A few questions regarding electrical installations

[kwil69]

Hi, can anyone help with the following questions?

1. Supplementary bonding – does a normal domestic electric shower require supplementary bonding? Or do you connect supplementary bonding from the copper pipes in a bath to the earthling terminal of the shower? Do you connect supplementary bonding to the shower supply pipe even if its not exposed in the same room? Also should there already be supplementary bonding on the bath pipes? A brief and simple explanation might help here, as I just don’t understand what the requirements are. pref in layman’s terms.

2. When fitting a consumer unit to an external garage, where do you connect the consumer unit to? Do you treat like a new circuit from the existing consumer unit in the house? If so what size mcb should I use, or should I use RCD integrated or separate from the consumer unit? Again would be grateful if it could be explained clearly.

3. Outside pir security light – should the cable that trails along the outside wall be protected? Currently the cable is pvc sheathed twin & earth just clipped to the wall. It is out of reach from accidental damage but is it sufficient?

 

[ban-all-sheds]

1. Supplementary bonding – does a normal domestic electric shower require supplementary bonding? Or do you connect supplementary bonding from the copper pipes in a bath to the earthling terminal of the shower? Do you connect supplementary bonding to the shower supply pipe even if its not exposed in the same room? Also should there already be supplementary bonding on the bath pipes? A brief and simple explanation might help here, as I just don’t understand what the requirements are. pref in layman’s terms.

But you already know all this - you told us so here a few weeks ago.

2. When fitting a consumer unit to an external garage, where do you connect the consumer unit to? Do you treat like a new circuit from the existing consumer unit in the house? If so what size mcb should I use, or should I use RCD integrated or separate from the consumer unit? Again would be grateful if it could be explained clearly.

There are a number of options - this topic has been covered countless times on the forum, do a search.

I do wonder though, given the apparent level of your knowledge and understanding, why you want to know about installing CUs and new circuits in a garage...

3. Outside pir security light – should the cable that trails along the outside wall be protected? Currently the cable is pvc sheathed twin & earth just clipped to the wall. It is out of reach from accidental damage but is it sufficient?

T/E is not very suitable for use outdoors if it's exposed to sunlight, weather etc. - you should change it to something more suitable.

 

[kwil69]

This is to do with my brothers property, I am currently studying electrical and like most people some clear understanding makes better sense rather than assuming. Im thinking in practice as well as theory! All I want is guidance please

 

[ban-all-sheds]

Maybe I'm being dim, but I really don't see what guidance you need or why. You told us here a few weeks ago that you had upgraded your wiring as per regs, including the supplementary bonding.

OK - it was in your house and not your brother's but if you know what the regulations on supplementary bonding are then you know the answers to all of the questions you asked....

 

[333rocky333]

When fitting a consumer unit to an external garage, where do you connect the consumer unit to? Do you treat like a new circuit from the existing consumer unit in the house? If so what size mcb should I use, or should I use RCD integrated or separate from the consumer unit? Again would be grateful if it could be explained clearl

Depends on what you use the garage for
I would say a 30 amp supply may be enough , if possible wired from its own rcbo in the house consumer unit,
Obviously the cable size etc will vary to each site and will need working out,as a guide only, 6mm 3core swa may be sufficient and would last a long time,

 

[333rocky333]

3. Outside pir security light – should the cable that trails along the outside wall be protected? Currently the cable is pvc sheathed twin & earth just clipped to the wall. It is out of reach from accidental damage but is it sufficient?

This has cropped up many times
I personally do not rate T+E outside and it also looks tacky
Others will have different opinions

Certain cables degrade and just the colour can affect its reaction to sunlight etc
AFAIK some of these concerns are now adressed in the 2008 regs

 

[kwil69]

The shower circuit in my house was straight forward but my brothers house isnt! Do i really have to explain my reasons for asking about something that im not 100% sure about? Please I only want some guidace. No your not dim, quite the opposite! But you are very analytical lol

 

[kwil69]

When
Depends on what you use the garage for
I would say a 30 amp supply may be enough , if possible wired from its own rcbo in the house consumer unit,
Obviously the cable size etc will vary to each site and will need working out,as a guide only, 6mm 3core swa may be sufficient and would last a long time,

Thanks for the advice

 

[kwil69]

3. Outside pir security light – should the cable that trails along the outside wall be protected? Currently the cable is pvc sheathed twin & earth just clipped to the wall. It is out of reach from accidental damage but is it sufficient?

This has cropped up many times
I personally do not rate T+E outside and it also looks tacky
Others will have different opinions

Certain cables degrade and just the colour can affect its reaction to sunlight etc
AFAIK some of these concerns are now adressed in the 2008 regs

Thanks for that mate. Can you recommend a suitable cable? And also should i connect it to a fused spur? the existing cable is connect directly to the consumer unit with its own mcb

 

[ban-all-sheds]

The shower circuit in my house was straight forward but my brothers house isnt! Do i really have to explain my reasons for asking about something that im not 100% sure about?

No, but it might be interesting to see you explain how you knew you'd done your supplementary bonding according to the regulations when you don't know what the regulations are.

http://rapidshare.com/files/96697332/NL139supp.pdf

http://www.voltimum.co.uk/files/gb/attachments/niu/l/attachments/e169-9.pdf

Bonding & plastic pipes

But the more posts you make here the more it looks to me as if you are doing or about to start jobs for which you are not competent and for which you think you'll just ask whatever questions happen to occur to you as you go along, completely ignoring the potential for unknown unknowns, which I don't think is a good idea.

So I'll leave it to others to support you in this somewhat foolhardy approach....

 

[kwil69]

Not quite like that but I am learning as everyone does when they start out. Thanks for the links