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17th Ed. Consumer Units isn't really about 314. 314 was there before. It's about the increased use of 30mA RCDs - bathrooms, all sockets, buried cables. These can all be sorted with a single 30mA RCD at the origin. It's 314 that then puts the damper on this. The 'inconvenience' is decided on a...

BAS, are we to assume that other answers of yours are not to be taken seriously?

I think you mean RCD, not mcb. Unless the customer is willing to pay for more, this is going to be the only option. And I think it looks like becoming the norm.

Then we agree. The Designer takes on an assumed responsibility to minimize to a reasonable level. He is the comptent person and can't ignore it altogether so a reasonable distribution of circuits in a dual RCD boards should suffice in many situations. Then your addition must comply with the...

I agree with all your points, but I think you've inadvertently slipped here. It's impact protection that is causing this gnashing of teeth with the 17th. Leakage is the main concern for bathrooms. There has never been a guarantee of discrimmination with Type S RCDs for all faults (i.e. high...

Why stop there? What about tails or earthing conductor? How unreasonable is it to implement a significant safety change of the 17th by installing RCD protection? To follow this to it's extreme, if a house was wired in 1946, then it would be OK to 'replace' the old installation with an exact...

You have changed the protective device on very circuit and have failed to change the protection to one which complies with the current edition of BS767. Therefore you cannot certify that the work you have done complies with the 17th Edition. And you have taken payment for a professional service...

In my opinion, you're focusing on the wrong word. 'Minimize' is attached to the word 'inconvenience'. It is the word inconvenience that is the main thrust of things. Once we have established what the inconvenience is or could be, we can decide what to do about it. The Regs would like us to...

There is no specific requirement to have local isolation for socket outlets. Unless of course there is a specific reason for you to require them?

The reason I don't like doing it like that is that I think it's preferable to enter the 'corrected' maximum figure for comparison as it speeds up re-verification when I double check everything. Once you've entered the OSG figures a few times, you memorize them and you know instantly whether a...

I guess the way to look at it is to ask why is the info requested on the test sheet? Seems little point putting a figure which may not be applicable. Especially as that figure is recorded in a British Standard anyhow. The purpose of entering the measured value is to record the value and also to...

:oops: can I delete that one...miles away...too many thnigs at once...

Gary, you're not wrong. It's just that there can be problems testing directly on terminals. I've always tested in circuit as I believe it's always best to make testing as realistic as possible. Doing so also 'repeats' other tests in a round about way i.e. cpc to CU. I know there has been a...

Wow. I wonder if the reading was measured from the front via an adaptor. Marbo sockets in particular are very flaky if measured this way. MK always rock solid though and Crabtree always good.

You should be commended for measuring them and noting the results. :D

Gary, the preference is to test RCDs at an appropriate point(s) in the circuit. I seem to recall ERA (or someone) mentioning this in an RCD paper. Testing on the terminals can give odd/incorrect readings and with some RCBOs very odd. So I would say that the RCD should be tested from each...

R2 refers to a circuit protective conductor, not a bonding conductor. By all means enter a resistance value for bonding conductors if you wish, but don't refer to them as R2 values.

These are design figures and represent the absolute maximum figures given the test conditions referenced in BS7671. BS7671 makes this clear at the foot of the Zs tables in Chap. 41. As such, the maximum figure entered on the sheet should be the maximum permissable figure taking into account...

Wooden backboards are unlikely to be of significance in an already well-established fire. I always prefer hardwood though as it's harder to set alight than softwood.

The most surprising thing is that he never appears to be short of work. There are lots of electicians winding down at the moment, looking at their books, scratching their heads as to marketing options etc. and he seems to come out of jail and pick up work all over the place - and know how to...