burglar alarm rcd

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Chris7

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hi

im looking for a bit of clarification, basically when wiring the alarm into the consumer unit i read somewhere that it should be on the none rcd side is this an outdated way of doing it. i asked a sparky at the factory i work at and and he wasn't 100% but believes everything should be rcd now? heres the quote from 2009

"Via a dedicated breaker on the non rcd side of the CU with an unswitched fused connection adjacent to the main control panel.

Important that it's not connected to an RCD (regs permitting)."

 
hi

im looking for a bit of clarification, basically when wiring the alarm into the consumer unit i read somewhere that it should be on the none rcd side is this an outdated way of doing it. i asked a sparky at the factory i work at and and he wasn't 100% but believes everything should be rcd now? heres the quote from 2009

"Via a dedicated breaker on the non rcd side of the CU with an unswitched fused connection adjacent to the main control panel.

Important that it's not connected to an RCD (regs permitting)."


Your spark at work is doing his bit to continue the spread of electrical myths.  There is no requirement for fused spurs to be RCD protected. There is no requirement for surface fixed wiring to be RCD protected. So providing you don't power your alarm via a cable buried less than 50mm in and wall its not connected via a standard 13a socket then there is no need for any RCD protection on that circuit.

Doc H. 

 
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Thanks guys that's the way I was going. By the way he asked another spark who does more domestic work and he agreed that with him it should be rcd protected as modern alarms come with a back up battery so can nolonger be disabled by "deliberately shorting a socket and tripping rcd" 

Maybe this is a stupid question but am i ok to put the alarm on the last space on CU (without connecting to rcd) and mark it up as no rcd or should i move the rcd along to create a space between the main switch?

 
Or via an rcbo would be best as RCD only to alarm wiring unless a fault happens to the alarm circuit then you'd be unlikely to have a problem with it tripping unexpectedly

 
Thanks guys that's the way I was going. By the way he asked another spark who does more domestic work and he agreed that with him it should be rcd protected as modern alarms come with a back up battery so can nolonger be disabled by "deliberately shorting a socket and tripping rcd" 

Maybe this is a stupid question but am i ok to put the alarm on the last space on CU (without connecting to rcd) and mark it up as no rcd or should i move the rcd along to create a space between the main switch?
I'm guessing that space will be protected by the RCD  ...without seeing it .... so move the RCD along from the main switch to create a NON protected way .     Just mark it up as Alarm  .  

 
Its the same with CCTV because there are ups units which alarm to say a power outage has occured like my DVR at home it's on a ups power unit to save the DVR betting shut down incorrectly 

 
Maybe this is a stupid question but am i ok to put the alarm on the last space on CU (without connecting to rcd) and mark it up as no rcd or should i move the rcd along to create a space between the main switch?


I am not sure what qualifications or experience you have, but it has to be said that we would never recommend any semi-skilled DIYer starts messing around with the internal configuration of a fuse box. This type of work if done wrong could be fatal and should be left to those with appropriate test gear to ensure the protective devices and circuit arrangements for the modifications still meet all the required disconnection times of BS7671. And as a general rule anyone competent enough to do this type of alteration would not need to ask how to do it. Not sure how you would propose doing the first option of your question and the second option I guess you may need an additional neutral bar in the fuse box for the non-RCD circuits(s). However, whilst there is no essential requirement to have an alarm RCD protected, also there is no harm in connecting via and RCD if that is the easiest option. You have just as much chance of an external power cut as a random RCD trip staying off for hours on end disabling the alarm.  

Doc H. 

 
thanks doc, basically when i passed my level  2365 lv 3 the father in law got a bit carried away, bought an alarm and said "you can fit this , save me a few quid" but if you think its out of my ability ill leave it to the professionals but any help/ advice is greatly appreciated if your willing to teach im keen to learn. 

my way of thinking was take a live and a neutral from mains switch, live to mcb on the last space on consumer unit( snap prong off bus bar so not on rcd) then 1.5mm t&e to a 3 amp fuse spur label as alarm no rcd protection the test. would this not be acceptable?

thanks in advance

 
bit of a bodge, I would stick alarm on a RCD protected way before doing that, not that I havn't done such things in the past for various reasons. How about tapping into meter tails with meter tail blocks and adding a mini CU? 

Fitting alarms isn't difficult, just read the instructions, ensure tamper loop is complete, and have a go! 

 
Thanks blinky , it's a texecom premier elite 24 wireless, probably a bit overboard for his house. While my experience is limited I've obviously worked on a a few boards during the two years at the training centre but everything we did was rcd it never came up what to do if we'd need to bypass it. I set up a garage cu with sockets, lights and bought a Metrel Eurotest Easi Multifunction Tester (what we were using in class) so I could practice for the inspection and testing module. I felt confident but It threw me the "non rcd side" without really saying what was meant by this, how to get a live without using bus bar? Its a new build house so the CU and the meter box are back to back on external wall with the tails coming in through the back, not much room for tapping in, that's why I thought take the live from main switch but wasn't sure if this is good practice? Asked the sparks at work the sparky who does domestic work still said rcd it and more industrial sparky said said it would be fine to take the live fro the switch?

 
As I said, you can do the 'bit of a bodge' or you can sometimes get a High Integrity board conversion kit, ie your bodge but with the proper bits, or you can convert the board to full set of RCBOs. But there really isn't anything wrong with having the alarm on an RCD (until RCD trips whilst on holiday and alarm annoys neighbours). Sounds like you have lots of training, but sod all hands on experience?

 
yep that's spot on unfortunately. if id having just done it straight with what i initially thought id have just put it on rcd, but the ocd part of me makes me check and check either again to make sure its 100% best/correct way, last thing i want is someone coming in and saying why hell as he done that!

i think i'll stick to rcd for time being, been googling the lettuced out of the "High Integrity board conversion kit" but i havent got the confidence to do it on my own

cheers for the help and info guys

 
yep that's spot on unfortunately. if id having just done it straight with what i initially thought id have just put it on rcd, but the ocd part of me makes me check and check either again to make sure its 100% best/correct way, last thing i want is someone coming in and saying why hell as he done that!

i think i'll stick to rcd for time being, been googling the lettuced out of the "High Integrity board conversion kit" but i havent got the confidence to do it on my own

cheers for the help and info guys


If there was a spare non-RCD-way on the board use it. Otherwise just bang it on the RCD side. (If it was on a TT installation it would be via RCD anyway).  The reality is that RCD's do not just randomly trip all the time. More likely not trip as mechanise stuck due to no-one doing routine quarterly checks with test button.  Just thinking, personally I can only recall one fault where RCD tripped whilst customer away on holiday over the past 15years,

Doc H 

 
I've had several tripped RCDs whilst customer is on holiday, it seems fridges and freezers have a sense of humour, but it isn't a regular occurrance. The Alarm will have a 20 minute limit on making a racket these days, so it won't annoy neighbours for long.

 
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