Simple problem for some....

[fizzbang]

Hi,

if you could help me i'd appreciate it thanks. My electrical knowledge is woeful but i grasp the basics and have tried to give as good an explanation as possible.

Have made up two photos showing my problem and if you know what you are talking about it's a no-brainer i guess.

What i want to do is replace an aging aerial signal booster in the loft. This booster is hard wired into what i believe would be referred to as a fused spur, however i cannot confirm that it is a spur as all i see is the incoming wire. I just suspect that it is as this would probably have been easier at the time it was put in.



In the overview picture you have A + B + C. A is the old booster which needs replacing. B is the cable which supplies power to it, and C is the box which it gets power from.

The next picture is a closeup of the box, C

Wierd, the forum wouldn't let me attach that.

Ok so we have...

1 - Power cable from booster

2 - Live in from house supply

3 - Neutral in from house supply

4 - Live connection to part of doorbell system i think (can be ignored)

5 - Live connection to booster

6 - Neutral connection to booster

7 - Neutral connection to doorbell (can be ignored)

8 - Ground

9 - Again this is just the cable for the doorbell system. The one next to it is cable from the house supply

My question is this - what do i do if i want a new booster which doesn't have such a connection. For e.g. it comes with a plug on the end, and perhaps it's not a standard plug, maybe it's a plug which regulates it to 12 volts or something and therefore is absolutely required in order for the unit to operate.

This is the device i'm looking at - booster

And nowhere does it mention what type of connection it comes with.

Now i was thinking that if i do need a standard 3 pin socket up there to accomodate the new booster then it can't be that difficult to wire a new 3 pin socket into the live and neutral terminals on the box in the roof there can it? My question on that would be do i also need to connect the earth connection to the new 3 pin socket? I guess i would wouldn't i?

How would you pros go about this problem?

Also, why doesn't the existing booster have an earth? Surely it should be earthed shouldn't it?

Thanks in advance guys!

 

[Badger]

not meaning to sound funny or anything but you are obvously unsure of what to do with fitting this new booster to the mains supply, and for your own safety and to make sure the correct testing can be done id recomend you employing a sparky to change over this unit for you. you appear very much out of your depth.

 

[fizzbang]

not meaning to sound funny or anything but you are obvously unsure of what to do with fitting this new booster to the mains supply, and for your own safety and to make sure the correct testing can be done id recomend you employing a sparky to change over this unit for you. you appear very much out of your depth.

Yes i admit i am not good with electrics but this is a fairly simple situation isn't it? I'm just looking at getting power to a new unit but without ordering the unit i am unsure as to what type of mains connection it will have so am trying to pre-empt my options.

As long as you adhere to stict principles such as 1. making sure the power is off first 2. ensuring that your connections are all sound and wires safe (ie not stripped back too much) then provided you have the method straight then is it such a big risk?

At the end of the day the new unit will either be hard wired in the way the existing one is (simplist solution, just rinse/repeat what is currently there) or i need another std uk socket up there into which i can plug a new unit.

I appreciate your answer, and erring on the side of caution, but can it really be that hard to do this correctly?

 

[NozSpark]

If you were to replace the switched fused spur with a socket (also replacing the damaged pattress) how are you going to supply the doorbell?

 

[fizzbang]

No sorry i didn't mean i would replaced the switched fused spur with a socket i meant run a socket OFF that spur in order to provide a standard 3 pin socket for the appliance.

Faesable?

edit: if needed

 

[SPECIAL LOCATION]

Do you know if this is supplied from the a lighting circuit fuse or a socket circuit fuse?

I think the easiest thing to do would be to replace the fused spur with a double socket outlet and just put a plug for your door bell & booster!?

e.g.

Crabtree 13A 2G Double Pole Switched Socket | Screwfix.com

and a double pattress..

Crabtree 2G 29mm Moulded Box | Screwfix.com

Your booster will most likely have a 13a plug arangment of some sort..

But the doorbell supply would need to be flex, not cable, to terminate correctly into a 13 plug!

 

[NozSpark]

And label it up "For doorbell and TV amp only", then never plug anything else into it because if it is off the lighting circuit you could easily blow the fuse or trip the MCB

 

[fizzbang]

Do you know if this is supplied from the a lighting circuit fuse or a socket circuit fuse?I think the easiest thing to do would be to replace the fused spur with a double socket outlet and just put a plug for your door bell & booster!?

e.g.

Crabtree 13A 2G Double Pole Switched Socket | Screwfix.com

and a double pattress..

Crabtree 2G 29mm Moulded Box | Screwfix.com

Your booster will most likely have a 13a plug arangment of some sort..

But the doorbell supply would need to be flex, not cable, to terminate correctly into a 13 plug!

No i have no idea if it's from the lighting circuit fuse or socket circuit fuse. What you're getting at is whether I could put myself in the situation where i put too much load on the wrong circuit (EDIT: in the future if more things were plugged in), yes? That's sensible, thanks i'll see if i can deduce the answer to that if i'm right in my understanding.

Yes i understand what you're saying about the cable for the doorbell to terminate properly into a 13 plug if i were to replace the spur with a double socket outlet.

However, if the new booster came with a standard 13A plug and i snipped that off then could i wire that directly into the existing spur aka the current setup? And if so i'd also have an earth cable in that booster's cable and therefore that would need to be hooked into the earth connection in the spur? Provided that spur does not have a fuse larger than 13A then that should be safe surely?

I'm just worried that any new booster might come with an actual power adaptor on the end of its power cable which would mean that i have to have a standard 3pin socket available to plug it in. There are no sockets currently available in my roof you see.

Thanks for the replies folks.

 

[SPECIAL LOCATION]

Your booster will most likely be double insulated so no earth connection at all...

You most definitely do NOT want a 13 fuse in your spur, as the booster and doorbell will only be small power (e.g. <3A devices).

I would still put a double socket on.. Because if the doorbell went faulty and blew the spur fuse...

you would also lose your TV signal!!!!

whereas if they are both via their own plug tops with 3A fuses in

both TV & Doorbell cannot stop the other one working!!

:| :coffee

 

[fizzbang]

Your booster will most likely be double insulated so no earth connection at all...You most definitely do NOT want a 13 fuse in your spur, as the booster and doorbell will only be small power (e.g. <3A devices).

I would still put a double socket on.. Because if the doorbell went faulty and blew the spur fuse...

you would also lose your TV signal!!!!

whereas if they are both via their own plug tops with 3A fuses in

both TV & Doorbell cannot stop the other one working!!

:| :coffee

Thanks

And the same goes for the doorbell as well - it will most likely be double insulated, hence there is no requirement for a ground cable from it? As you can see from the pictures there does not appear to be a ground cable running from the door bell. Therefore if i run flex from the door bell and terminate into a plug the ground wire would actually be useless? Unless of course someone's done a bad job and i spot the earth connection on the door bell when i take a closer look.....

As per NozSpark's post stick a whacking great "for booster and doorbell only" label on it so noone goes and powers an electric drill from the socket.

Thanks.

 

[Badger]

id hazzard a guess that the 2 twin and earths look like 1.5mm cable so sahould come from the lighting virvuit if they dont and they are from the sockets then it could show/have problems.

 

[Doc Hudson]

View attachment 2702

Welcome to the forum Fizzbang, I think your question has been answered. But I just wanted to say that is a very well laid out question, with good photos making it all very easy for our members to see what you are on about. Do come back and let us know how you get on once you have the new booster.

Doc H.

 

[SLIPSHOD & SLAPDASH]

From the size of the door bell cable it looks like its powering Big Ben

But seriously make sure you turn the circuit off and double check its off. The lights may also go off so you may need a torch.

 

[a1]

Welcome to the forum Fizzbang, I think your question has been answered. But I just wanted to say that is a very well laid out question, with good photos making it all very easy for our members to see what you are on about. Do come back and let us know how you get on once you have the new booster.Doc H.

I'd Second that Doc. Well Done Fizzbang.

Fizzbang, also bear in mind that if you do actually cut any plug off of any item, and that Item needs to be taken or sent back to place of purchase or manufacture, then that warranty may/will highly likely be void.

 

[Apache]

Am I the only person who would sequentially turn 1 circuit off at a time and see when the doorbell stopped working? That way you would know whether it was wired into the lights or the sockets (put a light and the TV on first if your consumer unit (fuse board) isn't well labelled.

If it's on the sockets you can plug whatever you like in.

This is not a suitable means of making sure that there is no power in the box before you start working on it, just to find the circuit to which it belongs.

 

[Badger]

which is why apache i suggested he gets a electrician in as he seemed very unsure on how to go about this swap over.

 

[a1]

Am I the only person who would sequentially turn 1 circuit off at a time and see when the doorbell stopped working? That way you would know whether it was wired into the lights or the sockets (put a light and the TV on first if your consumer unit (fuse board) isn't well labelled.

No Mate, I was going to suggest that too (or watch the TV until the picture went off, lol). But Mrs Admin wanted to go to bed, and my tapping of the Keyboard is rather annoying.

 

[Apache]

But Mrs Admin wanted to go to bed,

You're not going to get a better offer than that!

 

[steptoe]

No Mate, I was going to suggest that too (or watch the TV until the picture went off, lol). But Mrs Admin wanted to go to bed, and I'm rather annoying.

Amen to that,

 

[SLIPSHOD & SLAPDASH]

Tapping of the keyboard