
March 16, 2021
If a machine or system is expected to produce potentially hazardous overtravel movements, a combination of safety interlock on the guard and standstill monitor in the switch cabinet can provide the requisite level of safety. The SSW303HV is the Schmersal Group's latest sensorless standstill monitor, offering a significant improvement over its AZR and FWS series predecessors.
A key development goal was universal application of the new standstill monitor, which in total replaces fourteen variants of the previous product range. This is made possible thanks to use of a wide-range power supply for all common AC and DC operating voltages, from 24 V/DC / 24 V/AC to 230 V/AC. The increased temperature range of -25 to +55°C also opens up additional application potential.
A further benefit is its compact design – the SSW303HV takes up just 45 mm of structural width in the switch cabinet. The pluggable, coded connecting terminals ensure rapid, error-free installation, while an additional signalling contact provides information on the error status of the module.
As the standstill monitor operates entirely without sensors, the machine builder no longer needs to intervene with the ‘hardware’ of the surrounding structure. The safety module is connected directly to a three-phase motor and directly measures the frequency of the induced voltage, at rated motor voltages of up to 690 V. The safety contacts for releasing the locking mechanism close as soon as the motor comes to a standstill.
The SSW303HV can be used in safety circuits up to category 4/Performance Level e in accordance with EN 13849-1 and SIL 3 in accordance with EN IEC 61508, with all typical safety interlock designs from applicable manufacturers.
Source
Editor's Pick: Featured Article

New woodlands are being created in the UK with the help of Mid Wales-based Invertek Drives through the Forest Carbon project to offset its carbon footprint. The company, which manufactures variable frequency drives (VFD) at its global headquarters at Welshpool, Powys, has worked with a local printing company to purchase ‘carbon balancing’ paper for all of its in-house printers, including the printing of its products’ handbooks.
Forest Carbon plants woodlands for companies wanting to mitigate the impact of their greenhouse emissions, as well as making a contribution to wider environmental benefits. It is the only UK-based carbon standard and is supported by the government.
The woodlands are planted at locations where they would not otherwise be commercially viable. The paper purchased by Invertek Drives is currently helping plant trees on land near Carlisle, Cumbria.
The new woodlands will not only help capture CO2, but also provide benefits for local biodiversity, landscape, flood management, water quality and recreation.
Referring to companies like Invertek Drives, Carbon Forest states: “These are companies who already avoid and reduce their emissions as far as they can and want to finish the job by capturing the remaining balance.”
Read More
Small motors – both AC and DC – serve as critical points in industrial operations. They may be integral to automation and equipment control and serve multiple purposes to mechanically drive and actuate systems and equipment, but are often replaced rather than repaired or reconditioned.
Larger motors may be repaired, rewound, and sent into a motor rewind pool. However, many motors will simply be replaced when imminent signs of failure are detected using smart equipment, instrumentation, and tools discussed below.
Read More