid track record in irrigation applications, Zest WEG Group can provide an example to show how energy costs can be reduced. In a pivot pump application which operates for 4000 hours in a single year - relative to two planting cycles – it was possible to do a comparison between a standard efficiency IE1 motor (91 % Eff) and a premium efficiency WEG IE3 motor. WEG IE3 Top Premium Efficiency motors not only offer maximum ingress protection with a higher winding insulation system to increase motor life expectancy, they also offer efficiencies of up to 96.6% and benefits can be seen when compared with IE1 standard efficiency motors. Using a 22 kW 2 Pole at 75 % of full load IE1 motor with an efficiency of 91 %, measured against a WEG IE3 motor with 93 % efficiency, estimated savings of R2100 per year at the current tariff will be achieved. Much higher savings can also be realised by using a WEG VSD in combination with a WEG motor. An IE1 electric motor, again operating for 4000 hours per year at 91 % efficiency, will consume about R 93 800 worth of energy still using old methods by means of valves that can be throttled to reduce the output of water

volume and/or pressure. The same water volume and/or pressure could be achieved using a VSD to reduce the motor speed while simultaneously further reducing the energy absorbed when compared to running the motor direct online from a power source. If a 10% reduction in operational speed using the VSD is assumed, further savings of 22 % to 27 % could be achieved; based on the affinity law principle of hydraulics.

Enquiries: +27 (0)11 723 6000

Enquiries: +27 (0)11 444 7971

status reports and process-related evaluations. ecoExplorer go, a PC- based software with an intuitive user interface, offers simple connection and configuration for measurement devices, and a straightforward display of measured data for quick insight and initial analysis. Weidmuller supports customers and partners around the world with products, solutions and services in the industrial environment of power, signal and data. The company develops innovative, sustainable and useful solutions that set standards in Industrial Connectivity today and continually work toward providing solutions for the technology challenges of tomorrow. The Weidmuller Group owns manufacturing plants, sales companies and representatives in more than 80 countries Phambili Interface, a division of Voltex, is the exclusive distributor of Weidmuller connectivity and interface products in the areas of Industrial Automation, Process Automation and Transportation.

Enquiries: www.voltex.co.za

SPARKS ELECTRICAL NEWS

MARCH 2019