UPS maintenance detects faulty battery links


We’ve written before about our use of thermal cameras to improve the level of faults we can diagnose during a UPS maintenance visit.  A recent maintenance uncovered problems with poor crimping on the battery interlink cable lugs.

Power Protect recently won a contract maintaining hospital UPS equipment and were conducting our first maintenance visit when the problem was uncovered.  The UPS had been in service for a number of years already and had been routinely maintained by others so we were somewhat surprised to see that such a fault had gone unnoticed.

The images show two battery links after a 20 minute discharge test with 11 amps flowing.  Fortunately for the site the 40kVA UPS has a very low load.  A higher load would mean much more current and much more heat, this could have been catastrophic to the site.

The fault was initially expected to be due to a loose connection on the battery post however after isolating the battery bank the bolts were found to be correctly torqued.  The links were removed and heat-shrink cut away from the crimp lug to inspect their condition.

Upon cutting away the heat-shrink one of the lugs slipped straight off the cable.  The crimp looked to have been compressed by a chisel strike, rather than using the correct crimping tool which left the connection loose and subject to failure.

The faulty crimps where replaced with new crimp lugs correctly crimped with a hexagonal compression tool.  The correct tool marks the lugs with the size it has been crimped to.  This allows verification that the correct crimp setting has been used.

Is your current UPS maintenance provider as thorough as Power Protect?  Our in-house team of qualified electricians are factory trained in UPS and battery technologies and use modern tools and diagnostic methods to ensure your battery backup systems are available when you need them.  We pride ourselves on our high standard of maintenance and look forward to the opportunity to maintain your uninterrupted power supply equipment.   If you’d like to find out more about our support and maintenance contracts call us on 1300 877 626 or email service@powerprotect.com.au