After a New Consumer Unit, now I need EICR & 100A DP Isolation Switch

[OLDBOY]

Not a main switch in a db, I use a separate RCD main switch which provides back up fault protection in case of rcbo failure, and protects the metal frame of the db rather than relying solely on mechanical protection to the tails.

 

[newfutile]

I guess your mean a s type (RCD) Residual Current Device in a tt system,otherwise there in no selectivity and little point in having rcbos,I have never had an rcbo fail only the rcds seem to fail for some strange reason

 

[mainline]

Not a main switch in a db, I use a separate RCD main switch which provides back up fault protection in case of rcbo failure, and protects the metal frame of the db rather than relying solely on mechanical protection to the tails.

If the db isn’t remote from the cut out and tails are properly installed a main switch with dp rcbos is compliant adding an upfront rcd is going to reduce selectivity

 

[OLDBOY]

If the db isn’t remote from the cut out and tails are properly installed a main switch with dp rcbos is compliant adding an upfront rcd is going to reduce selectivity

In that instance sp rcbo's would be compliant. I have never said otherwise, and I have always stated an s type rcd main switch which will give selectivity. But many, myself included prefer to have the added insurance of an up front(s type) rcd on a tt, and in that case dp rcbo's are required. I have never stated that is the only option.

 

[mainline]

Not a main switch in a db, I use a separate RCD main switch which provides back up fault protection in case of rcbo failure, and protects the metal frame of the db rather than relying solely on mechanical protection to the tails.

If the db isn’t remote from the cut out and are properly installed a main switch and dp rcbos is compliant

In that instance sp rcbo's would be compliant. I have never said otherwise, and I have always stated an s type rcd main switch which will give selectivity. But many, myself included prefer to have the added insurance of an up front(s type) rcd on a tt, and in that case dp rcbo's are required. I have never stated that is the only option.

sp rcbos on a tt with a main switch would have no selectivity with a N to E fault.

I think the issue is making a statement saying Required or Needed means that there are no other options.

 

[mainline]

edited double sent

 

[mainline]

In that instance sp rcbo's would be compliant. I have never said otherwise, and I have always stated an s type rcd main switch which will give selectivity. But many, myself included prefer to have the added insurance of an up front(s type) rcd on a tt, and in that case dp rcbo's are required. I have never stated that is the only option.

You just said it again “ dp rcbos are required”.

Dp rcbos are not a requirement they are an option.

 

[OLDBOY]

I think you are rather mis-interpreting. I have only ever stated that where an upstream s type rcd is used in front of a db with rcbo's single pole rcbo's would not be compliant and therefore by default are required in that situation.I stand by that.

 

[mainline]

I think you are rather mis-interpreting. I have only ever stated that where an upstream s type rcd is used in front of a db with rcbo's single pole rcbo's would not be compliant and therefore by default are required in that situation.I stand by that.

Look at the definition of Required.

Your post @ 34 says sp rcbo with main switch would be compliant?

 

[OLDBOY]

A main switch....not an rcd main switch. A db with a main switch and sp rcbo's would be compliant. It is not the way i would do it though.
Add a s type rcd main switch and the sp rcbo's are no longer compliant.