RCBO required?

[IAmSparkytus!]

Would you deem a socket (twin or commando) to be exempt from requiring RCD protection if it is fitted above a suspended ceiling installed to supply a specific piece of equipment?

Initially I'm thinking yes. Wouldn't think anyone is going to go out of their way to access them if there are other sockets dotted around at standard height.

Thoughts, please?

 

[loz2754]

The regulations (411.3.3) require an RCD for all socket outlets with a rated current not exceeding 32 amps, unless a documented risk assessment is carried out, explaining why an RCD is not required.
Except for a socket outlet in a domestic installation, which cannot be omitted for any reason.

 

[dodger421]

Would you deem a socket (twin or commando) to be exempt from requiring RCD protection if it is fitted above a suspended ceiling installed to supply a specific piece of equipment?

Initially I'm thinking yes. Wouldn't think anyone is going to go out of their way to access them if there are other sockets dotted around at standard height.

Thoughts, please?

If it’s non-domestic the yes, you can do a risk assessment and omit RCD’s if that determines one is not required. See 411.3.3.

If it’s domestic there is no exception unless the cables are surface mounted and visible along their length, and even then that has caveats.

 

[i=p/u]

Just use a spur and forget the thought

 

[IAmSparkytus!]

If it’s non-domestic the yes, you can do a risk assessment and omit RCD’s if that determines one is not required. See 411.3.3.

If it’s domestic there is no exception unless the cables are surface mounted and visible along their length, and even then that has caveats.

Yeah, I've never understood that as cables on show I prefer to provide with RCD protection just as a bit more protection incase they get damaged.

 

[IAmSparkytus!]

Just use a spur and forget the thought

No good for load when a commandos needed though unfortunately.

 

[dodger421]

Yeah, I've never understood that as cables on show I prefer to provide with RCD protection just as a bit more protection incase they get damaged.

Agreed, its a sentence in the OSG that doesn’t make much sense to me either.

The paragraph above it (3.6.1 (b)) and 411.3.3, are clear that RCD’s are required for sockets outlets. Then you‘re told (3.6.2.1) they’re not specifically required for surface mounted cables.

Like you I’d fit them anyway.

 

[Mike Johnson]

Life is too short, just fit one anyway.

 

[polaroid]

Why would you NOT want to fit a RCD?

 

[pc1966]

Why would you NOT want to fit a RCD?

• Critical loads that you don't want spurious trips on.
• Stuff with very high leakage current (e.g. supply to rack of computers where you want to be able to change the UPS without getting a sparky in).
• Stuff with nasty waveforms that might trip one (e.g. some older high-power welders).
• Where it is not really required for safety and would require a board change or other means to actually implement it.

Those are unusual cases, but they do exist outside of domestic situations.

Even for domestic, putting spoke alarms on a MCB would be preferable to a RCBO. Or on the lights circuit as then the loss of power is noticed if it trips one day due to external influences (e.g. lightning surges or other high dv/dt effects from faults).

 

[i=p/u]

For a fridge, is the example in beano.