Uninterruptible power supplies are typically supplied with 12-36 months warranty and ‘best-endeavors’ response to any alarm conditions. The warranty covers failed electronics and electrical components and any associated labour and carriage costs. The UPS warranty may cover the batteries. It may not. It may be on-site or return-to-base. The warranty may be UPS manufacturer supported or simply a marketing exercise for the UPS reseller who will have to support the ‘extra’ warranty costs themselves.
In a confused market place with a range of warranty offers, it is important to fully investigate the warranty packages available when comparing uninterruptible power supplies. Get it wrong and your critical power installation could be left unprotected for several days. Get it right and you should see a good 5-10 years or more continuous performance from a well-maintained system.
‘Best endeavors’ response is a pretty vague term and in reality it typically means a 3-5 working days response. Push a UPS sales team and you could get a verbal next working day commitment as ‘as we always have engineers in your area’. In reality, if it’s not in writing ‘best endeavors’ means when the UPS supplier has engineers and resources available.
If a site wants a guaranteed response time, the only way is take out a UPS maintenance contract. A contract could offer a 4-clock hour, 8 or 12 working hour response. If the uninterruptible power supply was outside its standard warranty, the contract could also offer cover replacement parts up to a certain value or in their entirety. The UPS maintenance contract is in effective a Service Level Agreement (SLA) and commitment by the UPS supplier to perform to a measurable time period. The contract could also include ‘time to fix’ which is ideal when considering modular UPS systems but somewhat harder to insist upon for traditional mono-block type solutions.
Batteries are the Achilles heel of any UPS system. Most UPS manufacturers will only provide a limited battery warranty and back-to-back any issues to the battery manufacturer. Battery failures within the first 2-3 years of UPS operation are very rare and almost always are down to quality, installation issues or room ambient temperature.
The most commonly used battery in uninterruptible power supplies is the Valve-Regulated Lead Acid battery (VRLA). There are several hundred batteries manufacturers worldwide with some based in the Europe and the majority in the Far East. Quality varies, both in terms of the materials used, manufacturing and testing processes and this is reflected in the pricing and brand reputation. Lithium-ion battery UPS solutions are being developed but as the battery management systems are more complex, the overall system price is still quite prohibitive.
As a guide single phase UPS systems and smaller 3 phase UPS (up to 30kVA) tend to be fitted with 5 year design life batteries (5-65Ah) and larger 3 phase UPS with 10 year design life batteries (80-500Ah plus). A 5-year design life battery has a typically working life projection of 3-4 years before replacement and a 10-year battery one of 7-8 years. This is often reflected in the UPS warranty provided. For example, 5-year design life batteries are typically used in UPS systems with 12-36 month warranties. If a 60 month warranty is required, the battery is upgraded to a ten year design life one but at a cost.
Whilst a UPS system will work up to 40degrees Centigrade (thanks to thermodynamic design and internal fan cooling), battery performance degrades very rapidly when operated for any period of time above 30degrees Centigrade. As a rule of thumb, battery life halves for every 1degree rise about 30degree. The optimum working temperature range is 20-25degree Centigrade (as in a data centre environment). There are implications here for data centre environments looking to follow the ASHRAE standard which could lead to the need to house UPS batteries in air conditioned rooms if white space temperatures are to rise.
When you purchase a UPS solution you are investing in a critical power system that you will want to see in use for at least 5-10 years or more. To achieve this will require a comprehensive UPS warranty and maintenance contract in addition to the use of a high-quality battery set. If you don’t want to take out a UPS maintenance contract you will have to at least consider battery replacement and a preventative maintenance visit to check other components such as the fans and capacitors at some time during the working life of the UPS system.
Whichever service and maintenance approach you adopt it is important to fully understand the warranty conditions and terms provided by both the UPS manufacturer and UPS supplier. The following may prove to be a useful checklist when investigating warranty offers:
The final question concerning commissioning can be another testing area when it comes to UPS manufacturer support under warranty. Commissioning generally applies to hardwired systems requiring electrical installation. Most UPS manufacturers only allow ‘approved’ certified engineers to commission their brand of UPS system and reserve the right to void warranty should a non-approved engineer be used. Again warranty terms need to be checked to verify this if you intend to use your own site or third-party engineers to commission a system. If the system is ‘plug and play’ of course there is nothing to worry about other than following safe working practices as you would with any other electrical device and one that stores energy.
For more information please contact the Eco Power Projects team on 0800 612 7388. As an independent multi-UPS vendor with over 30 years in the UPS industry we are confident that we can provide you with the right power protection solution for your application, supported by a comprehensive UPS warranty and after-sales maintenance package.
EcoPowerSupplies.com
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