Keeping control of your remote UPS

Electronic equipment used for data processing, communications and industrial control must be protected from electrical disturbances as well as complete power failures. Good-quality uninterruptible power supplies provide both forms of protection very well, but can they also reliably communicate information about their own status, and that of the mains supply to their supported loads and local and/or remote operational managers? In this article, Alan Luscombe, director at Uninterruptible Power Supplies Ltd., a Kohler company, looks at how information essential to UPS monitoring, control and diagnostics can be transmitted across a large site, or many distributed sites, using a Simple Network Management Protocol (SNMP). Enterprises today rely on electronic equipment for their industrial processes, data processing and communications facilities. This sensitive equipment must be protected not only from sudden power outages but also from disturbances that regularly affect mains power supplies and their attached equipment during normal operation – spikes, surges, brownouts and voltage and frequency variations. A correctly-specified uninterruptible power supply (UPS) from a reputable supplier can provide all the protection required – but how can managers and engineers monitor the UPSs, ensuring they remain fit to protect their client load? Especially, how can this function be effectively applied to a number of UPSs distributed around an operational site, or even across several enterprise sites – some maybe unmanned – many hundreds of miles apart? In fact, to ensure the UPS’s success in its role, it must communicate effectively, both with its critical load and a central manager. For example, if the mains fails, the UPS must be able to warn its critical load, allowing an orderly shutdown before the battery autonomy is compromised. Otherwise the autonomy may simply delay a catastrophic crash rather than prevent it. Meanwhile, information transmitted to a central manager about the health of the UPS and its components will reveal impending problems, allowing preventative maintenance before they lead to a system failure. Fortunately the management of unmanned and remote sites across large networks is a widely-recognised issue, for which well-tried solutions exist. Simple Network Management Protocol (SNMP), in particular, was created to address the requirements of wide area network management. Interfacing with major network management systems such as HP OpenView or IBM Tivoli NetView, SNMP is a standard protocol and part of the Transmission Control Protocol/Internet Protocol (TCP/IP) suite which allows all network devices to transmit management variables across enterprise-wide networks. A network manager can monitor all remote sites from one location.