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Rockwell’s new 1609-P uninterruptible power supplies (UPS) are designed to be assembled in a tower configuration alongside the control equipment they protect.
Phoenix Contact’s Trio Power supplies are shown here in three output versions (left to right); 2.5A, 5A, and 10A.Note that each one can be adjusted for a precise DC output voltage between 22.5 and 29.5 V.The most basic need for control equipment is electric power—power that is “clean,” reliable, stable over a wide range of temperatures and mains voltages, and easily replaced if anything ever goes wrong with it.
Most end users do not think so much aboutthe power supplies they use. The expectation is that control systemsvendors will offer power supplies suitable for their equipment, and even though it is not necessary that end users buy one brand over another, they usually purchase their power supply from their control vendor—provided, of course, that he maintains a competitive price.
Phoenix Contact's power supply combines all the basic functions with highreliability and at the same time, keeps a competitive price. The company also favours a compact size, so when it designed the new Trio Power supplies the new product came out looking like a set of books. The DIN rail single-phase 24 V DC units supply power up to 500W and can operate with a wide range of input voltages between 85V and 264 V AC Theregulated and configurable output current of 22.5 to 29.5 V DC compensates for voltage drops and allows batteries to be recharged. The output currents of 2.5 to 20A can be used without limitations at ambient temperatures of up to 55°C. In this way, loads are reliably supplied with rated values of the power supplies even at high ambient temperatures.
The most interesting statistic about Phoenix Contact’s power supply is the Mean Time Between Failure (MTBF), which is a measure of thequality of the electronic components used to build it. In the case ofthe Trio Power, the MTBF is 500,000 hours—over 50 years of continuousoperation!
Back up power
No matter how reliable a power supply is, it is useless if the mains supply fails. Failure can mean disaster for automated process control systems. Many batch reactors, for example, contain chemicals that if stopped during the reaction, will solidify and be difficult to clean out of the equipment. So not only willit be a loss of processing time and feedstock chemicals, it means theequipment will be out of service for an extended period of time for cleaning and repair. A failure might also be a momentary dip in power or loss of power for a very short time—a few hundred milliseconds, forexample. If it’s enough to cause the electronic control system to fail, then users need to design a strategy to protect themselves from thiseventuality.
In the biopharmaceutical industry, for example, one batch reaction may run for 30 hours, consume hundreds of cubic metres of highly purified water, and in the end produce several kilogrammes of end product worth several million euros. A loss in the operationwould obviously be very costly. So control vendors have to offer theircustomers more than just clean and reliable power: they must offer back up systems to assure their customers that, in the event of a powerfailure, the control equipment will continue to function. Normally theback up service needs to operate only for a few seconds or minutes, until the back up power system begins, or, if that doesn’t happen, thecontrol systems shuts down to a safe state. There are, of course, manyback up power supplies sold on the market, ranging from small units to back up individual personal computers to large units used for backing up large computer systems such as used by banks and financial institutions.
Rockwell Automation says its 1609-U is the only uninterruptible power supply (UPS) specifically designed for industrial applications. The DIN-rail mounted UPS line was launched last year. The newAllen-Bradley 1609-P UPS (photo) is a recent addition to the 1609-U.The 1609-P offers a range of high-density, double conversion online UPS in the 3 to10kVA power range. The 1609-P series units are designed to be assembled in a tower configuration alongside the control equipment they protect, providing back-up power in the event of dips in the supply voltage or complete momentary losses of power.
In the event of a complete power failure, the UPS will enable the orderly shut down of industrial PCs, PLCs, or data logging HMIs. As most owners of PCs know, an orderly shutdown is important; you can’t just push the button and turn off the PC when you’re finished using it. It needs to go through the proper shut down sequence. So the Rockwell UPS provides enough power for the control system to go through the proper shut down sequence so that, once power is restored, a fast system recovery is possible.
When it is in standby mode (which is most of the time) and not working as a UPS, the 1609-P acts as a power conditioner, “cleaning up” the power that passes through it to the control equipment. Itoffers input power factor correction, and tight voltage and frequencyregulation. An intelligent battery management system maximises battery lifespan and performance. If the UPS should fail internally or experience an overload, an automatic bypass automatically diverts power toutility power.
Each model is available in a number of differentinput and output voltage combinations, with all models offering selectable output voltages and a choice of receptacle or hard-wired configurations. The larger models also now come with a Network Management card that allows users with a standard web browser to monitor and controlall UPS units connected to an Ethernet network.
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