Shower install, old fuse box

[Aragorn84]

I'm looking at installing an electric shower in my house.

I've had a look at the fuse box tonight and its a very old thing (It looks a bit like a "memera 3" i found on google but has 6 fuses rather than 4) with replaceable fuse wire and 4 pin fuses. It currently has two 30A fuses (cooker and sockets) two 5A fuses (lights and boiler) and two 15A fuses (one for an outdoor light and the other for a electric fire in the livingroom)

My plan was to do away with one of the 15A fuses and run the outdoor light and the fire off the same fuse, then that opens up a spare fuseway to connect the shower to. My problem is ive not idea where i can find fuses for this old thing?

The property is rented, and i dont really fancy shelling out my own cash to upgrade to a nice modern CU for the landlords benefit as we probably wont be here much more than a year.

Any ideas or suggestions on what to do with it?

Thanks

Kevin

 

[streetlighter]

I dont think the landlord would be very happy about you doing alterations to the electrics in his property.
That fuseboard sounds quite old and will not be abe to cope with the increased load of an electric shower.
Did you get an electrical cirtificate for the property when you moved in ?

The best way to supply the shower would be to install a small consumer unit with an RCD main switch and suitable MCB for the load, This work should be done by a qualified electrician.

 

[Aragorn84]

http://i167.photobucket.com/albums/u125/mdbalson/P3160021.jpg

Thats what the fuse box looks like, but its a little wider, and has 6 fuseways

I'd have to check the paperwork, but i dont think we did get any form of electrical certificate when we moved in here.

I would also point out that the work would be done with the landlords permission, although it would be paid for by myself hence not wanting to replace the entire unit! At the end of the day the landlords quite happy about a free upgrade to his property, ie the addition of a shower, however he isnt wanting to shell out for it.

 

[sparkyspike]

I'd take streetlighter's advice and install a proper dedicated shower CU with RCD and get an electrician to fit it. They're not too expensive. It depends how much you want a shower! Would it be worth persuading your landlord to have a new CU fitted? It would certainly be in his interest to have an upgrade done. Perhaps if you were to offer him the cost of just upgrading the shower circuit against the cost of a complete CU, he could be tempted. An electrician can quote for both and you can compare the difference.

 

[Vicario]

My sparkie charged £165 for a 63A Niglon mini shower unit which has a RCD incorporated. This included fitting. Have you checked that your cable and main fuse are up to such a powerful upgrade?

 

[Aragorn84]

I've spoken to him previously regarding it and he basically said he simply cant afford the additional cost of installing a shower, but that if i want to do it i can.

What should i be checking on the CU to see if it has enough capacity to run this additional load? The Current rating of its main switch? Or the rating of the service fuse? I seem to recall the service fuse having 60/80A stamped on it, but i dunno how it can have two ratings? Unless that means the carrier can take either and i'd have to pull it to see whats actually installed?

If i were to install a seperate CU for the shower i'd need to tap into the meter tails going to the existing CU..

Would something like:

http://www.screwfix.com/prods/30959/Electrical/Consumer-Units/Volex-Consumer-Units/Shower-Unit

as an additional CU and:

http://www.screwfix.com/prods/11497...umer-Units/3W-100A-SP-Service-Connector-Block

to split the existing meter tails into both CU's do the job?

The other option of replacing the entire CU might be possible, if it was cheap enough.

http://www.screwfix.com/prods/94258.../Wylex-9W-Split-Load-CSU-Complete-With-5-MCBs

Would something like that be sufficient? I notice it has a 100A main switch, if the service fuse is only 80A is this a problem?

Is there any LEGAL requirement to have a spark do this work? I feel perfectly confident doing the work myself once i've figured out the best approach, the only part that i think might be iffy in terms of legality is the splitting of the meter tails/installing the meter tails to the new CU. I guess officially i would need to get the power company out to remove the service fuse and make the hookup, but would a sparky really do that? Or just pull the fuse and get on with it?

Cheers

Kevin

 

[davelx]

I suggest you read this - carefully:

//www.diynot.com/wiki/electrics:part_p:diy_electrical_work_and_the_law

Your landlord should be insisting that you provide a correctly completed EIC and Building Regulations Completion certificate from the local authority or Part P Scheme provider. Do you have the correct test equipment to be able to complete the EIC? Do you know how to use it?

 

[Aragorn84]

I dont think Part P applies to me as i'm in scotland?

From what i can gather from reading that anyway, it seems that should be able to DIY it as long as i notify building control then get the LABC people to certify the work?

 

[davelx]

Ah, sorry, missed that - not had my first coffee yet

You should probably check with your local authority on what is required.

However, the comments about EIC and test equipment still stand if (as he should) the landlord expects the work to be done in compliance with the wiring regs.

 

[Aragorn84]

Well no, i dont have any test equipment. Could you please advise on what actually needs tested?

I think the 9w consumer unit linked to above will likely be the best way to go about the installation, however will that then mean i need to have the entire property tested? Or just the hookups to the CU and the new shower circuit?

I suspect the meter tails may only be 16mm... Is this a problem with having the 100A main switch on the above CU?

 

[davelx]

Well no, i dont have any test equipment. Could you please advise on what actually needs tested?

http://www.tlc-direct.co.uk/Book/8.1.1.htm

Enjoy!

 

[Aragorn84]

Well due to the lack of suitable equipment it would seem that i couldnt actually do any of that testing myself... Nor could i sign off the certificates as it appears they need signed off by a "qualified" person....

Seen as this is a DIY website, what would you suggest the best approach here would be? Do i replace the consumer unit and hook up the shower myself then get a spark in to do the testing and knock up a certificate?

Simply phoning up an electrician and shovelling cash at him to do the whole job is something i simply cant afford to do, hence asking the questions on here!

 

[ban-all-sheds]

I dont think Part P applies to me as i'm in scotland?

It doesn't, but there is legislation which does - there are Scottish Building Regulations, and there are warrants, and property type affects things, so you need to check it out.

Seen as this is a DIY website, what would you suggest the best approach here would be? Do i replace the consumer unit and hook up the shower myself then get a spark in to do the testing and knock up a certificate?

Replacing a CU is a very non-trivial task, and nobody with any sense would do it without carrying out certain tests on the existing installation first. And you've got the problem of isolating the supply and ensuring that your new design complies with the latest version of the Wiring Regulations.

Also you will really struggle to find an electrician prepared to do the testing and "knock up a certificate" after the event.

You need to decide what you want to do, you need confirmation in writing from the landlord about certification (I'd be surprised if his insurance allowed just anybody to do electrical work) and you need to involve your electrician right from the start to discuss how much of the donkey work you can do to save money.

 

[Aragorn84]

As far as i'm concerned, physically replacing the CU itself isnt complicated, the circuits are already in place and all your doing is labelling and disconnecting them from one unit, and then screwing them into the new unit in their respective places. Isolating the Mains might be an issue, but then i suspect a spark would probably just pull the service fuse anyway.

The testing is a problem as i dont have this equipment.

What tests should be conducted on the existing installation?

The wiring is clearly old, would it be likely that changing the CU would result in the entire house being rewired due to the old wiring not meeting the current version of the regulations?

 

[ban-all-sheds]

As far as i'm concerned, physically replacing the CU itself isnt complicated, the circuits are already in place and all your doing is labelling and disconnecting them from one unit, and then screwing them into the new unit in their respective places.

What will your design for the separation of RCD sections or use of RCBOs be to achieve compliance with Regulation Group 314?

How will you know that you'll be complying with 131.8?

How will you know that the Zs for each circuit will be OK? If any are wrong now that doesn't mean that you can just replace the CU and leave them wrong.

Ditto the current-carrying capacity of the cables.

How will you know that your voltage drops will comply with the revised requirements?

Physically connecting cables is not the issue, and is irrelevant - there's a lot more to it than that.

Isolating the Mains might be an issue, but then i suspect a spark would probably just pull the service fuse anyway.

He might.

It's illegal, but he might.

The testing is a problem as i dont have this equipment.

Then you can't properly replace the CU.

What tests should be conducted on the existing installation?

• Continuity of cpcs
• Continuity of ring final conductors
• Continuity of main and supplementary bonding conductors
• Insulation resistance
• Polarity
• Earth rod resistance if you have a TT supply

Plus you should inspect the routing of cables to determine if they need insulation or grouping factors applied to them.

The wiring is clearly old, would it be likely that changing the CU would result in the entire house being rewired due to the old wiring not meeting the current version of the regulations?

Possibly, but if that was needed it would be because the non-compliances were genuinely dangerous, not just technical breaches.