When do you NOT need a cpc?

[bengasman]

Interesting question came up in the heating section, which has a fairly obvious answer technically, but I have no idea what the legal answer is.

When does a (flex) cable not need a cpc?

This came up on a question asked about earthing a cylinder stat on a hot water cylinder.

 

[Spark123]

When the appliance is double insulated and if talking about a fixed installation, only when the installation is supervised.

 

[bengasman]

Cheers geez.

Dropped one here.
I actually meant: are there any exceptions apart from double insulated and lamp from ceiling rose?

 

[kevindgas]

bengas would you wire a lighting circuit without a CPC? no.
then why would you run 3 or 4 feet of cable round an airing cupboard without one? when it far more likely to be damaged! I personally would never run any cable carrying 240volts without a CPC/earth.

 

[londonboy]

The cylinder stat still needs an earth to protect the cable. Otherwise nothing will happen if someone damages the cable.

 

[RF Lighting]

That's not what the CPC is there for.

It is to prevent any metal work in the installation or appliance coming live under fault conditions. It is not there to protect against cable damage (except in SWA etc)

If the appliance is double insulated, then no CPC is needed, and it is a waste to provide one.

Fixed wiring should have a CPC to every point, even if it is supplying DI equipment.

 

[bengasman]

bengas would you wire a lighting circuit without a CPC? no.

No, I most certainly would not; in fact I am a coward and tend to overdo cable sizes and bonding and earthing

then why would you run 3 or 4 feet of cable round an airing cupboard without one? when it far more likely to be damaged! I personally would never run any cable carrying 240volts without a CPC/earth.

I would not.
Merely curious if there were any circumstances that would not require a cpc.
Though officially qualified as a sparky, there are a lot more things I don't know about electricity than about gas.

Both in gas and electric regs are plenty of things that are illogical, but nevertheless legal or illegal.

 

[kevindgas]

no problem with that mate, like you i tend to be over the top on stuff, but at least I know its not gonna bite me big time

 

[bengasman]

Exactly.

Unless the M.I. state otherwise, you are still allowed to have an electric shower without a rcd.
Never, ever would I use or install one without.

I started off in electrics/electronics with telecommunication when semiconductor uhf/shf amplifiers where very expensive so valves was the word.
2c39 was favourite. Google the specs, and you will understand where I got my respect for electricity.

 

[RF Lighting]

Unless the M.I. state otherwise, you are still allowed to have an electric shower without a rcd.

Not any more you're not

 

[bengasman]

Exactly.

Unless the M.I. state otherwise, you are still allowed to have an electric shower without a rcd.

And only since last year are you not allowed to install without.

I have never installed one without rcd, nor been willing to use one without.

Like I mentioned above, I am a coward. I don't fancy being electrocuted.
Had a shock from 700 volt and I can still remember it. Without affection.
And it was about 30 years ago.

Also seen an execution of a guy on the chair; he really did not seem to enjoy it.

 

[holmslaw]

..

 

[Spark123]

Something rattled your cage?

 

[bengasman]

Didn't know bambi lurks here too, somehow thought he was limited to p&h.
Shared sorrow is half sorrow I s'pose.

 

[holmslaw]

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