BS7671:2018 Proposed Changes

[davesparks]

Cooker circuit, electric heaters, distribution circuits to outbuildings, boilers ........

I reckon if you tried you could easily design a domestic install without a single RCD in the CU.

i think you'd still end up putting thbathroom lights on an rcbo, but apart from that you can do it with RCD sockets everywhere and steel conduit in all the chases.

 

[Ian1981]

i think you'd still end up putting thbathroom lights on an rcbo, but apart from that you can do it with RCD sockets everywhere and steel conduit in all the chases.

Plastic trunking for drops and light switches on pull switches.........
Proper rough!

 

[Flanders]

Cooker circuit, electric heaters, distribution circuits to outbuildings, boilers ........

I reckon if you tried you could easily design a domestic install without a single RCD in the CU.

I was just sugesting circuit that I could get away without the use of metal conduit , ie high level mounted spurs but , not sure how you would omit rcd protection in a bathroom , although you could have a frosted glass wall with the lights outside tbe bathroom

But as i mentioned the 18th addition with stop that with all lights requiring rcd protection

 

[Andy78]

i think you'd still end up putting thbathroom lights on an rcbo, but apart from that you can do it with RCD sockets everywhere and steel conduit in all the chases.

How each circuit in the bathroom has to be rcd protected

RCD remote from the CU or SELV.
Never said it was practical or desirable, just possible if you felt like an exercise in being awkward.

 

[bigspark17]

i think you'd still end up putting thbathroom lights on an rcbo, but apart from that you can do it with RCD sockets everywhere and steel conduit in all the chases.

18th will require any luminaire circuit to have rcd protection.
Afdd look good but the word "may be used" will mean people will not use them.

 

[Andy78]

Okay so apologies for derailing this one slightly, lets get back on track.

New reg 521.10.202 suggests that all wiring systems shall be supported so that they will not be liable to premature collapse in the event of a fire.
This replaces the old requirements for escape routes only.

Does this mean an end to clipped direct with PVC clips and plastic conduit saddles ? Buckle clips or similar and metal saddles are the obvious solution here, but does anything exist as a retro fit to existing containment systems like dado and perimeter trunking to meet this requirement ?
What about plastic SWA cleats ?

 

[davesparks]

18th will require any luminaire circuit to have rcd protection.
Afdd look good but the word "may be used" will mean people will not use them.

In what way do AFDD's look good?
Just look at the trouble they've caused in the USA where they are mandatory.
There is no practical way to test them, no way to know what has caused them to trip. And they suffer from massive nuisance tripping because the operate when they detect an arc, such as the arc that occurs in any switch or thermostat when you operate it,

 

[Gavin John Hyde]

Okay so apologies for derailing this one slightly, lets get back on track.

New reg 521.10.202 suggests that all wiring systems shall be supported so that they will not be liable to premature collapse in the event of a fire.
This replaces the old requirements for escape routes only.

Does this mean an end to clipped direct with PVC clips and plastic conduit saddles ? Buckle clips or similar and metal saddles are the obvious solution here, but does anything exist as a retro fit to existing containment systems like dado and perimeter trunking to meet this requirement ?
What about plastic SWA cleats ?

In terms of protection from fire, i have come across flame retardant clips and plastic saddles that withstand fire/heat upto a certain temperature. This was whilst working in a firework factory store room. where the fire precautions were obviously very OTT. the saddles were made of a composite material similar to kevlar. I can't be sure what the standard type of cable clips were made of but they were supplied by the design specification team and ready for when we got on the job. Surely something along these lines could be used retrospectively?

 

[Rpa07]

In terms of protection from fire, i have come across flame retardant clips and plastic saddles that withstand fire/heat upto a certain temperature. This was whilst working in a firework factory store room. where the fire precautions were obviously very OTT. the saddles were made of a composite material similar to kevlar. I can't be sure what the standard type of cable clips were made of but they were supplied by the design specification team and ready for when we got on the job. Surely something along these lines could be used retrospectively?

OBviously not in that Chinese factory that blew a couple of years ago. Watching the footage of the second explosion and the air movement a couple of miles away at the car park barrier was epic.

 

[Rpa07]

Try this - epic

 

[Pete999]

In terms of protection from fire, i have come across flame retardant clips and plastic saddles that withstand fire/heat upto a certain temperature. This was whilst working in a firework factory store room. where the fire precautions were obviously very OTT. the saddles were made of a composite material similar to kevlar. I can't be sure what the standard type of cable clips were made of but they were supplied by the design specification team and ready for when we got on the job. Surely something along these lines could be used retrospectively?

Just another thing to make the job more expensive.

 

[davesparks]

Just another thing to make the job more expensive.

No, it's another thing to prevent the loss of human life.
Firefighters have died from being trapped in cables which were not supported with fireproof fixings.

 

[Rpa07]

According to tony and Darren, most fires are caused by arc faults in high resistant joints so if we fit AFDDs everywhere we shouldn't have to fit metal retainers!
Only joking @davesparks before you berate me!

 

[Anthony S]

No, it's another thing to prevent the loss of human life.
Firefighters have died from being trapped in cables which were not supported with fireproof fixings.

Exactly, pf200 enclosed in surface pvc trunking in stairwells across the bulkhead areas (in tower blocks) for smokes, call points, sounders.

 

[Gavin John Hyde]

OBviously not in that Chinese factory that blew a couple of years ago. Watching the footage of the second explosion and the air movement a couple of miles away at the car park barrier was epic.

That huge explosion and fire in 2005 at Buncefield was much bigger and quite spectacular. supposedly biggest explosion since WW2. i was living in Amersham at the time and it woke me up. I dont think fire rated clips and saddles would have made much difference, neither would AFDD's.