A new rugged PLC system from ABB provides an easy-to-implement solution for controlling equipment operating in harsh conditions and extreme climates. ABB’s 'extreme conditions' AC500-XC PLC is protected against a wide variety of threats including high and low temperatures, high humidity, low air pressure, salt mist and hazardous gases, and vibration and shock. This typically reduces system building costs by eliminating the need for sophisticated protective enclosures with special seals, HVAC, shock absorbers, EMC protection, etc.
The embedded protection features ensure that AC500-XC PLC based control systems stay functional and reliable even when operating in hostile environments. Such conditions can be found in many common automation applications including mines, tunnels, vessels, cranes, water and wastewater plants, offshore platforms, wind turbines, solar trackers and weather and navigation stations.
The AC500-XC PLC is a ruggedized variant of ABB's well-known modular AC500 PLC. Almost all of the modules in the extensive AC500 range are available in XC (eXtreme Conditions) variants, providing users with a modular control platform offering almost limitless flexibility and scalability.
AC500-XC PLCs also run exactly the same program code as the AC500, allowing users to migrate to more robust solutions easily, and simplifying development for large systems that require control systems for both standard and extreme conditions. This inter-range compatibility also extends to ABB's safety PLC, the AC500-S-XC. The mechanical dimensions and electrical specifications of connections are also the same as the standard AC500, allowing existing panel layouts and wiring harnesses or designs to be re-used.
Embedded environmental protection opens up extensive applications potential for the ABB AC500-XC. Extended temperature operation allows the PLCs to operate in temperatures from -30 to +70 degrees C, with reliable system start-ups in temperatures as low as -40 C. With few limitations, the AC500-XC operates at up to 70 C. Circuit boards are coated to protect against high humidity levels. The PLC has extended immunity against salt mist and atmospheres with corrosive gases such as H2S, SO2, CL2 and NO2. High levels of vibration and shock can be tolerated, with accelerations up to 4 g from random vibrations up to 500 Hz, or 2 g from sinusoidal vibration. The PLC is capable of operating at altitudes up to 4,000 m. It also offers extended EMC protection against voltage surges and fast transients, as well as electrostatic discharge.
The protection adds a modest margin to the cost of the PLC, but in return it can greatly simplify control system design, often allowing ABB's AC500-XC PLCs to be installed directly in the operating environment without any special enclosures or environmental protection. The savings from this implementation approach can be very substantial. They include reduced design time, a smaller system bill-of-materials, reduced cabling, lower energy consumption from the elimination of the need for cooling or heating, and much reduced lifecycle maintenance, filters and repair costs.
“ABB's extreme conditions PLC allows automation to be sited right where the control I/O is needed,” says ABB’s Thomas Boenig. “The technology opens up new and more profitable design approaches for a very wide variety of automation users.”