Rcbos in commercial installations

[dokkan1080]

Just a quick question

Do rcbos need to be used on lighting circuits in a commercial setting?

Eg on a new build school/hospital/what ever

Or on a new circuit install on a school/hospital/ what ever commercial building?

 

[davesparks]

RCD protection is not required specifically because it is a lighting circuit, but may be required for lighting circuits for a number of other reasons.

You need to check the requirements for RCD protection in BS7671 to establish whether it is required for the particular circuits you are working on.

For example:

If the circuit is in a special location RCD protection may be required.
If the circuit includes cables buried in walls which don't meet any of the exceptions then RCD protection is required.
If it is a TT supply or has high EFLI then an RCD may be required for fault protection.

 

[dokkan1080]

Ah what if its existing? But complied when it was installed but not now?

Like lighting in a special location for example a swimming pool?

 

[davesparks]

Ah what if its existing? But complied when it was installed but not now?

Like lighting in a special location for example a swimming pool?

What do you mean, what if its existing? From what point of view are you asking?
Are you carrying out an EICR, are you working on another part of the installation, are you just a casual observer?

What exactly do you want to know here?

If you are carrying out an EICR then you do so to the current regulations, it doesn't matter whether it complied at the time of installation, you report on the installation as it is now and in accordance with the regulations which are in force now.

 

[dokkan1080]

What do you mean, what if its existing? From what point of view are you asking?
Are you carrying out an EICR, are you working on another part of the installation, are you just a casual observer?

What exactly do you want to know here?

If you are carrying out an EICR then you do so to the current regulations, it doesn't matter whether it complied at the time of installation, you report on the installation as it is now and in accordance with the regulations which are in force now.

A causel observer but a curious one wanting to learn...

On the ecir, an installation that was once deemed safe can be deemed unsafe once the regulations change?

 

[davesparks]

On the ecir, an installation that was once deemed safe can be deemed unsafe once the regulations change?

If that change in the regulations has happened because something was found to be unsafe yes in theory that could happen. In reality it is rare for a change in the regulations to be so major as that.

Generally things which complied with the last few editions of the regulations at the time of installation will not be deemed unsafe now, but they may be items which are recommended for improvement.

 

[dokkan1080]

If that change in the regulations has happened because something was found to be unsafe yes in theory that could happen. In reality it is rare for a change in the regulations to be so major as that.

Generally things which complied with the last few editions of the regulations at the time of installation will not be deemed unsafe now, but they may be items which are recommended for improvement.

Ah okay

So for example:

Circuit's in bathrooms and swimming pools ( I think) now need rcd protection that would be a fail on an ecir now even if it complied before?

 

[davesparks]

Ah okay

So for example:

Circuit's in bathrooms and swimming pools ( I think) now need rcd protection that would be a fail on an ecir now even if it complied before?

No, EICRs don't have pass or fail results, they give an overall assessment of the installation which can be satisfactory or unsatisfactory.

Also they give a list of observations about the installation which is a list of items which do not comply, these are coded C1 if they are immediately dangerous, C2 if they are potentially dangerous, C3 if they are recommended for improvement, FI if further investigation is required.

If any observations are recorded with a C1 or C2 code then the overall assessment must be unsatisfactory. If an any observations are given an FI code then usually this will result in an unsatisfactory overall assessment.
Generally if only C3 observations are recorded the overall assessment will be satisfactory. If no observations are recorded then the overall assessment will be satisfactory.

A lack of RCD protection is usually given a C3 code in most cases, though in some cases can be a C2 item.

 

[dokkan1080]

No, EICRs don't have pass or fail results, they give an overall assessment of the installation which can be satisfactory or unsatisfactory.

Also they give a list of observations about the installation which is a list of items which do not comply, these are coded C1 if they are immediately dangerous, C2 if they are potentially dangerous, C3 if they are recommended for improvement, FI if further investigation is required.

If any observations are recorded with a C1 or C2 code then the overall assessment must be unsatisfactory. If an any observations are given an FI code then usually this will result in an unsatisfactory overall assessment.
Generally if only C3 observations are recorded the overall assessment will be satisfactory. If no observations are recorded then the overall assessment will be satisfactory.

A lack of RCD protection is usually given a C3 code in most cases, though in some cases can be a C2 item.

Ahh thank you for that its makes a good amount of sense,

Going back to the ecir question how comes I read alot here that : the regs aren't retrospective? If even older works need to comply on an ecir

 

[davesparks]

Ahh thank you for that its makes a good amount of sense,

Going back to the ecir question how comes I read alot here that : the regs aren't retrospective? If even older works need to comply on an ecir

The regs aren't retrospective, you don't have to go back and change your past work every time the rules change.
Older works don't need to comply on an EICR, it is only items which affect safety which can be coded.

My usual example is the old wiring colours, red, yellow, blue phases and black neutral. This does not comply with the current version of BS7671, however it does not affect safety, the insulation works just as well whatever colour it is, so it should not be coded on an EICR.

But then many years ago the regulations required that the neutral of single phase circuits have a fuse in it, these days that is considered potentially dangerous and would warrant a C2 code.

 

[dokkan1080]

The regs aren't retrospective, you don't have to go back and change your past work every time the rules change.
Older works don't need to comply on an EICR, it is only items which affect safety which can be coded.

My usual example is the old wiring colours, red, yellow, blue phases and black neutral. This does not comply with the current version of BS7671, however it does not affect safety, the insulation works just as well whatever colour it is, so it should not be coded on an EICR.

But then many years ago the regulations required that the neutral of single phase circuits have a fuse in it, these days that is considered potentially dangerous and would warrant a C2 code.

Oh thats makes alot more sense I get it now.

So on an ecir for a bathroom or swiming pool circuits that pass through these locations now require rcd protection....

How would you know if that was needed to be coded either a c1 c2 or c3

Would it be considered dangerous or would if be a c3 how would you know ?

 

[davesparks]

Oh thats makes alot more sense I get it now.

So on an ecir for a bathroom or swiming pool circuits that pass through these locations now require rcd protection....

How would you know if that was needed to be coded either a c1 c2 or c3

Would it be considered dangerous or would if be a c3 how would you know ?

It isn't C1 as it isn't immediately dangerous, that is pretty much only ever going to be live parts exposed to touch or something which is actually on fire at the time of being inspected.

It is C2 if it is potentially dangerous, so if it would become dangerous if a fault occurs.

Otherwise if it is a recommendation which could improve safety then it is a C3.

You need to use experience, knowledge of the regulations and knowledge of the science of electricty to decide what code to apply to observations on a case by case basis.
Some things can be coded according to a generalised rule, but others have to be judged case by case.

For the bathroom situation it depends on other factors, such as whether it is in the zones or not and whether supplementary bonding is in place and correct or not. It could be either C3 or C2.

Swimming pools I have no idea about as I don't work on them.