Room cut out security circuit - Page 1
Forum section: electronics / beginners

author: Pexy
author_rank: Newbie
timestamp: April 07, 2016, 01:53:14 pm
content: Hey guy. Today I caused a short cicuit and my parents didn't like that the whole house went out of power till i reseted the main circuit breaker. So, is there something like that that i can install in my room that will thurn off/cut out the power just in my room insted of the whole house if a short out accurres?

author: elecman14
author_rank: Unknown
timestamp: April 07, 2016, 02:03:05 pm
content: You probably should not be playing with mains voltage if you do not know what you are doing. That being said you may want to look into a GFI (ground fault interrupt circuit). If you do not have experience wiring mains you can get extension cords. This is the US equivalent, but something like this with the style of plugs used in your country should be available:http://www.mcmaster.com/#gfcis/=11vmqgu

author: tszaboo
author_rank: Super Contributor
timestamp: April 07, 2016, 02:03:23 pm
content: You should be more careful.Yes, it is called a circuit breaker. I dont know about your local regulations, but I have it for every room separately, and then some. If you already going to ask an electrician to install one just for your room, then please please please make sure to install a ground fault detection breaker also.Or better yet, have an extra outlet with extra circuit breaker, GFD breaker, isolation transformer and everything. I dont know how old you are, but please understand that electronics can kill you in a second, and should be treated with respect and carefulness.

author: Pexy
author_rank: Newbie
timestamp: April 07, 2016, 02:46:11 pm
content: Thanks guys i will look it up. I tryed to fix a snaped cable pin conector with a new one. There are suposed to be black, blue and yelow/green(Europe style) wiers comeing from the device. But in my case there was 2 black and 1 blue so i connected them the wrong way and caused the main circuit breaker to go off and my parents weren''t verry happy about it. So I came here to ask you guys for help.

author: jeroen79
author_rank: Frequent Contributor
timestamp: April 07, 2016, 06:47:11 pm
content: In that case you should have determined which is which before connecting anything together or to the mains."Measure twice, cut once." applies to electricity too.Do you have a multimeter with continuity tester?If you're going to do more experiments then have a seperate group (with circuit breaker and ground fault detection) installed.If your parents won't have that then you can get a circuit breaker that is significantly less than the group's breaker and put that between the mains and your experiment.

author: rstofer
author_rank: Super Contributor
timestamp: April 07, 2016, 07:19:56 pm
content: As the OP discovered, sometimes the main CB trips while the branch CB doesn't (although it should). I guess it depends on the country and their standards but in the US, small molded case breakers will trip at 10x (10 times rating) instantaneously. So, if the main panel had a CB rated at 100A, it will trip instantaneously at 1000A. The typical fault current available at a residence will be several times that value so 1000A is easily available. So, it gets to be a race between the branch circuit CB and the main CB and the definition of 'instantaneous'.GFCI won't help except protect from current flowing to ground - usually through a person's body. That's what they are made for. They don't really work as an overcurrent device. Now, if the fault actually was to ground then, sure, the GFCI will trip the power. But there is still a race with the main CB at this fault level. No guarantees!I'm kind of surprised the main CB tripped but stranger things have happened.

author: Kilrah
author_rank: Unknown
timestamp: April 07, 2016, 07:24:56 pm
content: In one of the places I lived as a kid I remember that breakers would trip regularly, but it was pretty much always be the main one, not the lower current branches.Was too young to care beyond the observation, but thinking back that main breaker must likely have been faulty.