Add light to fused spur

[333rocky333]

Surely if that was likely person A would put a note on the MCB.

Is that your idea of SAFE isolation.

Most alarm installers will not go hunting for an MCB and insist on a FCU by there equipment to work on it safely, its probably also in there regulations or BS4737, size of the MCB supplying it is irrelevant

 

[winston1]

Is that your idea of SAFE isolation.

Most alarm installers will not go hunting for an MCB and insist on a FCU by their equipment to work on it safely, it's probably also in their regulations or BS4737, size of the MCB supplying it is irrelevant.

So how do they install this FCU without hunting for the MCB to isolate the circuit they are going to fit the FCU to?

 

[333rocky333]

They don't they are alarm engineers, they tell the client to get it fitted prior to there instalation.
Obviously some companies have there own trained
engineers do it, but most im sure there responsibility ends at the FCU otherwise it gets complicated.
If the PSU fails in the alarm panel, then a means to isolate needs to be by it to work safely, they are not electricians and i am sure its not in there remit to isolate MCB,s

 

[ban-all-sheds]

That's some spider in the corner!

Call that a spider?

This is a spider:

 

[PrenticeBoyofDerry]

Well, at least we know the circuit isn't on a 6A breaker!

Indeed, still best investigated and established what circuit is being altered, as at some point it will need isolating to work on. Probably the outcome will be that a second fuse connection unit is required.

 

[PrenticeBoyofDerry]

They don't they are alarm engineers, they tell the client to get it fitted prior to there instalation.
Obviously some companies have there own trained
engineers do it

In my experience the alarm engineer fits the FCU and I rarely come across any documentation or testing of the electrical feed, so to say they are trained or implementing that training, would be questionable.

 

[mr rob]

Indeed, still best investigated and established what circuit is being altered, as at some point it will need isolating to work on. Probably the outcome will be that a second fuse connection unit is required.

ok, so so sorry, now finally returning to this project.
The alarm is fed from the left most switch on the CU, the 10Amp one. This feeds the downstairs and upstairs lighting too.

Switch2

• mr rob
• 11 Feb 2018

So what do you knowledgeable people think then? safe, practical thing to do?
this is where i intended to attach it to (the white wire goes to this)

Switch

• mr rob
• 11 Feb 2018

 

[winston1]

Wire it into the MCB via a switch, just like all the other lights.

 

[mr rob]

not sure i can do that. do you mean wire into what ever is behind that left most one? (where i guess the existing wire comes from to the alarm)

 

[John D v2.0]

Assuming you're more confident going in the fcu than the cu, I'd recommend turn off the main switch, chucc the alarm is no longer operating, open the fcu, ideally check the voltage of all terminals to earth is zero, wire a switch in to the supply terminals (l,e only) and the other side of the switch to the live of the light fitting, and neutral and earth directly to the light. Or you can daisy chain the neutral and earth, but that's the basic topology.
As on the first page use a suitable cable outside, also make sure the cable is clipped correctly.
Good luck and let us know any questions

 

[ban-all-sheds]

wire a switch in to the supply terminals (l,e only)

 

[mr rob]

sorry John... what?

 

[John D v2.0]

sorry John... what?

Sorry I was on the bus so the layout isn't the best, but the gist is get an electrician in other words!

 

[mr rob]

i was hoping i could wire in a switch to the light, or better another FCU (or do they do a double FCU?)

 

[winston1]

i was hoping i could wire in a switch to the light, or better another FCU (or do they do a double FCU?)

You don't need another FCU, you are already adequately protected by the MCB.
JohnD has already written:

ideally check the voltage of all terminals to earth is zero, wire a switch in to the supply terminals and the other side of the switch to the light