Electricity + Control May 2019

round up SENSORS, SWITCHES + TRANSDUCERS

Time switches delivering high clock precision

a daily or weekly program facility and a clock working reserve of six years. Typical applications for this series in- clude industrial pump stations, security alarms, indoor and outdoor lighting, as well as air conditioning, heating and ventilation systems. The time switches are also com- patible with alternative renewable energy systems, such as photovoltaic panels. The MicroRex time switches offer easy plug-and-play installation for daily and weekly programming. By simply setting the analogue switching dial during start up, the time is automatically set using the fast-run mode. In the event of a power fail- ure, the time is automatically reset. MicroRex devices, with analogue and digital dials, are 24-hour and seven-day time switches for DIN rail and wall mount- ing and have a five-year running reserve. The units have the capability for multiple programs, which provides time-setting flexibility. The 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 in- creased safety and user convenience, there is an automatic and manual and ad- vance/over-ride facility. The MicroRex series is designed for dependable use in many applications, in- cluding periodic lubrication of machines or regularly repeated switching of pumps, feed conveyors and sprinkler systems. The devices are also suitable for short pe- riods of controlled defrosting.

Other time switches in the Legrand range are designed for precise control in security installations as well as industrial installations, including pump stations, fil- ters and conveyors. Legrand time switch- es are also used for the lighting of com- mercial boards and signage and for street lighting. Time switches in agricultural ap- plications are used for irrigation and sprin- kler systems and for cyclical programmes, such as animal feed systems. The range is available nationally from Legrand’s distributor network and the company offers a technical advisory and back-up service. Enquiries: Legrand, Tel. +27 (0)11 444 7971, or email: legrand.south-africa@legrand.co.za

Legrand’s AlphaRex³ and MicroRex time switches are designed for easy program- ming and ensure high-clock precision in industrial, commercial and other environ- ments. Legrand 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. The analogue and digital time switches also have an automatic return facility and a permanent forced switching on or off override control. The AlphaRex³ series has a user-friend- ly standardised text guided programming facility, with a high resolution digital dis- play and backlight.There is a standard, sin- gle data key for all devices in this range, to allow quick and easy transfer of pro- grammes 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 pre- vents settings being lost, and the facility to program the clock prior to despatch. Once the unit has been programmed, the infor- mation remains 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

Legrand’s AlphaRex³ and MicroRex time switches are designed for easy programming and ensure high-clock precision in industrial environments.

Rugged sensors for small-scale process technology

Balluff is expanding its range of sensors for media-contacting temperature detection, in hydraulic power units for example. New to the range are a temperature sensor with display, a tem- perature transmitter and a PT1000 sensor. The version without display is especially compact and vibration-resistant, whereas the version with the turnable and easily readable display offers high operating convenience and flexible installation. Depending on the version, the BFT sensors provide PNP switching outputs, analogue signals 0...10 V /4...20 mA or work as a PT1000 sen- sor. They are simple to install by threading into the process us- ing a standard process connection with G- and NPT threads and they can be integrated using a 4-pin M12 plug on the sensor. Continuous monitoring of process media on machines and equipment contributes to process security. Values that typical-

ly need to be maintained are pressure, level and temperature. When, for example, in a hydraulic system, the temperature of the hydraulic fluid needs to be monitored, this can be done reli- ably using Baluff’s BFT media-contacting temperature sensors. Monitoring the temperature within the hydraulic loop guaran- tees correct fluid viscosity and optimises machine performance. Critical process conditions such as a temperature limit can be controlled directly via the switching output. An analogue output provides continuous measurement results. The BFT temperature sensors also stand out when it comes to monitoring cooling water, lubricants and compressed air, making them ideal for a variety of applications. Enquiries: BALLUFF SA.T. +27 (0)87 004 0800, or email: sales@balluffsa.co.za

24 Electricity + Control

MAY 2019