1、Lessons Learned Entry: 0557Lesson Info:a71 Lesson Number: 0557a71 Lesson Date: 1997-07-21a71 Submitting Organization: JSCa71 Submitted by: D. BishopSubject: Test Requirements for Online Maintenance-Free Batteries (including Uninterruptible Power Supplies) Description of Driving Event: A “maintenance
2、free“, lead acid battery, of the set in a Uninterruptable Power Supply (UPS) cabinet, exploded during normal operations. The investigation determined that the 6 year old cell was dry and failed internally; other batteries cells were found void of liquid, as well. Battery condition /capacity was not
3、 observable, due to the configuration with continuous supply of normal facility power keeping the batteries charged.Note: When contacting originator, please refer to Lessons Learned ER-LL-97-01Lesson(s) Learned: “Maintenance-Free“ terminology is misleading; batteries do lose fluid. Manufacturer reco
4、mmendation to perform a battery bank capacity test semiannually had not been performed consistently and reviewed.Recommendation(s): 1. Perform load tests (including battery bank capacity) as recommended by manufacturer and record the load and decay rate.2. Establish a replacement program to minimize
5、 battery failure potential; suggested guideline is when 50% capability is reached. The batteries should be replaced when the low level indicator (usually set by the vendor) is activated (typically at about 50% battery capacity.)3. Personnel inspecting and servicing the UPS electrical and battery com
6、ponents should be protected with face shield, gloves, and acid apron.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: N/AMission Directorate(s): N/AAdditional Key Phrase(s): N/AAdditional Info: Approval Info: a71 Approval Date: 1997-07-22a71 Approval Name: Ronald A. Montaguea71 Approval Organization: NA3a71 Approval Phone Number: 281-483-8576Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
