LIBERTY MPS12-XXX series UPS12-XXX series控铅酸 battery user manual
Contents
1. VRLA 4ate sit SE RE2. 4
3. 4 24 55 2VDC 2 22 2 5V C 55 2VDC 22
4. 20 200A 100 10 1 7V C 12 10 6 10 2 8 5 5 1VDC VRLA
5. we FA iL e 10 a TEER E
6. RARE TT an RAM MARLEE RHF RE RAL 2 3V C 25 2 25V C 25 48 72 REER elle ee Ed pina 642
7. T 1 280 1 300 VRLA 77 F 25 e5e 2 25V C 2 30V C 30 12V 6 77 F 25 405 414VDC 0 0028V F 0 005V C 90 F 2 21V C 2 26V C 30
8. VRLA 10 1 5cm Liberty VRLA e2e VRLA
9. 1 2 2 20 85 ede 1 VRLA VRLA 77 F 25 C 70 F 21 C 80 F
10. 2 80W 100 1 80 100 125 1 25 80 80 VRLA 77 F 25 C
11. 1 2 3 100 O oo DD PO gis Oa IE OG ae Be F 4 UPS 10 A U N e P P P TS OO oo N A UAG Dag tn Sees reg OE E 1 2
12. RG 4 Le 100 La RATED CAPACITY 9o Of DY Es Yo FE tk RATED CAPACITY RE 4 PF LT ee e G 30
13. Eich a Haha VRLA NOTELNLacLatt4 1 FR MHF Figue 2 Parallel Strings of Batteries Bel 3 FR th eA tt BE ele 2 3 4 5 6 7 8 VRLA VRLA
14. 77 25 C 18 F 10 C VRLA VRLA 1 VRLA 80 HR HEV Li
15. e6e s so 0 o To ei Ei au me 2 25 2 30V C Figure 3 Float Current Vs Voltage 3 12V 2 30V C 13 9V 13 3 14 5 24 2
16. 10 10 ee 12 RA REA 10 10 e MARM Baak pea reran it 8 e136 Table of Contents General Information Battery System General Description Series string 5 Parallel string 5 VRLA Battery Safety Concerns BlectriGal HazardS ee ee ed 6 Disposal 6 Chemical Hazards Fire Explosion and Heat Hazards Handling Hazards eee Preparation for VRLA Battery Periodic Maintenance Required Maintenance Tools and Equipment 0 7 Periodic Maintenance Tasks and Schedule Quarterly CHECKS se 8 Semi Annual Checks Annual Checks Bi Annual Checks Data Analysis and Corrective Actions Ambiant and Battery Temperature Battery Visual Inspection System Float Voltage Ground Fault Check Float Charging Current Indiv
17. P P 1 5 6 2V P P 135VDC 2 25V C 10 10 12 3 25 C 10 C
18. 397 8 408 6VDC 60 F 30 413 6 422 6VDC 0 5 Vrms 414VDC 180 2 07Vrms 414VDC
19. Caution Do not attempt to remove the vents valves from the LIBERTY VRLA battery or add water This presents a safety hazard and voids the warranty Handling Hazards The individual batteries may weigh from 25 to 100 pounds depending on part number Exercise care when handling and moving batteries Assure the use of appropriate handling equipment Preparation for VRLA Battery Periodic Maintenance There is little difference between the periodic maintenance associated with a VRLA battery and a vented wet cell battery with the exception of that related to the liquid electrolyte Naturally it is not required to measure electrolyte specific gravity or add water to the VRLA cells For optimum reliability it is recommended that the battery system be monitored quarterly If the battery system incorporates an automatic monitoring system to gather the electrical and environmental data the quarterly checks are limited to the evaluation of the recorded data and a visual check of the battery In general the types of checks to be made during the periodic maintenance include 1 System charging voltage 2 Ambient temperature 3 Battery pilot unit temperatures 4 Interunit connection hardware resistance or tightness Individual battery float voltage Momentary high rate load test Battery system capacity test NOM A test of the individual unit resistance impedance or conductance while optional is also recommended on
20. Could result in the Replace the battery emission of hydrogen system and correct the sulfide which is detectable items leading to the themal battery fire and inability to support the load 25e TABLE 1 VRLA Battery Symptoms and Solutions Cou t VISUAL CHECKS Rotten egg odor Possibly caused by high Odor is a product of Replace the battery temperature environment extended thermal system and correct the overcharging excessively runaway items leading to the high recharge current thermal runaway shorted cells or a ground fault or a combination of these items Melted grease at Connections were hot Excessive voltage drop Clean and reassemble the terminals probably due to excessive perhaps leading to short connection if undamaged resistance caused by loose operating time or damaged connection dirty contact terminals Replace any battery with surfaces or corrosion damaged terminals within the connection In extreme case could lead to melted terminal and ignition of the battery cover Corrosion at terminals There is possibly either Increased connection Disassemble connection residual electrolyte resistance and resulting clean coat connecting from manufacturing or increase in the connection surfaces and terminal electrolyte leaking from the heating and voltage drop area and seal with battery terminal seal that at high rate discharge antioxidation grease and is attacking the interunit appropriately reassem
21. 27 C 77 F 25 C 18F 10 C 50 122 F 50 VRLA 18 F 10 C
22. of the unit 10 seconds after application of the test load should be at least 1 7 v c average 10 2 8 5 and 5 1 VDC for 12 10 and 6 volt batteries respectively or the battery should be suspected of being open shorted discharged or of very high resistance and low capacity Never perform the high rate momentary load test on a battery suspected of having a shorted or open cell Full face protection should always be worn during this test since a spark internal to a cell could ignite the residual gasses within the cell More information concerning this test and the minimum voltages to be expected by part number is contained in the pamphlet Integrity Testing 41 7664 Impedance Testing The normal wearout mode of the VRLA battery includes corrosion of the plate grids deterioration of the plate active material and some drying of the electrolyte Abnormal failure modes would include deterioration of the conductive path and excessive drying of the electrolyte These processes will all increase the resistance of the affected cells and periodic measurement of the impedance resistance or conductance of the cells and trending of this data can indicate string uniform gradual degradation and loss of capacity with time This is shown in Figure 4 Rapid changes in individual units may indicate shorted open and drying cells and cells with deteriating conductive paths When an AC ripple voltage appears ac
23. Battery system Float Charging Voltage The recommended battery system float charging voltage for the LIBERTY VRLA Batteries with a specific gravity of 1 280 to 1 300 is equal to the number of cells in the system multiplied by the range of 2 25 to 2 30 volts per cell at 77 F 25 C For example a string of 30 each 12 volt 6 cell batteries should be float charged within the range of 405 to 414 VDC 180 cellsX2 25V C minimum and 180 cellsX2 30V C maximum at 77 F 25 C When temperature extremes are encountered the float charging voltage should be temperature compensated The temperature compensation coefficient is 0 0028V C per degree F 0 OO5V C per degree C For example if the battery normal temperature is 90 F 13 above 77 F the average float charging voltage range should be reduced 0 036 V C 13 X0 0028 VIC per F to between 2 21 and 2 26 V C For a 180 cell battery this would be 397 8 to 408 6 VDC This will help reduce the potential for thermal runaway at elevated temperatures If the battery operates at cold temperatures for example 50 F 17 below 77 F the charging voltage can be increased to improve recharge time For example the charging voltage range could be increased by 17 X 0 0028 V C per degree or 0 048 V For the 180 cell string this would be 413 6 to 422 6 VDC If the battery is undercharged for a period during which there have been multiple discharges the battery will not
24. cleaners will damage the battery plastic containers and could cause them to crack and craze Container and Cover Damage Should a crack or other penetration of the container or cover of a battery be noted it should be replaced A crack in the container could allow conductive electrolyte to wick from the battery and create a ground fault A ground fault could lead to melting and burning of the container A hole in the cover even without wicking of the electrolyte can also be a serious situation The hole will allow drying of the electrolyte in the subject cell resulting in an eventual high resistance and heating of the subject cell Containers which are severely swollen and permanently deformed have been overheated and experienced thermal runaway Thermal runaway will also cause the batteries to gas and dry out and will damage the plates In this case the entire battery string should be replaced Terminals Bent or otherwise damaged terminals can produce high resistance connections or can hide a fracture that could fuse open under load Batteries with damaged terminals should be replaced If the protective grease at a termination has melted and flowed onto the cover it is an indication that the connection has been hot and this is in all probability the result of a loose or high resistance connection In this situation the connection should be disassembled inspected for damage cleaned and properly reassembled 19e
25. fully recharge following each discharge and it will provide progressively lower capacity This condition may be correctable with an extended equalization charge e g 48 to 72 hours However if the situation has continued for too long a time irreversable sulfation of the plates may have occurred and the battery may have to be replaced Extended overcharging will cause excessive float current corrosion of the plate grids gassing and drying of the limited amount of electrolyte This constitutes premature aging of the battery and loss of capacity Severe overcharging for extended periods can induce a thermal runaway condition This would also necessitate replacement of the battery system While measuring the battery system DC float charging voltage it may also be convenient to measure the AC ripple voltage appearing across the battery system If the AC ripple voltage is a sinusoidal waveform the maximum reading should be less than 0 5 Vrms of the DC float voltage In the case of 180 cell string floating at 414 VDC this is 2 07 Vrms When measuring the ripple with an oscilloscope the maximum p p value should be 1 5 of the float voltage or 6 2 Vp p when floating at 414 VDC Excessive AC ripple voltage across the battery could cause gassing and heating of the battery which would result in reduced life Battery System Ground Fault Detection If the rectifier used to charge the battery has a ground fault detection capabil
26. 24 cell system with a nominal voltage of 48 volts CIRCUIT BREAKER Figure 1 Series Connected String of Batteries 1 Multiple strings of the series connected batteries may be connected in parallel to provide a total system with a capacity of the sum of the capacities of the individual strings For example as shown in Figure 2 two each 48 volt 90 ampere hour capacity strings can be connected in JUNCTION BOX BREAKER A f i 0 ies NOTELHL2 L3 L4 Figure 2 Parad Stings of Batteries The LIBERTY VRLA battery is a lead acid battery which facilitates an oxygen recombination cycle The net result is that under normal conditions there is minimal gas emission and loss of water from the electrolyte is immobilized in either a gel form or is absorbed separator between the plates Consequently the battery is maintenance free in terms of electrolyte maintenance that is there is no requirement nor capacity to add water to the cells or to measure the electrolyte specific gravity VRLA Battery Safety Concerns Maintenance and servicing of the LIBERTY VRLA battery should only be performed and supervised by personnel knowledgeable of lead acid batteries and required personal safety and equipment safety precautions Keep unauthorized personnel away from the batteries and maintenance activitie
27. A 2V 6V 10V 12V 1 4 12 24 48V 2 2 48V 90 48V 180 Liberty Je MPS UPS e Reed ne 5 n OF eet AGM Shr She Sh Figure 1 Series Connected String of Batteries 1 VRLA 7 ee u FF
28. LIBERTY SREP ISAS Bh 26 200 Valve Regulated Lead Acid Battery 26 To 200 AMPERE HOURS CAPACITY MPS12 XXX UPS12 XXX AR A F H Maintenance Instructions LIBERTY s STANDBY POWER DIVISION C amp D TECHNOLOGIES INC SHANGHAI C amp D BATTERY COMPANY LIMITED 55 Add No 55 Liandu Road Shanghai Spark Development Zone Shanghai P R C Hot Line 86 21 57505786 Fax 86 21 57505956 R 2 7G BOW 26 200 MPS UPS EID DE RTF ea META ORATE DD ed EEEE Be ROY E AE PEPE A T A T N E T TENAS FEA BU GAs a Bet PE eta acne NN pa Oo hs Oe A Ur UO Oath a ed VRLA Seige a OO oh ee 1 41 7264 2 41 7271 3 41 7135 C amp D LIBERTY VRLA VRL
29. a periodic basis This data and its trend can be a valuable aid in troubleshooting the system and predicting the need for a system capacity test Prior to starting the periodic maintenance activity assure that all required maintenance tools and equipment and safety equipment is available and functional Notify anyone who will be affected by the intended maintenance or troubleshooting activity Also all units in the battery should be numbered so as to facilitate the recording and analysis of data unique to each unit Required Maintenance Tools and Equipment At a minimum the following tools and equipment are required to maintain and troubleshoot the LIBERTY VRLA battery 1 digital voltmeter 2 socket wrenches insulated 3 box end wrenches insulated 4 torque wrench calibrated in in Ibs 5 rubber gloves 6 full face shield 7 plastic apron 8 potable eyewash 9 spill kit 10 fire extinguisher class C The following equipment is optional depending on the type of maintenance to be performed 1 micro ohm meter 2 battery resistance impedance or conductance test set 3 100 amp momentary load test set 4 system load bank DC if to be performed at the battery and AC if to be performed by loading a UPS output el7e Quarterly Maintenance The following checks should be completed quarterly Assure the battery room is clean free of debris and well lighted 2 Assure that all facility safety equipm
30. ance of the batter Undercharging will result in a gradual loss of operation time and capacity with successive discharge cycles If allowed to persist an irreversible level of lead sulfate will develop on the plates with the result of a permanent loss of capacity Overcharging will cause excessive gassing and drying out the electrolyte and will contribute to potential thermal runaway Equalization and boost charging will be less effective and will require extended time Reduced operating time under load Increased float current Heating of cell during discharge Contributes to potential thermal runaway Failure to support the load Could result in an internal arc which could ignite the gasses within the cell eQ7e Reset the charger output voltage to the recommended value Equalize the battery system for from 48 to 72 hours and perform a capacity test If capacity loss is permanent replace the total battery system Reset the charger output voltage to the recommended value If possible reset the charger output voltage to the recommended value or accept longer equalization time Replace the individual battery Replace the individual battery TABLE 1 VRLA Battery Symptoms and Solutions Cou t Symptom Possilbe Causes Possilbe Result Corrective Actions DC VOLTAGE CHECKS CONTINUED DC voltage measured between either of the battery system output terminals and ground rack or a ground fau
31. ble connector the connection If leakage about the terminal area is obvious the battery should be replaced System float voltage Charger output set Overcharging will cause Reset the charger greater than 2 3V C incorrectly excessive gassing and output voltage to the average at 77V 25 C drying of the electrolyte recommended value and will contribute to potential thermal runaway 26e TABLE 1 VRLA Battery Symptoms and Solutions Cou t Symptom Possilbe Causes Possilbe Result Corrective Actions DC VOLTAGE CHECKS CONTINUED System float voltage less than 2 25V O average at77TF 25C System equalize voltage is greater than 2 4V C average System equalize voltage is less than 2 4 v c average Individual battery fl voltage less then 2 2V C average 13 3 VDC for 6 cel 11 1 VDC for 5 cell battery 6 6 VDC for 3 cell battery Individual battery float voltage greater than 2 42 V C average 14 5 VDC for 6 cell battery 12 1 VDO for 5 cell battery battery 7 3 VDO for 3 cell battery Charger output set incorrectly Charger equalization voltage is set incorrectly Charger equalization voltage is set incorrectly Potentially the individual battery has a shorted cell Could be verified with an impedance or conductance check Potentially there may be open cell in the individual battery This can be confirmed by checking for zero float current or checking for a very high imped
32. ce beyond that point when it is at 80 of rating The VRLA batteries are rated at 77 F 25 C It is important to recognize that operation at lower temperatures while it does not harm the battery will reduce the operating time Performance derating factors for reduced temperature are found in the pamphlet Acceptance and Capacity Testing 41 7135 Continuous operation at elevated temperatures will result in accelerated aging of the battery For each 18 F 10 C above 77 F 25 C the battery will age at twice the normal rate Additional information on this topic is found in the pamphlet Life Expectancy and Temperature 41 7329 Summary of Periodic Maintenance for VRLA Batteries The VRLA battery is maintenance free only as related to the electrolyte For assurance of the battery reliability it is still important to perform the recommended periodic maintenance The recommended periodic maintenance whether performed manually or via automated monitoring systems is designed to determine the gradual degradation of the system capacity and to detect any abnormal system or individual battery condition which could impact system reliability 0236 TABLE 1 VRLA Battery Symptoms and Solutions Cou t Symptom Possilbe Causes Possilbe Result Corrective Actions CAPACITUTESTRESULTS Reduced operating time at Normal wear out Eventual failure to support Replace battery system 77F with smooth voltage the load follow
33. ed by when at 80 of rated decline potential for shorted cells capacity or before Reduced operating Individual low capacity Reversed cells during Replace the isolated low time at 77F with step cells discharge_reversed cells capacity batteries voltage decline or voltage will become very hot and plateaus will not fully recharge Excessive initial voltage Battery is cold Heat the battery drop even to the point of dropping load in the first Cabling is too small High Excessive voltage drop Run parallel cables several seconds resistance connections Excessive voltage drop Clean and reassemble eee ee Battery is undersized Add required parallel Shorted cells Cells will become hot Replace isolated units with could develop thermal shorts and evaluate entire runaway internal arcing string could result in explosion CHECKS Elevated room Lack of adequate air Reduced battery life Cool the room or accept Elevated battery Elevated room Reduced life and potential Improve room air Inadequate cabinet Reduced life and potential Improve cabinet ventilation Discharge Charge cycle Can be normal if not Limit recharge current exceeding 181F 10C increase AC ripple current greater Reduced life and potential Determine cause of than 5 amperes rms thermal run away excessive AC ripple IOOAh battery capacity current and correct e24e TABLE 1 VRLA Battery Symptoms and Solutions Cou t Symptom Pos
34. ent is available and functional 3 Measure and record the air temperature within the battery room 4 Visually inspect the battery for a cleanliness b terminal damage or evidence of heating c container or cover damage d evidence of overheating 5 Measure and record the battery system DC float charging voltage at the battery Optionally measure and record the AC ripple voltage at this time also 6 Measure the DC voltage from each polarity of the battery to ground to detect any ground faults 7 lf possible measure and record the battery system DC and AC float charging current 8 Measure and record the temperature of the battery pilot unit Sense the temperature on the side of the unit in the center or at the negative terminal of the unit 9 Measure and record the individual unit DC float charging voltage 10 Measure and record the System Equalization Voltage Semi Annual Maintenance 1 Repeat the quarterly checks 2 Optionally perform the 10 sec high rate e g 100 amp load test to assure the individual batteries are functional 3 Optionally measure and record the resistance impedance conductance of the individual units to trend the condition of the individual units over time and to detect dramatic differences between individual units and the norm Annual Maintenance 1 Repeat the semi annual checks 2 Retorque all the interunit connecting hardware to the values noted in Table 2 This can be o
35. h voltage cell may have an open circuit Shorted cells within the string will lead to increased voltage applied to the remaining good cells in the string and higher folat current For example A 24 cell string charging at 55 2 VDC 2 3V C which has 2 shorted cells will be charging the remaining 22 cells at 2 5 V C 55 2VDC 22 cells and the resulting increase in float current is sure to result in eventual thermal runaway A battery with a shorted or open cell can usually be confirmed by comparing the impedance of the individual units or by comparing the AC ripple voltage measured across the individual units Do Not perform a high rate load test on batteries that are suspected of having a shorted or open cell This would be hazardous since a spark internal to the cell could ignite the internal gases A battery suspected of having a shorted or open cell should be removed and replaced immediately More information concerning the measurement and interpretation of individual battery float voltages is e21e contained in the pamphlet Integrity Testing 4 41 7264 High Rate Momentary Load Test The high rate momentary load test is a functional test of the individual battery within the series string It does not replace a capacity test but it does indicate if the battery is functional at least up to the ampere capability of the test load A typical load used for batteries in the 20 to 200 ampere range is 100 amperes The voltage
36. idual Battery Float Voltage High Rate Momentary Load Tes Battery Impedance Connection Resistance Performance Testing Tables Table 1 Battery System Symptoms and Solutions 3 24 Table 2 Battery Parameters by Model NumbeT 31 Figures Figure 1 Series String of VRLA Batteries Figure 2 Parallel Strings of VRLA Batteries Figure 3 Float Current VS Float Voltage Figure 4 VRLA Battery Impedance VS Capacity and Age SC amp D LIBERTY BATTERY MAINTENANCE AND APPLICATION RECORDER scseeeeeeeees Cover three Appendices Appendix 1 VRLA Battery Periodic Maintenance Data Recording Form pp cover ej4e DYNASTY VRLA BATTERY SYSTEM PERIODIC MAINTENANCE AND TROUBLESHOOTING GUIDE General Information This pamphlet provides a guide for use during periodic maintenance and troubleshooting of the LIBERTY VRLA batteries of 20 through 200 ampere hours capacity Other instructional pamphlets which can be used in conjunction with this guide include 1 Integrity Testing 41 7264 2 Ilmpedance and Conductance Testing 41 7271 3 Acceptance and Capacity Testing 41 7135 C amp D LIBERTY VRLA Battery System General Description In general the battery system is a group of 2 bolt cells of 6 10 of 12 volt batteries connected in a series string to provide a total system of higher voltage For example as shown in Figure 1 four of the nominal 12 volt batteries may be connected in series to provide a
37. is an open circuit in the battery string If the float current is higher than anticipated it may be due to elevated termperature of the battery or shorted cells within the string In either case the cause should be determined and corrected Elevated temperatures and shorted cells are both situations which can lead to thermal runaway Individual Battery Float Charging Voltage While the battery string may be charged at an average of between 2 25 and 2 3 volts per cell not all cells will float at the exact average vlotage Each cell has a somewhat different impedance and rate of oxygen recombination and will therefore exhibit a slightly different float slightly different float voltage at the same float current For example all the 12 volt batteries in a string charged at 2 3 volts per cell will not float at 13 9 VDC but may vary from 13 3 to 14 5 and still be normal If the system is equalized for 24 hours upon installation or with an extended time in float service this spread in float voltage will normally decrease Table 1 indicates the minimum and maximun DC float voltages to be measured across batteries in a series string If an individual battery measures too low it may be an indication of a shorted cell If an individual unit measures too high it may be an indication of increased resistance within the cell If one unit measures very high while the balance of the units in the string indicate near the open circuit value the hig
38. ity the indicator should be observed to determine the safety of the system If a ground fault is indicated it should be isolated and corrected prior to further maintenance on the battery system If the rectifier does not have a ground fault detection circuit use the digital voltmeter and measure the voltage from each polarity of the battery to ground the grounded rack or cabinet A detected voltage would indicate a short or leakage current from the battery to ground The approximate location of the cell with the ground fault from the battery system output terminal would be the measured voltage divided by the average per cell charging voltage For example if the measured voltage to ground was 135 VDC and the charging e20 voltage was 2 25 V C the ground fault would be approximately 60 cells ten 12 volt units from the battery system output terminal Battery System Float charging Current If the DC float current can be measured it can provide an indication of the proper current acceptance of the battery system Depending on the charging voltage per string and the temperature the float current per string should be approximately that shown in Figure 3 The float current will approximately double for each 18 F 10 C above 77 F 25 C AGM GELLEO Milliampere Float Current Per Ampere Hour Capacity Figure 3 Float Current Vs Voltage If the DC float current is zero there
39. l arc should occur during battery with the verified via the float voltage check discharge it could ignite the gasses open cell or or AC ripple voltage or impedance internal to the cell repair the open check of the individual batteries If there is a open loose connection loose external in the external conductive path connection it could damage the termination under load Float current Batteries are not yet fully Not at 100 of capability Determine exceeds 3 0 Millie the specific amperes per ampere cause and hour of rated take necessary capacity at 77F 25C Depending on the degree the Thermal runaway results in corrective Jat float voltage battery may be entering or in eventual meltdown of the battery action thermal runaway and the potential of hydrogen sulfide emissions and fire AC ripple current Poor filtering of the charger Excessive AC ripple current will Improve the exceeds 5 amperes result in battery heating reduced charger output per 100 Ah rated service life and potential thermal filtering battery capacity runaway HIGH RATE 10 ee Terminal voltage is Battery is perhaps not fully Perhaps reduced operating time Fully recharge marginally below the charged or is an older battery the battery minimum voltage that has been in service and is of specified for 10 sec somewhat lower capacity point Terminal voltage is Battery is discharged or battery Reduced operating time Charge and significantly below cond
40. lt indicated by automatic monitoring equipment Damaged battery container allowing electrolyte to wick out to the grounded surface rack Personnel shock hazard Determine the source which could result in serious injury or of the ground fault and replace battery electrocution Potential burning of the container at damaged area or battery fire AC RIPPLE VOLTAGE CHECKS AC ripple p p voltage on the system is greater than 4 of the value of the DC float voltage Individual battery in string exhibits AC ripple voltage of twice that of the other typical batteries in string Poor filtering of the charger output Battery with the high AC ripple voltage has a proportionately higher impedance and should be further evaluated for performance Subject battery could have a deteriorating conductive path or a dry shorted or open cell Excessive AC ripple could Improve the charger cause the battery to cycle output filtering at the ripple frequency and result in heating and deterioration of the plate active material Reduced operating time Verify the battery condition and replace as required Potential conditions could be conducive to thermal runaway eeI28 TABLE 1 VRLA Battery Symptoms and Solutions Cou t aor FLOAT CHARGING ee Float current to the A battery or connection in the Failure to support the load If an EE the string is zero series string is open This can be interna
41. mitted if the connection resistance is measured and found to have not increased more than 2000 from the value at installation Bi Annual Maintenance The battery should be capacity tested every two years at the service load or at the battery rating related to the service requirements Ldeally this will be the same rate at which it was acceptance tested when originally installed Once the battery is found to be at 85 of rating it should be capacity tested annually Capacity testing instructions are found in the bulletin Acceptance and Capacity Testing 4141 7135 Data Analysis and Corrective Actions The data accumulated during the periodic maintenance activities should be recorded on a form such as shown in Appendix One Following is an explanation of how the data would be interpreted and the correction action to be taken However it must be recognized that this explanation is not all inclusive and the analysis and corrective action decision must be made by personnel familiar with VRLA batteries and their operation and failure modes e18 Environment Ambient and Battery Temperature While the VRLA battery wil function at extremes of temperature it is rated at 77 F 25 C and the ideal operating temperature range for the VRLA battery is 70 2JfC to 80 F 27 C Operation at cooler temperatures will reduce the anticipated standby operating time while operation at warmer temperatures will detract from the batte
42. ontain lead and dilute sulfuric acid Dispose of in accordance with Federal State and local regulations Do not dispose of in a landfill lake or other unauthorized location Chemical Hazards Any gelled or liquid emissions from a VRLA battery is electrolyte which contains dilute sulfuric acid which is harmful to the skin and eyes is electrically conductive and is corrosive If electrolyte contacts the skin wash immediately and thoroughly with water If electrolyte enters the eyes wash thoroughly for 10 minutes with clean water or a special neutralizing eye wash solution and seek immediate medical attention Neutralize any spilled electrolyte with the special solutions contained in a pill kit or with a solution of 1 lb bicarbonate of soda to 1 gallon of water Fire Explosion and Heat Hazards Lead acid batteries can contain an explosive mixture of hydrogen gas which can vent under overcharging conditions Do not smoke or introduce sparks in the vicinity of the battery Prior to handling the batteries touch a grounded metal object such as the rack to dissipate any static charge that may have developed on your body Do not charge batteries in a sealed container The individual batteries should have 0 5 inches of space between the batteries to allow for convection cooling If contained assure the container or cabinet and room have adequate ventilation to prevent an accumulation of potentially vented gas e16
43. ross a string of batteries it will be subdivided S 100 La 4 amp sF o RATED CAPACITY a g 85 80 130 3207 irg eor1 Snot nn IMPEDANCE 60Hz z 3 100 l A 90 CONDUCTANCE sot 10 20 30 40 50 60 70 80 90 100 LIFE Figure 4 VRLA Battery Lmpedance and Conductance VS Capacity and Age across the individual units in the string proportional to their relative resistance Therefore in the absence of an impedance resistance or conductance test set the AC ripple voltage across the individual units can be measured with a DVM and compared to each other and the norm as an indication of their relative resistance and condition If the resistance of the batteries has increased by 300 over that when it was new the battery should be further tested to determine the cause and if necessary the battery or system should be capacity tested to assure reliability More information on this topic is contained in the pamphle Impedance and Conductance Testing 41 7271 Interunit Connecting Resistance High resistance in the interunit connections and loose connecting hardware can cause excessive voltage drop during discharge resulting in reduced operating time and in the extreme case even cause melting of the battery terminals and potentially a fire ee The contacting surfaces of all connections should be brushed clean removing all lead oxide and contamination protected wi
44. ry life and will increase the potential of a thermal runaway condition The battery will experience a 5000 reduction of life for each 18 F 10 C above 77 F 25 C High ambient room temperature should be corrected through the use of appropriate ventilation and air conditioning The VRLA battery should not be charged at temperatures exceeding 122 F 50 C A thermal runaway condition could result The individual batteries within the string should not exceed the ambient temperature by more than 18 F 10 C If the entire battery or individual units temperatures are excessively high the respective units may be experiencing thermal runaway In this situation the charging current should be terminated and the cause of the situation should be determined and corrected If thermal runaway has occurred the battery system should be capacity tested and replaced if necessary Battery Visual Inspection Container Cleanliness It is important that the individual batteries be clean and properly spaced An accumulation of dirt or dust and moisture on the covers can produce a conductive path between the terminals or to ground which could result in short circuits or ground faults When batteries are cleaned they should be on open circuit For cleaning use a cloth moistened in a solution of bicarbonate of soda and water Do not use cleaners of unknown solutions such as window or glass cleaners and solvents Use of certain petroleum based
45. s e15e Electrical hazards Battery systems present a risk of electrical shock and high short circuit currents The following precautions should be observed when maintaining VRLA batteries Remove all personal metal objects watches strings etc Use insulated tools N 3 Wear full eye protection and rubber gloves 4 Observe circuit polarities 5 Do not make or break live circuits 6 Prior to handling batteries on a metal rack assure the battery is not inadvertently grounded by observing the ground fault detector indicator In its absence measure the voltage between the battery and the rack It should be zero If not determine the cause and correct prior to proceeding 7 Do Not lay metal tools and hardware on top of the batteries 8 As appropriate use an insulating blanket to cover exposed portions of the battery system when performing extended maintenance that could result in personal or equipment contact with the energized conductors Certain types of rectifier circuits used in charging the VRLA battery may not include a line isolating transformer In these cases extreme caution should be exercised when maintaining and collecting data on the battery system The VRLA battery is sometimes enclosed in cabinets with very limited access Again extreme caution must be exercised when maintaining and collecting data on the battery system Disposa Lead acid batteries are to be recycled Batteries c
46. silbe Causes Possilbe Result Corrective Actions High current recharge High charging voltage Shorted cells This combination can lead Limit recharge current to thermal runaway Reduce to within specifications Replace shorted cells and evaluate total string VISUAL BATTERY CHECKS Cover container crack Cover container explosion Burned area on container Permanently deformed swollen container Handling or impact damage Ignition of cell internal gasses due to external source fusing of internal Cell dry out or ground ace damaged unit fault Potential internal gas ignition Personal injury and Replace damaged unit equipment damage at time and evaluate the balance of explosion of string conductive path or internal Failure to support load spark due to shorting This potential exists for batteries not maintained and continued in service beyond useful life Crack in container wicking Could result in personal Clear the ground fault and electrolyte to grounded rack etc Ground fault Thermal runaway possibly caused by high temperature environment overcharging excessively as a rotten egg odor runaway condition high recharge current shorted cells or a ground fault or a combination of these items hazard due conductive replace defective unit path to rack etc Evaluate balance of the Could result in smoke or a string battery fire Could result in a thermal runaway
47. t surface areas terminal resistance operating time grease the contact surfaces with antioxidant grease and reassemble Repetitive cycles resulting Loose connections can Retorque the connection in heating and cooling of result in heat damaged or as required connection can result in melted terminals during relaxation of torque and high rate discharge an increase in connection resistance ee30
48. th a special antioxidation grease and tight The connection hardware may loosen somewhat with time and repeated cycling of the battery system The connection hardware should be retorqued to the value indicated for the battery part number as shown on the relevant data sheet Asummary of the battery terminal types an the recommended torque values is given in Table 2 Performance and Capacity Testing When the battery degrades to 8000 of its rating it should be replaced That is if a battery system could support 100 amperes for 1 hour when new it should be replaced when it can only support 80 amperes for the same 1 hour period If 100 amperes is the actual load and this must be supported for a minimum of one hour the battery should have been originally sized to provide 125 amperes for the one hour when new This sizing factor of 1 25 is referred to as the aging factor when originally sizing the battery When the battery capacity declines to 80 of rating is it an indication that the plate grids are corroded and expanded that the plate active material has deteriated and that the drying of the electrolyte has occurred The battery should be removed from service and replaced at this time Naturally the other criteria for battery replacement is when it no longer supports the load for the minimum required time even if the battery is still greater than 80 of rating However even at minimal load the battery should not remain in servi
49. uctive path plate grid or Conducive to thermal runaway retest battery the minimum voltage active material or electrolyte Will not support load or replace as specified for 10 sec volume deterioration required 296 TABLE 1 VRLA Battery Symptoms and Solutions Cou t Symptom Possilbe Causes Possilbe Result Corrective Actions AITERY IMPEDANCE CONDUCTANCE TEST mpedance resistance increase by 50 from original values when new or conductance decline to 50 or the value when new CONNECTION HARDWARE RESISTANCE TIGHTNESS CHECK Connection resistance increase of 20 or more from original value Connection hardware tightness is less than the specified retorque value Battery is discharged Reduced operating time Charge and retest battery or Battery conductive or replace as required path plate grid or active material or electrolyte volume deterioration Shorted cells Conducive to thermal runaway Open cells Will not support load Repetitive cycles resulting Loose connections can Retorque the connection in heating and cooling of result in heat damaged or as required connection can result in melted terminals during relaxation of torque and high rate discharge an increase in connection resistance Contamination within the Excessive voltage drop Correct the source of connection can result during high rate discharge contamination clean the in corrosion and high and resulting reduced contac
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