RCD or earth bonding?

[mrlennie]

Hi guys just a general thought -

Been reading if your house is protected by an RCD you don't need earth bonding.

Now I have read that your whole house shouldn't be fully protected as you could be left without power if a fault occurs say in the sockets but you wouldn't have lighting zilch so for this reason it goes against the newest electrical regs...

What do you think?

 

[dontknowitall]

I'm don't know too much about this but the lighting circuit is on a different part of the consumer unit so is not affected the same way. Also I think the trip out is longer than nanoseconds. Not sure if this is of any help.

 

[oldplumber]

from ltd knowledge all circuits are now rcd /rccb protected on an individual basis or on a large rcd for sockets cts. Still need bonding to allow for earth leakage detection in first place depending on protection device being used. However ed 17 regs have changed a fair bit to make things safer so only real answer is to check with your sparky.

 

[Bernie2]

As far as I know, they reckon a house should still be earth bonded, as RCD's rely on mechanical means to shut off the power and putting it simply mechanical means can fail or lock up.

RCD's fitted of course make a system a lot safer and the new regs ask for more of them to be used.

The split unit idea is to keep a light on if the RCD trips.

Apparently it is thought dangerous if lighting circuities on a single consumer unit with a whole house RCD tripped and put all the lights out as well. So they split the units.

The problem with RCD's on the consumer unit, is that if one socket causes a trip then usually all the power circuits go off. Now if you have got a freezer full of food on a circuit that may have nothing to do with the reason the trip occurred your not going to be to happy are you?

So I think the new regs are about using more RCDs so you can even use them on individual sockets.

Also they are also revising the trip times as some appliance motors can cause them to trip when they start up.

In point this is only some of the thinking behind the new regs and certainly not a full explanation, in fact its all a bit rushed, but you can get the information more fully from one or two other sites.

I find regs easier to understand if I know why they are being introduced in the first place, rather than learn the letter and name of this or that reg and what it says without knowing why its being asked to be followed.

 

[ddplumbing]

Had this discussion with my sparky last month, he says his regs now state, if its a 17th edition consumer unit with split rcd's then he isnt required to earth bond any more.

Apparantly this has come about due to the increased use of plastic in systems which break up the copper continuity, if not the water continuity!