PeterJames Posted January 11, 2018 Share Posted January 11, 2018 As James says a flat 7Ah will draw more power than the PSU is designed to supply, therefore putting unnecessary strain on the transformer, eventually wearing it out. Its like using a Nissan Micra (Your PSU) to tow a fully loaded truck up a hill (Your battery) People often think that bigger is better without taking into account that the current required to charge it when its fully discharged. 1 Quote Link to comment Share on other sites More sharing options...
xt600 Posted January 11, 2018 Author Share Posted January 11, 2018 39 minutes ago, PeterJames said: As James says a flat 7Ah will draw more power than the PSU is designed to supply, therefore putting unnecessary strain on the transformer, eventually wearing it out. Its like using a Nissan Micra (Your PSU) to tow a fully loaded truck up a hill (Your battery) People often think that bigger is better without taking into account that the current required to charge it when its fully discharged. I see what you are saying but will a transformer 'wear out'? I can understand how it may get hotter than it should if it's under too much load but it will carry on working as it should until it eventually burns out, and stops working. Won't it? Quote Link to comment Share on other sites More sharing options...
al-yeti Posted January 11, 2018 Share Posted January 11, 2018 Just now, xt600 said: I see what you are saying but will a transformer 'wear out'? I can understand how it may get hotter than it should if it's under too much load but it will carry on working as it should until it eventually burns out, and stops working. Won't it? What Bout the charging circuit? What's your point? Any component overloaded will drop it's output and heat , so how is that working ? Quote Link to comment Share on other sites More sharing options...
james.wilson Posted January 11, 2018 Share Posted January 11, 2018 5 minutes ago, xt600 said: I see what you are saying but will a transformer 'wear out'? I can understand how it may get hotter than it should if it's under too much load but it will carry on working as it should until it eventually burns out, and stops working. Won't it? the tx will survive the charger wont, have a look at the bored(sic) Its designed for an assumed load, You cannot expect a budget pro panel to take a proper load. Also yes a tx will wear out, if you overload it, they have a design temp and load Quote securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount. Link to comment Share on other sites More sharing options...
james.wilson Posted January 11, 2018 Share Posted January 11, 2018 it will melt the varnish of the windings, but id assume the reg will fail first, taking the br with it, then the tx ideally that will cause an mcb trip, but if your on rewireable fuses who knows. Been many appliancies caused issues Quote securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount. Link to comment Share on other sites More sharing options...
xt600 Posted January 11, 2018 Author Share Posted January 11, 2018 5 minutes ago, james.wilson said: it will melt the varnish of the windings, but id assume the reg will fail first, taking the br with it, then the tx ideally that will cause an mcb trip, but if your on rewireable fuses who knows. Been many appliancies caused issues It should take out the 3A fuse before the MCB, hopefully :-) Quote Link to comment Share on other sites More sharing options...
PeterJames Posted January 11, 2018 Share Posted January 11, 2018 14 minutes ago, xt600 said: I see what you are saying but will a transformer 'wear out'? I can understand how it may get hotter than it should if it's under too much load but it will carry on working as it should until it eventually burns out, and stops working. Won't it? Of course a transformer will wear out, they wear out in normal use let alone when they are being overloaded. Transformers are a moving part in your panel that's the bit that hums, they are vibrating the more they hum the more they are vibrating which is wear. But it also puts a strain on the components the bridge rectifier and diodes that go into making the charging circuit Quote Link to comment Share on other sites More sharing options...
xt600 Posted January 11, 2018 Author Share Posted January 11, 2018 Thanks for all your advice guys, I'll stick in a smaller battery and see how it goes. System has been running for nearly 12 years now, 9 of which it has had the larger battery. Only really started having these issues at the last battery change. Quote Link to comment Share on other sites More sharing options...
xt600 Posted January 11, 2018 Author Share Posted January 11, 2018 3 minutes ago, PeterJames said: Of course a transformer will wear out, they wear out in normal use let alone when they are being overloaded. Transformers are a moving part in your panel that's the bit that hums, they are vibrating the more they hum the more they are vibrating which is wear. But it also puts a strain on the components the bridge rectifier and diodes that go into making the charging circuit That's an interesting concept. I've always understood 'wear' to be caused by the friction of different parts moving against each other. I would've thought a transformer's core, windings and varnish coating would move as one while vibrating. Quote Link to comment Share on other sites More sharing options...
PeterJames Posted January 11, 2018 Share Posted January 11, 2018 Its hard to test the battery without a proper battery discharge tester. The best way to work out the battery size needed is to see what current the system draws and x that by 10 that will give you the minimum battery size required to last for 12 hrs, if you want need it to last longer add another PSU and battery rather than expecting the smaller panel PSU to cope. Quote Link to comment Share on other sites More sharing options...
PeterJames Posted January 11, 2018 Share Posted January 11, 2018 ie 200mA x 10 = 2Ah Quote Link to comment Share on other sites More sharing options...
xt600 Posted January 11, 2018 Author Share Posted January 11, 2018 22 minutes ago, PeterJames said: Its hard to test the battery without a proper battery discharge tester. The best way to work out the battery size needed is to see what current the system draws and x that by 10 that will give you the minimum battery size required to last for 12 hrs, if you want need it to last longer add another PSU and battery rather than expecting the smaller panel PSU to cope. Are you talking about the current drawn while the system is set normally, or the current drawn when all bells an whistles are ringing? Quote Link to comment Share on other sites More sharing options...
xt600 Posted January 11, 2018 Author Share Posted January 11, 2018 *Power Supply Rating It should be noted that the eurösec CPX has 1 Amp available for the full system. However, for the purpose of compliance to EN and PD6662 standard, the capacities of the power supply have to be specified differently. For a Grade 2 system you have 72 hours to charge the battery. With the CPX Control Panel, 90mA is available for battery charging. This defines a theoretical maximum standby battery capacity of 8.0Ah and a maximum of 666mA available for system power. If a smaller capacity battery is used then the rating has to be reduced accordingly. For example: If a 7Ah battery is used it will recharge in 72 Hrs and will theoretically provide 910mA (1000-90mA) for the system. However, the supply rating for that system under PD6662 is still 7.0Ah/12hrs = 583mA. Sounders, detectors and other auxiliary items should be included when calculating current drawn by the system. Quote Link to comment Share on other sites More sharing options...
PeterJames Posted January 11, 2018 Share Posted January 11, 2018 35 minutes ago, xt600 said: Are you talking about the current drawn while the system is set normally, or the current drawn when all bells an whistles are ringing? You wouldnt really need the bells and whistles to ring for 12 hrs now would you Quote Link to comment Share on other sites More sharing options...
PeterJames Posted January 11, 2018 Share Posted January 11, 2018 32 minutes ago, xt600 said: *Power Supply Rating It should be noted that the eurösec CPX has 1 Amp available for the full system. However, for the purpose of compliance to EN and PD6662 standard, the capacities of the power supply have to be specified differently. For a Grade 2 system you have 72 hours to charge the battery. With the CPX Control Panel, 90mA is available for battery charging. This defines a theoretical maximum standby battery capacity of 8.0Ah and a maximum of 666mA available for system power. If a smaller capacity battery is used then the rating has to be reduced accordingly. For example: If a 7Ah battery is used it will recharge in 72 Hrs and will theoretically provide 910mA (1000-90mA) for the system. However, the supply rating for that system under PD6662 is still 7.0Ah/12hrs = 583mA. Sounders, detectors and other auxiliary items should be included when calculating current drawn by the system. Risco will also tell you that a battery in a wireless detector will last up to 3 years I have never known them last more than 18 months. I would never put a 7Ah battery in a panel with a 1amp PSU yep it will charge it, yep the battery will last far longer than a smaller one in a power cut, but those figures do not state the current needed to charge a flat 7Ah battery Quote Link to comment Share on other sites More sharing options...
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