consumer unit mcb values

[mrcrow]

i have moved into a 1988 2 bed bungalow, and the consumer unit has 4 mcb's for the house circuits

the values are...30-30-15-5 amps

i am going to find out which circuits are relevant for the 2-30's and assume the 15 is lighting
what could be on the 5 amp mcb

there is a socket in one of the kitchen wall units for the hob extractor?
there is a socket in one of the kitchen base units for the fridge?
there is a central heating gas boiler?

cheers
geof

 

[PBC_1966]

That's relatively few circuits for house built in 1988. Most likely the 5A is for lighting and the 15A for something like an immersion heater. The two 30A ways are likely either two ring final circuits for sockets, or one for a ring and one for a cooker. All depending upon what was fitted originally and what has been changed since, of course.

 

[mrcrow]

That's relatively few circuits for house built in 1988. Most likely the 5A is for lighting and the 15A for something like an immersion heater. The two 30A ways are likely either two ring final circuits for sockets, or one for a ring and one for a cooker. All depending upon what was fitted originally and what has been changed since, of course.

thanks..it is definately 27 years old they tell me but i can check this out in the deeds when i get them
there are signs of a new boiler being fitted as the flue for the old one is blanked of
both go through the roof...its a bungalow
i assumed the 30's were for ring mains
i can now check the lighting on that 5 mcb tomorrow...when its light
and i will also do a check on the ring mains
there is an electric shower in the newish bathroom..
the existing cooker is free standing and gas and looks as if its pretty old
if i find what is left still functioning that might be the 15
will check back tomorrow PBC and thanks again
geof

 

[JohnD]

although a 1980's house often had an upstairs ring and a downstairs ring, an upstairs lighting circuit and a downstairs lighting circuit, a 1980's bungalow is much more likely to have had one ring, one cooker radial, one lighting circuit, and one immersion heater.

As you now have an electric shower, the old cooker circuit may well have been repurposed for that.

If necessary, I would put 50p on it.

 

[PBC_1966]

there are signs of a new boiler being fitted as the flue for the old one is blanked of

If it's been fitted near where an old hot-water cylinder with electric immersion heater used to be, there's a chance the old 15A water heater circuit was reused for the boiler, but gas boilers don't draw a lot of electrical power, so it's quite normal for them to just be connected via plug & socket or FCU into circuits supplying sockets.

there is an electric shower in the newish bathroom..

Electrically heated, or just electric for a pump?

If the former, then one of the 30A ways might have been resused for the shower, which might be of concern given that the majority of newer instant electric showers draw more than 30A. Are you sure these four MCB's are the only ones feeding the whole house, and there isn't another unit added alongside? (Pictures would help.)

the existing cooker is free standing and gas and looks as if its pretty old
if i find what is left still functioning that might be the 15

Like gas boilers, the electrical requirements for a gas cooker are small (clock, lights, igniter) so it's quite likely the socket provided for it is on the ring.

 

[PBC_1966]

although a 1980's house often had an upstairs ring and a downstairs ring, an upstairs lighting circuit and a downstairs lighting circuit, a 1980's bungalow is much more likely to have had one ring, one cooker radial, one lighting circuit, and one immersion heater..

The late 1980's just seemed a little late to be skimping to that extent, but thinking about it being just a 2-bedroom bungalow and possibly wired on a tight budget, could be.

 

[mrcrow]

thanks chaps

there is another unit next to the house one and it serves the conservatory...i found this out when one of the lights in the conservatory went and lifted the RCD?...i changed the bulb and reset it and all was fine
there is one twin socket in the conservatory and two lamps

but i will get the photos tomorrow so you may see the situation

many thanks again
cheers
geof

 

[stillp]

My 1982 house only had 4 circuits, on a rewireable Wylex standard. That was a 4-bed detached.

 

[mrcrow]

ALL by mrcrow_uk, on Flickr

HOUSE by mrcrow_uk, on Flickr

CONSERVATORY by mrcrow_uk, on Flickr

SHOWER by mrcrow_uk, on Flickr


this is the layout of the electric units
the one marked conservatory is the one which the rcd went when one of the conservatory light bulbs blew...the house lights were ok
hope this helps...and i didnt look clearly at the start and see there is a unit for the shower
cheers
geof

 

[333rocky333]

I think they may be cartridge fuses rather than MCB's

 

[mrcrow]

I think they may be cartridge fuses rather than MCB's

are they easy to replace or do they work like mcb' and you reset them

 

[kai]

They look like cartridge fuse holders to me (on the Proteus unit), a format widely used in the Eighties.

 

[PBC_1966]

Well, obviously you now know that the shower had its own unit added with RCD & MCB. If the conservatory was added on sometime later, then that middle board for the addition makes sense. So the two 30A fuses on the main house board are then most likely either two rings, or ring and cooker.

 

[333rocky333]

Best with the main switch off to change them, you push the lever down gently, and will see the fuse in there, they are like plugtop fuses but different sizes per amperage, proberly not easy to get, proteus are made by CEF, but other s may fit, once hinged down the fuse pulls up and out, again refit only with main switch off, to prevent arcing/damage.
To be honest they rarely blow unless an extreme fault, once blown they need replacing with a new fuse, once removed they can be tested by a basic continuity test with a multimeter

 

[PBC_1966]

are they easy to replace or do they work like mcb' and you reset them

Replacement takes just a few seconds - Pull the carrier open, lift the old fuse out, drop a new one in, close the carrier.

The fuses are BS1361 types, like these:

https://www.tlc-direct.co.uk/Main_Index/Consumer_Units_Index/Wylex_Standard_Carriers/index.html