Posted by & filed under Electrical estimating, estimating Tips & Hints.

Out now, 1st January 2015, The new yellow book will come into effect from 1st July and it has something for everyone. I would encourage you to attend a one day course to become familiar with the new changes to take effect, but I will bullet point some of them.

The BIG one for me is cable shall be fixed with steel fixings so they don’t create a dangerous washing line tangle when all the tie wraps melt. Regulation 521.11.201. Out goes plastic conduit and Trunking and in comes steel conduit and trunking. This change has created new products to solve the problem, and I think this is one where there will be much debate over the coming months.So when existing installation are periodically tested and inspected they may not comply with this regulation, creating a large rewire/refurbishment market

So what else is note worthy?

The new edition has a little marker on the RHS flagging it’s a new regulation, which is good, because there’s a lot.

Regulations ending 200 apply to the UK only, they were 100.

Definition extended 134.2.1 not just competent, now skilled and competent to verify that the requirements of the standard have been met.

From 1st July installation must be designed and certified to the IET Wiring Regulation 17th Edition, prior to this date they can be designed and certified to Amendment 2 or 3.
Within Domestic premises consumer units shall be manufactured from non-combustible material or be housed in a cabinet or enclosure of non-combustible material However regulation 421.1.201 is a transitional and doesn’t come into full effect until 1st January 2016. Will there be a new wonder material? Or are we using metal consumer units, or should architects design a space for them.

There is no published definition for “Non-combustible”.

Regulation 421.1.201 may have far wider implications, extending to wiring accessories.

The next big one is the introduction in the definition of the Auxiliary circuit, and the requirement to test it. Auxiliary will include things like bus wires for emergency lighting, BMS, emergency stop push buttons and these test results and now recorded on the new model forms, greatly extended.

Socket outlets not exceeding 20A shall have RCD’s unless you undertake and document the risk assessment. This is 411.3.3 and applies ONLY to none domestic properties. Unless labelled for a specific item of equipment.

Zs have all been adjusted down by 5% due to Cmin, to take account of wider voltage variations in some European countries. So effectively shortening the length of the circuit or increasing the cable size.

The testing process is now greatly widened including auxiliary circuits, greater breadth of RCD testing and only to be undertaken by a skilled persons competent to verify that the requirements of the IET wiring regulations have been met.

Thanks to pass training workshop.