Different types of DNO domestic main fuses / switches

[Sampdoria]

Hi

I came across a house yesterday that had a very old looking main switch (a old rusty box with a large metal handle on the right hand side). I've been told various stuff about these, including that they should be taken out by the electrical supplier ASAP, but i'm not certain what to believe!

Anyone know what these are? What type of fuse it would normally contain? Plus should they actually be removed?

I'm used to seeing the 1361 but i wasn't sure what this medieval thing was i was seeing!!!!

Thanks in advance

Samps

 

[fido]

Very old fuse boxes tended not to have a built in isolating switch but had a separate one such as you describe. when replacing such a fusebox with a new CU you would normally do away with the old switch as well.

 

[Sampdoria]

Very old fuse boxes tended not to have a built in isolating switch but had a separate one such as you describe. when replacing such a fusebox with a new CU you would normally do away with the old switch as well.

Yeah i've seen that arrangement before, this one though is the actual service head rather than an isolator. Thanks for the reply though.

 

[DESL]

A picture speaks a thousand words - have you got one?

 

[Sampdoria]

A picture speaks a thousand words - have you got one?

indeed i have!!!

not the best quality, but hopefully you'll see what i'm talking about.

Tails go from the incomer to the meter and then onto the CU with no further isolator. The main earth is connected the metal surround of the box.

http://i173.photobucket.com/albums/w64/sampdoria_photo/07022007.jpg

Am i right in assuming its TN-S ?

 

[sparkybird]

Can you open up the main switch box? In you will probably find ceramic fuses. If the neutral is fused, then this must be changed over by the DNO as it is no longer legal. Often though you find that the neutral conductors just 'run though' the fuse gap.

SB

 

[bernardgreen]

Can you open up the main switch box? In you will probably find ceramic fuses. If the neutral is fused, then this must be changed over by the DNO as it is no longer legal. Often though you find that the neutral conductors just 'run though' the fuse gap.

SB

IS THAT WISE

If the box is corroded there is no telling what state it is inside. It may fall apart if the hinges are jammed or the switch mechanism which has to be in the OFF position before the box can be opened may fall apart inside when disturbed.

 

[john-boy]

Hi sparkybird,
i know this is nothing to do with the current topic, but i have been reading a previous thread & am very interested to learn from you how you got part p certification. I want to become a qualified electrician, and have completed the c&g 2351. What did you have to do to prove competency? Am finding it hard to get on as firms only want to recruit apprentices or experienced & time served sparkys. Do you know if this is a way of moving towards obtaining nvq level 3 to become a qualified sparky?

thanks for your help. If your reply is as long winded as my question I'll give you my email address.

thanks,

john

 

[fido]

Surely if this switch is before the meter it should be left to the electricity supplier to remove it. In the meantime it is a handy means of isolating the supply if you are fitting a new CU.

 

[JohnD]

Surely if this switch is before the meter it should be left to the electricity supplier to remove it. In the meantime it is a handy means of isolating the supply if you are fitting a new CU.

I wouldn't call it "handy," I'd call it "likely to fall apart if you touch it."

 

[securespark]

Strangely, I find myself agreeing with John once more (isn't that annoying? ).

I would get the DNO to check it out. In my experience, they would fit a new cut-out.

 

[Sampdoria]

Strangely, I find myself agreeing with John once more (isn't that annoying? ).

I would get the DNO to check it out. In my experience, they would fit a new cut-out.

Fair enough!!!!