Monty Electrics Posted February 13, 2017 Share Posted February 13, 2017 Hi All Is there a protocol for testing the effectiveness of alarm cable. I have a property which has cable already in place but no alarm and the owner wants me to wire in an alarm. I have no idea how old the alarm cable is or what state it is in. I am familiar with the testing of domestic cable using continuity and insulation resistance testing. Do I just do the same thing for alarm cable to test if it has deteriorated over time? If so what sort of measurements should I get? Thanks in advance for your help. Pete Quote Link to comment Share on other sites More sharing options...
james.wilson Posted February 13, 2017 Share Posted February 13, 2017 yes but as it 50v cable lower the insulation test good cable will give 10 ohms per hundred 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...
Monty Electrics Posted February 13, 2017 Author Share Posted February 13, 2017 Would the lower IR setting on a megger be acceptable - mine is 250V? Or would you use the ohmmeter setting on a multimeter? Thanks Quote Link to comment Share on other sites More sharing options...
sixwheeledbeast Posted February 13, 2017 Share Posted February 13, 2017 Cable will only take 50V max. Multimeter would be my tool of choice. Quote Link to comment Share on other sites More sharing options...
Monty Electrics Posted February 13, 2017 Author Share Posted February 13, 2017 Ok. Thanks. Quote Link to comment Share on other sites More sharing options...
james.wilson Posted February 13, 2017 Share Posted February 13, 2017 as 6wb id rely on a multi meter first 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...
aissecur Posted February 14, 2017 Share Posted February 14, 2017 You could always but a caviat in your quote stating cable routing & installation has been installed by a third party Quote Link to comment Share on other sites More sharing options...
norman Posted February 14, 2017 Share Posted February 14, 2017 As above, the norm would be to make sure the cables meter out, there's nothing obvious maybe lift a couple of carpets near the door jambs to check for damaged, poorly run cables. Once you are happy, make the customer aware they are paying a lot less by you utilising existing cabling and document it and the fact it's not covered under any warranty, on your spec refer to each device as 'utilising existing cabling' too, this is the norm in this type of scenario. Quote Nothing is foolproof to a sufficiently talented fool. Link to comment Share on other sites More sharing options...
datadiffusion Posted February 14, 2017 Share Posted February 14, 2017 I must admit if the existing system is just 'old but not broken' I highlight the no warranty on old cable rule, have a good look for carpet wires etc... and also as each old device comes out, and by the time you view EOL resistance at the panel and measure voltage at each device you've got a good idea of what's what. Quote So, I've decided to take my work back underground.... to stop it falling into the wrong hands Link to comment Share on other sites More sharing options...
PSE Posted February 14, 2017 Share Posted February 14, 2017 Use a 25v / 50v Insulation resistance tester Quote Link to comment Share on other sites More sharing options...
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