More usage options – less cost

Schmersal is launching two new versions of its Safety Fieldbox. This means that the box can not only be integrated into systems with PROFINET/ PROFIsafe as before, but it is now also available for the EtherNet/IP with CIP Safety and EtherCAT with FSoE bus systems.

The benefit this brings is that the designer can now plan the safety functions of a machine in a project regardless of the fieldbus system that is used, as the three versions together cover the most commonly used control systems worldwide.

The Safety Fieldbox from Schmersal enables flexible safety solutions, failsafe and fast installation and maximum process transparency. It also enables easy connection of up to eight safety switchgear devices with plug-and-play. Universal device interfaces for eight-pin M12 connectors allow a wide range of different safety switchgear devices to be connected, including electronic and electromechanical solenoid interlocks, sensors, control panels, light curtains and switches.

Unique features of the Safety Fieldbox from Schmersal include the need for just a single M12 slot for solenoid interlocks and safety light curtains and the connection of control panels with the emergency stop function and up to three non-safe command and signalling devices.

Connecting safety devices via the Safety Fieldbox also helps to save costs, as up to eight devices can be connected to a single Fieldbox, which is much more cost-effective than equipping each individual device with a bus interface.

An integrated digital input on each device slot allows the diagnostic signals of all connected safety devices to be evaluated. This means that safety-related and operational signals, such as those required for diagnostic purposes, can be collected and transmitted. The user can use this information to detect irregularities, e.g. a safety guard that has been moved, and enable prompt intervention if service is deemed necessary. This helps to improve system availability and minimise the risk of downtime. Users can also benefit from greatly simplified, and therefore more costeffective, wiring of safety devices. www.schmersal.co.uk

When it comes to absorbing short peak currents, braking resistors already mounted on the inverter are a good choice. However, when operating inverters, braking resistors can also become thermally overloaded – with costly consequences. A special feature in the COMBIVERT F6 drive controllers from KEB Automation solves this problem.

The trend in plant and machine design is increasingly moving towards the re-use of regenerative energy in the system. Wherever possible, operation in a DC network is used, whereby the energy is actively utilised in the respective application. If the braking energy exceeds the demand of the other axes or if an emergency stop is carried out, braking resistors are always required.

For the COMBIVERT F6 drive controllers (starting from housing size 4), KEB offers sub-mounted braking resistors, which are installed on the rear side of the inverter cooling element. This saves space in the control cabinet and avoids the otherwise necessary wiring effort for the user. The braking resistors are cooled directly via the liquid heat sink, which allows them to absorb significantly more power.

Available as built-in or push-through versions, the liquid-cooled F6 inverters in all device versions have an integrated thermal resistance model that is activated when sub-mounted braking resistors are used and protects them from thermal overload. The monitoring function noticeably increases safety and prevents high costs due to machine failures. www.keb.co.uk

The state space model installed in the F6 drive controllers simulates the temperature of the braking resistor and detects when predefined limit values are reached. If this is the case, the frequency inverter goes into a fault state to prevent possible damage.