TT & Amd 3

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soulman

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Hi,

I have watched the wylex Amd 3 video.  On TT systems they have a upstream REC2 enclosure with a 100ma S type RCD.  I have spoken to the tech helpline & they say it cannot be used as the enclosure is plastic.  This would really be ideal for TT systems, what your thoughts.

Cheers

 
I'd imagine that the tech help line are correct as the reg is for consumer units and similar switch gear..

The only real way to comply would be to gland the tails into the CU and have a 'S' type as the main switch

although if the REC2 enclosure is inside a non flammable enclosure then it'd be OK

 
Thanks Noz,

I would prefer it before the metal enclosure.  I don't think, with regards to TT this amendment hasn't been thought out.

 
Ah, I have the solution,

If a REC2 has been fitted, get a 100mA TD in a metal enclosure, slot the incoming side of the enclosure to suit the outgoing side of the REC2, butt it tight up to the REC2,  

does rhat make sense to anyone but me,? 

 
Why should a Rec2 with just an RCCB in it come under the metal reg?

The reg is for consumer units or "similar switchgear assemblies", assemblies meaning combinations of separate items eg DP switch and fuse.

Same with an RCD added to a circuit outside a CU. It can go in a plastic enclosure.

 
I was reading a document somewhere about this the other day. What they are recommending as a solaution was to use a metal CU, but with the meter tails suitable protected as it enters with a gland or egde protection strip, BUT with an RCD that has cable clamp for the tails, so you can't tug them out. Now I've never seen an RCd with a cable clamp.....

 
I think it says if it comes with a lid it needs to be NC.  If no lid is there it still complies.

 
I was reading a document somewhere about this the other day. What they are recommending as a solaution was to use a metal CU, but with the meter tails suitable protected as it enters with a gland or egde protection strip, BUT with an RCD that has cable clamp for the tails, so you can't tug them out. Now I've never seen an RCd with a cable clamp.....
Those clamps are after sales products, most board manufacturers will be supplying them.

^^^ no lid to stop the spontaneously combusting mcb's, rcd's iso's (whatever) from spontaneously combusting.

:)


where does the reg say it needs a lid? there are others with a lid that was just the first one i came across
The regulation uses the word enclosed, a metal CU without a lid would not be defined as enclosed.

You can still use plastic consumer units, the majority of CU's in domestics are under the stairs, if this compartment was fire lined and had a fire door  then plastic can be used. A surface mounted GRP meter cupboard could be used and comply with the regulations, so there are many options available to comply.

I would envisage new amendments coming over the next year, some will apply to the manufacturer and others to do with building control.

One such amendment to building control would be positioning of automatic fire detection (smoke alarms) within 2.5m of any CU.

I know people go on about torque settings and the like, torque is an exact science and is proven by mathematical formula. What it does do is give a known factor that is neither loose nor over tight. Using a torque screwdriver shows you have complied with the manufacturer instructions, and shown due diligence.

In the future I could see meter tails being made far more flexible than they are at present. This would remove a known problem of stress imposed on the main connections. Perhaps even boards supplied with meter tails already connected into a more permanent fixing?

All speculation I know but be prepared for new amendments, they will come.

 
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