To ensure the integrity of any Uninterruptible Power Supply, Telecommunications 48V system or generator, command acid batteries should be checked and maintained.
Surprisingly what ever the expense of your Power Protection system, whether it be a stand alone UPS System or Standby Diesel Generators the most typical single point of failure will be the batteries.
High resistance, leakage or open circuits may cause batteries to fail ; Not supplying the expected autonomy or, inside the case of the generator the inability to start out. The Result – loss in the site load. Then suddenly you demand a 24-7 emergency call out engineer.
Uninterruptible power supplies could have internal batteries or housed in separate battery cabinets. Each battery includes a recommended design life, usually 5 years or 10 years, although these are generally optimistic like they do not consider high usage in the UPS Battery system caused by intermittent spikes, brown outs or voltage fluctuations that absorbed from the batteries to shield your mission critical sensitive systems.
Although battery could have an operating life expectancy stated from the manufacturer of typically nearly ten years, if it’s not checked regularly it may and can fail. Inside a string of 32 blocs all it’s going to take is one of the battery to start to be high impedance and also the complete string will certainly be useless like the load will certainly be can not draw the current it requires and consequently the load will certainly be lost and also your critical load will fall over. The old batteries may be removed and new batteries supplied.
The foremost obvious signs of Battery leakage owing to failure inside sealed lead acid battery causing the casing to split may be visible. Other issues of high impedance and open circuit generally are not obvious and require regular checks.
There are a few various kinds of battery construction but they could be loosely divided into to 2 common types-‘wet cells’ and ‘valve regulated lead acid’ (VRLA) batteries (often cited as just ‘sealed lead acid batteries’).
Wet cell battery maintenance may be longer consuming, like the trade off against increased life expectancy is that the higher price of maintenance due to necessity of taking specific gravity readings and ‘topping’ in the cell. A visual check of wet cell batteries should be undertaken on a far more regular basis as any noticeable drop in electrolyte level should be swiftly rectified.
The VRLA ‘lead acid’ battery is much more difficult to envision becoming a sealed battery. The most typical approach to testing, often built into most UPS systems equipment is really a battery self test and that is often performed automatically over a weekly/monthly time cycle. In case the test fails the UPS system will generate an alarm. The key drawback is that if kit is supporting a tiny load comparative towards the capacity in the equipment the battery won’t be worked hard and will prematurely fail.
Greater reliable means of regular testing a battery is either : –
1. By loading the battery to at least one third of their capacity and carrying out a capacity test
2. impedance testing -increasingly popular as it really is non-intrusive.
There are many methods of achieving a similar result but one method usually is to pass a known ac current with the battery and measure the ac voltage and thus, through the use of Ohms Law calculate the battery impedance. These results may be compared using the manufacturer’s recommended value and also by keeping records may be compared a duration of time allowing a replacement programme to become implemented if the battery impedance has reached a preset value.
Which ever approach to battery testing you opt for, regular battery maintenance is usually an integral section of any Uninterruptible Power Supply or Generator standby power protection system.