DB installed connected & tested

[cliffed]

@Leesparkykent its a time delayed one so "should" be ok, you can just see the S on the front of it.... The rcbos are only single pole though so there still isnt perfect discrimination and a fault remaining on the neutral will trip the whole supply... Not a great setup imo...

Agree,could be a problem there

 

[MFS Electrical]

My issue with the Lewden boards is the advised torque settings, I have two torque drivers and with either if I torque them to manufacturers settings it has a tendency to damage the rcbo screws.

Do you have the pozi-flat hybrid type driver in your torque set? I do and have never had an issue with the Lewden RCBOs

 

[Deleted member 26818]

Think I would have kept the main switch and installed a 63A RCBO, rather than swapping the main switch for an RCD and using a 63A MCB.

 

[cliffed]

Yea,the problem is that the 63 amp breaker supplies a Loxone lighting panel,Rcbos in that Panel serves lighting .
So that was the purpose for the 100 ma td Rcd,discrimination for the other rcbos.

 

[suffolkspark]

Trouble is unless they are double pole rcbos then you have provided no discrimination.....

 

[Andy78]

How is fault protection provided for the 63A circuit ?

 

[suffolkspark]

How is fault protection provided for the 63A circuit ?

By the upfront rcd....

 

[Andy78]

By the upfront rcd....

I thought it was time delayed ? How will this meet disconnection times ?
Bear with me as I have nothing to do with TT systems and probably lack a lot of knowledge in this area.

 

[Wilko]

I thought it was time delayed ? How will this meet disconnection times ?
Bear with me as I have nothing to do with TT systems and probably lack a lot of knowledge in this area.

Hi - TT disconnection times for a distribution circuit is up to 1 second from Reg 411.3.2.4

 

[Andy78]

Hi - TT disconnection times for a distribution circuit is up to 1 second from Reg 411.3.2.4

Cheers for that. Thought I would be missing something. Didn't think the higher times applied to TT.
Every day's a school day.

 

[Deleted member 26818]

5s for non TT.

 

[cliffed]

This came with the rcb’os,providing a upfront Rcd is used,it’s ok-ish,I realise discriminating may not be ideal,but what else can you do,on a TT system.

 

[cliffed]

This came with the rcb’os,providing a upfront Rcd is used,it’s ok-ish,I realise discriminating may not be ideal,but what else can you do,on a TT system.

Trouble is unless they are double pole rcbos then you have provided no discrimination.....

yea,your talking about the N/E faults that may happen,discrimination will occur when there’s a L/E fault.
Who on earth uses double pole rcbo’s,.

 

[cliffed]

Notsure if this uploaded,this came with the rcbo’s

 

[suffolkspark]

But N/E faults are mighty common? Meaning that one ANYWHERE on that install will cause the upfront to trip loosing the entire installation.

imo that doesnt comply with the regs so either DP rcbos or an alternative design should have been considered.

Also imo on TT with a full rcbo board the 100ma S is not required upfront so youd actually be better off swapping that mcb for an rcbo and the upfronter to a main switch...

 

[cliffed]

Ok,but then neutral to earth faults will not be disconnected at all,they will remain,unless DP rcbo’s are used.
The reasoning for the time delay is,discrimination for the lighting panel,which have its own rcbo’s.

 

[suffolkspark]

But there is no discrimination because it will trip on a N - E fault?

 

[cliffed]

A neutral fault on that circuit,will trip the individual rcbo’s on the lighting panel,before tripping the time delay Rcd.

 

[cliffed]

Something I’ve read:

 

[suffolkspark]

Are you an electrician?