Guest G.J.M Posted September 17, 2007 Share Posted September 17, 2007 Cerb beat me to it Link to comment Share on other sites More sharing options...
tinnitus Posted September 17, 2007 Author Share Posted September 17, 2007 It must say Fire Alarm in relation to "a protective device that serves only the fire alarm circuit, butincorporates no switch" - a fused DP spur. The post by 1019641 relates to what I would consider the minimum signage for each device. right, the breaker should say do not switch off. that's what i was led to believe. Link to comment Share on other sites More sharing options...
Guest anguscanplay Posted September 17, 2007 Share Posted September 17, 2007 I thought the breaker had to be locked in its own little red glass box with Fire alarm - do not switch off? but what do I know about fire Link to comment Share on other sites More sharing options...
tinnitus Posted September 17, 2007 Author Share Posted September 17, 2007 I thought the breaker had to be locked in its own little red glass box with Fire alarm - do not switch off?but what do I know about fire as much as me probably agnes Link to comment Share on other sites More sharing options...
Guest anguscanplay Posted September 17, 2007 Share Posted September 17, 2007 as much as me probably agnes which ones you on that family portrait you`ve got as an avatar then ? Link to comment Share on other sites More sharing options...
Guest G.J.M Posted September 18, 2007 Share Posted September 18, 2007 I thought the breaker had to be locked in its own little red glass box with Fire alarm - do not switch off?but what do I know about fire no the mcb can be in a fuseboard but the mcp should be labelled fire alarm do not switch off The isolator for the fuseboard should be labelled warning this switch also isolates the supply for the fire alarm system... The isolator at the fire panel needs to be "lockable" meaning that when you isolate the supply it's locked in postion so that a special tool is required to turn power back on. this is to protect anyone working on the system at the time. Link to comment Share on other sites More sharing options...
arfur mo Posted September 18, 2007 Share Posted September 18, 2007 nothe mcb can be in a fuseboard but the mcp should be labelled fire alarm do not switch off The isolator for the fuseboard should be labelled warning this switch also isolates the supply for the fire alarm system... The isolator at the fire panel needs to be "lockable" meaning that when you isolate the supply it's locked in postion so that a special tool is required to turn power back on. this is to protect anyone working on the system at the time. i'm just being curious here, and i'm bored absolutely titless doing last minut paperwork before i go on holiday - just can't work up any enthusiasm to work on the government's behalf, this thread is as amusing as informative about the proper labeling which is very sensible, imo would be good if alarms could be so labeled, but could possibly compromise security to be totally comfortable with. in intruder as many fire guys will know, we have an un-switched fused spur by the panel which is usually single pole, for now lets not do the single v double pole spurs thingy and just say thats fine. i noted you fire guys have what seems a far more stringently constructed requirement for panel isolator's, even requiring 'secret keys' which i have only noticed on lifts and cranes, and that is an obvious good usage. the questions i have is -: 1) why do you actually need double pole isolation? from my admitted very limited view, surely once you remove the fuse carrier then as you are an engineer and know where not to go sticking your tools and fingers, it's safe as it need's to get to work on. where as say elsewhere an un-trained person 'only' protect by single pole switch and a single pole fuse can have a ball with a ceiling fan or clock. 2) if you had a single un-switched spur the same as intruder, to prevent some clot reconnecting the power as we can do that carrier can be removed and put in your back pocket, by doing so if you forget to refit it (which i have never done in my life ) before leaving, when you get back in the car you will receive a painful (might be enjoyable reminder), and is something i do if i pull the carrier, or i have the clients keys on me for some reason. 3) fire, like alarms the mains only go's upto the transformer, after which you boys work mainly in 24 volts and we go 12 volts, again as most engineers would be happy to work on a properly and safely installed panel with the power applied, so why is there such a high degree of protection? not knocking the extra safety afforded or saying you should do any different, but seems a bit like fitting tractor tyres to your car in the name of safety, so sort where to say it's getting ott?. regs alan If you think education is difficult, try being stupid!!!! Link to comment Share on other sites More sharing options...
Guest Cerberus NI Posted September 18, 2007 Share Posted September 18, 2007 i'm just being curious here, and i'm bored absolutely titless doing last minut paperwork before i go on holiday - just can't work up any enthusiasm to work on the government's behalf, this thread is as amusing as informative about the proper labeling which is very sensible, imo would be good if alarms could be so labeled, but could possibly compromise security to be totally comfortable with. in intruder as many fire guys will know, we have an un-switched fused spur by the panel which is usually single pole, for now lets not do the single v double pole spurs thingy and just say thats fine. i noted you fire guys have what seems a far more stringently constructed requirement for panel isolator's, even requiring 'secret keys' which i have only noticed on lifts and cranes, and that is an obvious good usage. the questions i have is -: 1) why do you actually need double pole isolation? from my admitted very limited view, surely once you remove the fuse carrier then as you are an engineer and know where not to go sticking your tools and fingers, it's safe as it need's to get to work on. where as say elsewhere an un-trained person 'only' protect by single pole switch and a single pole fuse can have a ball with a ceiling fan or clock. 2) if you had a single un-switched spur the same as intruder, to prevent some clot reconnecting the power as we can do that carrier can be removed and put in your back pocket, by doing so if you forget to refit it (which i have never done in my life ) before leaving, when you get back in the car you will receive a painful (might be enjoyable reminder), and is something i do if i pull the carrier, or i have the clients keys on me for some reason. 3) fire, like alarms the mains only go's upto the transformer, after which you boys work mainly in 24 volts and we go 12 volts, again as most engineers would be happy to work on a properly and safely installed panel with the power applied, so why is there such a high degree of protection? not knocking the extra safety afforded or saying you should do any different, but seems a bit like fitting tractor tyres to your car in the name of safety, so sort where to say it's getting ott?. regs alan Hi Alan - we don't make the rules,we just follow them! Link to comment Share on other sites More sharing options...
esp-protocol Posted September 18, 2007 Share Posted September 18, 2007 Hello Arfur....... It stems from the electrical regs that require all electrical equipment to have double pole isolation to allow safe working and maintenance etc. I agree I think its overkill, and if your competent then there is no need for specific double pole isolation. Going back to the original question, if you stick "Fire Alarm - Do Not Switch Off" next to your spur by the panel then no one in the world is ever going to tell you you got it wrong. In the end, your telling whoever needs to know that that under normal circumstances, the ("unswitched") spur should not have the fuse removed, or the "secret" key operated to remove power from the panel. Link to comment Share on other sites More sharing options...
luggsey Posted September 19, 2007 Share Posted September 19, 2007 Double pole is electricially safer if the earthing is TT where neutral potential can rise and fall (Up to 240v!). If the installation is PME/TNCS etc then the neutral potential is clamped at earth potential so double pole is not really useful, if you think about it having single pole isolation on a PME/TNCS installation may be safer as there are two conductors at eart potential...... The regs don't allow for extra knowledge in the electricial field as once upon a time only the sparks installed fire alarms, now it seems like an open field for unskilled workers, one of the reasons I left my last firm..... I am NOT saying that the skilled/unskilled installer will make a better/worse job, we have all heard the stories, just that the skilled sparks will have a better idea of electricial safety, installation methods and wiring zones etc. ----------------------------------------------------------------------------------------------------------------------------------- Life is like a box of chocolates, some bugger always gets the nice ones! My Amateur Radio Forum Link to comment Share on other sites More sharing options...
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