Security light on FCU, is this really necessary?

[IfInDoubtDIY]

I have a non-working PIR light above our garage which I’m planning to replace (see my other posts about this).

The light itself is wired into one of these (fused connection unit):

That’s turned off at the moment as the light doesn’t work. The wire coming out the front (which is in the wrong place) goes to a junction box above the window and then to a piece of T+E which goes into one of these:

It’s connected to the MCB on the right which also controls garage lights. This CU is itself connected to another MCB in the main CU in the house.

I’m thinking that having the PIR light on its own FCU is probably redundant as the MCB for the garage lights will protect it. I’m wondering if it could be replaced with just a regular switch). I don’t need it to be neon as it’s easy to see if the switch is on or not! I suspect the previous homeowners (who were elderly) wanted a neon and the installer thought an FCU was the best way to do this.

Any thoughts?

 

[EFLImpudence]

I’m thinking that having the PIR light on its own FCU is probably redundant as the MCB for the garage lights will protect it.

Correct, although fuses etc. are to protect cables; not appliances.
The CU probably isn't necessary either.

I’m wondering if it could be replaced with just a regular switch).

Yes.

I don’t need it to be neon as it’s easy to see if the switch is on or not! I suspect the previous homeowners (who were elderly) wanted a neon and the installer thought an FCU was the best way to do this.

Who knows?

Any thoughts?

No.

 

[IfInDoubtDIY]

Correct, although fuses etc. are to protect cables; not appliances.
The CU probably isn't necessary either.

Thanks for your input. I am thinking the same about the CU being unnecessary - but then like I said the previous owners were quite elderly and may not have known what was necessary/required.

I’m going to look into replacing with just an appliance isolation switch.

 

[EFLImpudence]

Thanks for your input. I am thinking the same about the CU being unnecessary -

Ok, but it depends on the situation and installation.

The RCD might be required.

but then like I said the previous owners were quite elderly and may not have known what was necessary/required.

It's what people, including electricians, do.

I’m going to look into replacing with just an appliance isolation switch.

I don't really see the point of removing the CU as it is already there.

 

[IfInDoubtDIY]

I don’t really see the point of removing the CU as it is already there.

Allow me to clarify - I’m not planning to remove CU, just planning to replace the FCU with an isolator switch.

 

[Murdochcat]

I would suggest you replace the FCU with a DP isolator, not just a standard light switch

Are you 100% sure it’s not connected to the socket circuit?

 

[IfInDoubtDIY]

I would suggest you replace the FCU with a DP isolator

That’s my thinking.

 

[Murdochcat]

That’s my thinking.

But given the FCU is.a DP isolator - why bother at all?

 

[IfInDoubtDIY]

But given the FCU is.a DP isolator - why bother at all?

Mainly because when I replace the light I’m replacing some of the cable in the garage too. I’m planning to bring the cable through the wall instead of its current route.

 

[JohnW2]

But given the FCU is.a DP isolator - why bother at all?

Quite - so why on earth did you write:

I would suggest you replace the FCU with a DP isolator ...

 

[SUNRAY]

Quite - so why on earth did you write:

Allow me to clarify - I’m not planning to remove CU, just planning to replace the FCU with an isolator switch.

I would suggest you replace the FCU with a DP isolator, not just a standard light switch

I feel a slight misunderstang has snuck in and requires no further comment...


But I will. I also feel replacement of the FCU is not required unless IIDDIY really does not want the neon. By the way theneons were often replacable and therefor easily removable.

 

[IfInDoubtDIY]

I feel a slight misunderstang has snuck in and requires no further comment...


But I will. I also feel replacement of the FCU is not required unless IIDDIY really does not want the neon. By the way theneons were often replacable and therefor easily removable.

Thanks @SUNRAY. I may just leave it and replace it when it needs replacing instead of doing it just for the sake of it.

 

[JohnW2]

I feel a slight misunderstang has snuck in and requires no further comment...

I don't really understand. How does anything else make much sense of the fact that he wrote:

I would suggest you replace the FCU with a DP isolator....

... and then 6 minutes later wrote ....

But given the FCU is.a DP isolator - why bother at all?

... are you perhaps suggesting that his second post was intended as a 'retraction' of the first one (i.e. he was meaning something like "however, having thought properly about it, and given the FCU is.a DP isolator - why bother...?" ??

 

[sparkymarka]

it may be a single pole switched FCU ….

 

[IfInDoubtDIY]

it may be a single pole switched FCU ….

So what would that mean for me then?