What type of system is this?

[DangerToDIY]

Hi Please take a look at this

Can anyone tell from the picture what type of earthing system this is?

Can anyone recommend a good consumer unit for whatever type of system this is?

Any help would be much appreciated.[/img]

 

[ban-all-sheds]

Can't see the arrangement clearly enough - where do those perforated metal straps go?

 

[Lectrician]

I place my bet at TN-S. But require a photo of the service head more than the fuse board.

I would consult the rec with ref to the old service head. It maybe in need of replacemet.

 

[plugwash]

do you get your electricity bills direct from an electricity supply company (as apposed to say a landlord)
the following assumes this is the case if not post back

it looks like
TN-S with the earth delivered to the CU through the joint to that other metal box

there don't seem to be any single earth wires into the CU

this is bloody dodgy especially given the corrosion state

and that B40 fitted without a base is really dodgy (i would make an educated guess that the CU has a 63A main switch in which case it shouldn't have such a large breaker anyway)

i would advise the following

fit a new split load CU above the existing one
move the cuircuits to it and put EVERYTHING on the rcd side for the moment
connect 10mm earth cables from it to the incoming water and gas
connect it temporerally to the B40 in the existing CU with 6mm twin and earth
get some red and black 25mm tails and some 16mm single earth ready

find out who the distribution network operator is for your area
ring them and tell them you suspect your property has no earth (there is frankly a pretty good chance it does not) and it should get a fast response

while you have them there you can take the temporary 6mm cable out of your new CU attach the 25mm tails and 16mm earth to it and ask them to connect those inseatead of the old CU

 

[algenon_iii]

I'd get onto SWALEC as soon as you I were you, the number was (and probably still is) 0800 052 5252

 

[securespark]

Ban the earth straps link each incoming cable then terminate on the incomer housing, from which stranded unsheathed wires run to the CU.

Seen this type once before. Recommended a new intake, meter and CU, as they were all inadequate for the additional loads intended to be supplied - ie new shower 9.6kW.

Certainly your existing CU is old Wylex and not able to take the 40A load - no Wylex CU with a main switch less than 100A should take a circuit greater than 32A. (Any Wylex board that does not say 100A main switch on the front has not got a 100A main switch). Plus, any CU whatever the age or make is not designed to take more than one 40A breaker.

Also, the reason the guy left the shield off is probably because it is designed NOT to fit any unsuitable Wylex board, so instead of taking the hint, he just left it off altogether. Naughty, naughty, very naughty.

 

[ban-all-sheds]

there don't seem to be any single earth wires into the CU

I think that this is it/them:

 

[plugwash]

[quote="securespark"
Seen this type once before. Recommended a new intake, meter and CU, as they were all inadequate for the additional loads intended to be supplied - ie new shower 9.6kW.
[/quote]

agree totally which is why i reccomended temporary connection of the new CU via the old one and then getting the rec out to clear up their mess at the incomer and connect the new CU directly while they are at it

 

[DangerToDIY]

Hi guys thanks for all of the help so far.

ban - That strap does connect to the box that the fuses are in from the two incoming thick wires at the bottom.

I will phone swalec asap. Some of the insulation has started to melt to gether on the neutral terminal strip too which is quite worrying.

Plugwash- We get our bills direct from virgin energy as we own our house. I've got to pick up a twelve way split load mk sentry cu on monday. I will get the tails and earth while I'm at it. At the moment we have one ring that serves the whole house for mains. One circuit for the whole house for lights, one for water heater and one for the cooker. I plan on splitting the ring so we have one downstairs and one upstairs and same for the lights. What size and type of mcb's should i buy for each circuit? Which rcds should i buy?

Also our light circuit only has red and black wires! No earth it seems on those, so am i right in saying i should get some 1.5mm twin and earth to rewire those?

 

[Lectrician]

Thats a house install !?!?!

Steel conduit, and an incomer like that !!!!

 

[plugwash]

I plan on splitting the ring so we have one downstairs and one upstairs and same for the lights. What size and type of mcb's should i buy for each circuit? Which rcds should i buy?

the split load board will come with a suitable RCD

you need MCBs of suitable ratings for the cuircuits you are installing
6A-lights
32A-ring
that cooker cuircuit looks like 6mm cable to me so it should be ok to replace it with another 40A breaker
the water heater should be placed on a 16A breaker

i would put everything on the RCD side of the CU until you get the earthing and supply wiring properly sorted at which point you should move lights to the non rcd side

Also our light circuit only has red and black wires! No earth it seems on those, so am i right in saying i should get some 1.5mm twin and earth to rewire those?

yes thats what you should do

 

[securespark]

Looking again at the piccy, there is only one neutral to the meter, the outgoing live is pvc DI, but both tails incoming to CU look like fabric covered VIR.

Also, shower T & E looks a bit thin and is run in tight conduit.....

Be afraid! Be very afraid!

 

[DangerToDIY]

Also, shower T & E looks a bit thin and is run in tight conduit.....

we dont have a shower yet as I was too scared to connect anything to this setup. The thick wire in there is 6mm t+e for the cooker.

 

[ban-all-sheds]

6mm in conduit on a 40A breaker. More naughtiness.

 

[securespark]

That's what I was getting at PPman...(!)

6mm T & E in what looks like 20mm conduit. Tight fit, man....