A UPS’ mission is to ensure a clean continuous supply of power to a critical load. However, this mission becomes impossible if there are single points of failure within your overall power protection plan. UPS systems and associated battery banks rely on other elements such as preventative maintenance and environmental control to ensure they can perform when needed.
Therefore, any power protection plan itself needs to be a comprehensive approach to a power outage. Each aspect needs to be carefully considered to eliminate any single points of failure. Let’s look at some of these individually.
Although not part of the UPS, the environmental control is essential to ensure optimal performance of both the UPS and batteries. The UPS itself can perform comfortably in a temperature range of between zero and 40-degrees C. However, in a room with failing air conditioning, temperatures could easily exceed 40-degrees C, potentially compromising the system and certainly invalidating its warranty.
For VRLA batteries, the optimal temperature range is much narrower. Strings need to be kept between 20-22 degrees C to avoid degradation of their design life.
Continuous checks of the room temperature can be undertaken manually or alternatively can be monitored remotely with a Battery Analysis & Care System (BACS). Operatives are alerted quickly if the temperature is outside of the UPS operating tolerance. Another option would be to introduce redundancy or duty standby to the air conditioning system. Just like having an N+1 or an A and B UPS system, the same configuration can be used for cooling.
The UPS will seamlessly bridge the gap between mains failure and the start-up of a standby generator. One potential area that could cause your plan to fail, could be that the generator won’t start during the loss of mains power. This could be as simple as a flat battery or faulty connections. Preventative maintenance to avoid this issue, is just as important for generators as it is for the UPS and other associated equipment.
During mains failure it would be best practice to remain on generator for long enough to recharge the batteries and ensure the grid has stabilised, to avoid subsequent power cuts and unnecessary switching.
The power protection plan should accommodate these types of worst-case scenarios. Many organisations will identify areas of non-critical and critical load protection requirements and plan accordingly.
I’ve touched briefly on the importance of maintaining equipment. For UPS, batteries and other associated equipment such as air-conditioning, preventative maintenance is equally as important.
For any UPS system protecting a critical load, preventative maintenance visits (PMV) must be carried out by a manufacturer trained and approved engineer. They will have the relevant expertise, access to technical support, firmware updates and spare parts. PMVs will see engineers complete a variety of visual checks to identify early warning signs to prevent any potential failures of important components. However, preventative maintenance needs to be site wide. Generally, organisations complete Integrated System Tests (IST) to identify any factors that could negatively affect the power protection plan. Everything must be checked and tested to ensure it will work when required.
Human error can have the biggest impact on your UPS system and power protections plan. Introducing control measures can help, and for those who need access to areas containing essential UPS equipment, training should be provided. We are talking about AC and DC voltage here, it’s hazardous to humans and a complete understanding of the system and associated risk is a must.
A common occurrence of human error is where an unqualified contractor attempts to maintain or repair a UPS system. This can create more problems than it solves, as not every UPS or installation is the same. Engineers need to be trained on that particular technology and have the correct firmware updates. If not, as well as compromising the integrity of the UPS, warranties will be invalidated.
Remote monitoring can also be beneficial for clients who want to monitor equipment but limit the number of visual checks outside of the preventative maintenance visits. Installing and connecting an SNMP network card is cost effective and simply slots into the UPS. This should be connected to the network to enable monitoring, alarms and any issues to be flagged. One of the most common human errors we come across is that the SNMP card is simply not connected to the network, so issues are missed. If correctly set up, it will provide real-time data from any location and alert you to any unexpected incidents.
We often train site operatives about how our UPS systems function, covering essential topics such as battery isolation or any switching for example: transferring the UPS to external bypass in an emergency. It also means they can understand the importance of and can respond appropriately to any alarms generated by the system with the assistance of our 24/7/365 technical support or until our trained engineers get to site. Training of these key skills can help ensure the operatives’ safety and that the correct procedures are followed to protect other equipment, mitigating the risk of human error further.
For any power protection plan to work, all elements which may introduce single points of failure need to be considered and managed. At CENTIEL we act as trusted advisers to our clients and our experienced team are always happy to discuss your power protection needs. We specialise in removing single points of failure to ensure the load is not put at risk during a power outage. Our clients and our own objectives are aligned: to ensure the UPS can complete its mission and protect the critical load.
Originally featured in Inside Networks Magazine November 2022.