secondary consumer unit and bonding

[neil_ev]

hi all

I have been asked to change a consumer unit in a house. Most of the house is covered by a new consumer unit (17th ed.) and all the bonding to gas and water is covered by this. The consumer unit i am changing covers the electrics in an old extension that consists of 2 bedrooms and a living room. The only circuits on it are 1 ring for sockets, 1 radial for sockets and a light circuit. My question is do i have to ensure that the gas and water bonding are covered by this CU also, or is the fact that it's got a 16mm main bond back to the MET enough?

thanks

neil

 

[Amp David]

No because they are already bonded to a MET,

 

[Taylortwocities]

How is the second CU (DB2) that you are replacing connected to the "juice".

Is it run from an MCB in the main consumer unit
or
Has it got its own set of tails from the incomer (eg henley block)
or
does it run from a separate switch fuse?

What type/size of cables connect to the main switch on DB2

 

[neil_ev]

it's got it's own set of 25mm tails coming from the main isolation switch by the meter. My thoughts were the same as Amp David, but just wanted to check.

 

[trev]

I would test potential ECPs mate just to make sure

 

[Plonker 3]

Unless the area covered by the separate DB has a different equipotential zone then no bonding needs to be run to the DB.