This is the eighth in a series of units that will educate you on the part played by a battery in an uninterruptible power supply (UPS) system. IEEE Standard 1187 establishes the recommended practices for the design and installation of valve-regulated lead-acid (VRLA) batteries. The purpose of this paper is to highlight the most significant considerations identified in that standard, including: Safety considerations Design consideration Receiving and installation procedures IEEE 1188, which was discussed in Unit 8, describes the procedures for acceptance (commissioning) tests, including Pretest requirements Test procedures Corrective actions In general, work on batteries should only be performed by knowledgeable personnel who have proper training/certification, proper tools, and personal protective equipment (PPE). IEEE Standard 1657 establishes minimum curriculum for battery technician certification. Prior to any task involving contact with a battery, a job hazard analysis should be conducted to identify any potential hazards that might be encountered. Safety considerations HAZARD NOTIFICATION - Proactive notification of an impending failure is far better than reactive alarms after a failure has occurred. Continuous (real-time) monitoring is an indispensable tool that, when properly used, can detect and predict failures before they turn into fires, melt-down, arc flash, or other catastrophic failures. Battery monitoring should always be installed by certified technicians, preferably prior to commissioning. SHOCK HAZARD - Because most UPS system batteries are rated for greater than 50 Vdc, electrically-rated and/or insulated gloves should be worn. Energized parts, such as terminal posts and intercell connections, should be insulated or shielded; shields should be removable when a section of the battery is being serviced. GROUND FAULT DETECTION - GFD is recommended (or may be required by code) for most battery systems, depending upon the grounding method used. Refer to local codes or IEEE 1187 for guidelines. The UPS design will usually dictate the [...]
This is the seventh in a series of units that will educate you on the part played by a battery in an uninterruptible power supply (UPS) system. Early on in a UPS design a decision must be made on whether batteries should be installed on racks or in cabinets. Both have pros and cons. The following are typical design considerations. Battery technology Vented lead-acid (VLA) (frequently referred to as “flooded” or “wet cell”) batteries, which are sometimes used on very large UPS systems, are ALWAYS rack-mounted. Valve-regulated lead-acid (VRLA) batteries can be mounted on racks or in cabinets. The remainder of this paper will address considerations for VRLA placement. Size Generally speaking, the larger the battery (both physically and ampere-hour rated), the more likely a rack configuration will be considered. There are no hard and fast rules, but typically once a battery unit (single-cell or multi-cell) gets above 100 AH, it favors rack-mount. Below that, cabinet mounting should be considered. Number “Number” refers both to the number of cells in a string, and the number of strings. UPS systems frequently operate at high dc voltages (e.g., 250 to 800 Volts). An analysis must be made on whether to have a minimum number of battery strings using physically large units, or to have multiple strings of physically smaller units. Such decision is outside the scope of this paper, but it would include analysis of reliability (e.g., where and how many could the single-point failures be?) and maintainability (e.g., when is a unit too large for a person to handle, thereby requiring special handling equipment?). Every cell-to-cell connection is a potential single point of failure. Redundancy can increase or decrease reliability, depending upon the number of failure points. Anything over about 23 kilograms (50 pounds) is probably too heavy to lift safely. [...]
Why attention to detail makes a big difference to getting the most out of your UPS battery investment. The global data center business is huge and growing fast, driven by the rapid digitisation of every type of business across almost every nation on earth. Within this scale and growth is the stark reality understood by data center operators – it is a game of small margins. Two facets in particular, installation and commissioning and ongoing monitoring, are key to staying across all the small things that make a difference. The challenge for data center operators is that batteries are a long-term investment during which seemingly insignificant issues can have a material effect on battery life, backup reliability and even facility safety. Installation and commissioning Paying attention to the details starts from the moment a new battery arrives, as careless practice can lead to battery damage. An extreme example is a battery being dropped or mishandled, causing a hairline crack that may not even be noticed. This could be installed at the top or back of a rack, where it is hard to reach and sight, slowly leak and ultimately put the battery into thermal runaway and the risk of fire. At the other end of the scale are simple installation mistakes that can compromise the conductivity of the battery bank. For example, a torque wrench is used for installation at battery manufacturers’ settings to ensure the correct amount of force is used so that a proper connection is made. Failure to do so may cause a high resistance connection causing a hot spot under discharge. Manufacturer’s instructions provide detailed instructions about charging the battery correctly to bring it into service. This includes recommended processes for charging the battery when being installed. Procedures like a discharge test (also known as a [...]
According to a recent study from US-research firm Information Technology Intelligence Consulting (ITIC), over 80% of businesses need 99.99% availability from their data center. ITIC calculate that the average cost of this hour of annual downtime is $USD 260,000. Business owners simply can't afford to be offline, meaning end-to-end reliability and risk management are crucial. Given the huge growth in data storage requirements with cloud access, IoT and big data, minimising downtime is essential. Even a short-lived outage can have a significant impact on a business. Loss of revenue and unhappy customers are the first things that come to mind, and they are critical. The results can be devastating, and that in itself ought to be sufficient to get businesses thinking seriously about their disaster recovery plan. However there are many other significant areas that can be affected by a data center outage. What are the categories of direct costs? These are the actual expenses incurred when a business experiences downtime, and can include: The cost of getting everything back up and running. Depending on the type of business, and how much of it relies on IT, the cost of restarting systems and processes can be significant. Project delays – often projects are linked. If a data center outage means one project is delayed, it can affect others that are tied to it. Equipment costs – especially if there’s been damage to the infrastructure. Third party costs – if contractors or consultants are needed to resolve the outage. When a business owner puts pen to paper and adds up the direct costs alone, they’ll ask themselves: “Can my business afford to be offline?” What about indirect costs? These are costs that can’t be worked out on a calculator, but still have an impact on a business’s bottom line: Loss of [...]
Data centers have nowhere to hide in this digital age, so tools that help them avoid outages and understand exactly how they are performing are becoming critical.
Data centers have nowhere to hide in this digital age, so tools that help them avoid outages and understand exactly how they are performing are becoming critical. For data center operators this makes it really important to clearly understand how their facilities are performing, and any potential threats to their uptime. Any interruption to their service becomes known almost immediately and not only costs revenue but results in dissatisfied customers, lost business and sometimes, irreversible damage to a hard-earned reputation.