Normally I'd expect to see  0,4 sec (TNx), or 0.2 sec (TT) for finals or 5 seconds(TNx) or 1sec (TT) for large submains and really mean longest ADS time

permitted by the regs. as the max limit.


The test results however should always be shorter ? or we have the wrong sort of RCD fitted, or something is broken.

description


1mm T&E or 25mm SWA or what ever. If mixed, the smaller. so a mix of 1,5 and 1,0 t and E would be treated as if all 1mm if there is not room on form for both.

M.

Hello Alan


When you say you're looking to add some labels - I assume - from the picture you have posted -  you mean you're going to put a Schedule of circuit details stuck somewhere near to the DB or perhaps in the front lid?


Maximum disconnection times See 411.3.2  and typically see table 41.1 page 59 for Final Circuits disconnection times.

Look along the top of the table and you will see 120V<Uo<230 - this means you use the values below this for Live to Earth values of (in theory) less than or equal to 230V.

This bit includes 400V systems as the live to earth value of a three phase system is still less than or equal to 230V in theory. So on a TN System (AC electrics) the maximum disconnection time is 0.4 and on a TT system the maximum disconnection time is 0.2 seconds  


411.3.2.3 and 411.3.2.4 gives you disconnection times for a distribution circuit - typically the circuit supplying a DB for example.


I'm unsure how that form you have pasted can be copy right as it seems to be a fairly standard generic sheet of basic information. All that asks for is what size of RCD are you using on a given circuit. 


When you come to a test form and it askes for the RCD test results, the value you input depends on what the RCD is doing.

If the RCD is there for Fault protection (All RCDs greater than 30mA, (Usually) but in a TT system the 30mA RCDs are often there for fault protection too (in a typical household installation)

I'd input the X 1 test result, for all of the RCDs greater than 30mA as theres no need to do a x 5 test for those and for the 30mA RCDs where its also there for both fault and additional protection, then use the x 5 figure in the test sheet results box.

If the RCD is there for solely for additional protection only, I'd use the x 5 figure for the test sheet.

And For type of wiring - most forms I've seen use the following:


A - is for PVC/PVC such as twin and earth

B - PVC cables in metalic conduit

C - PVC Cables in non metalic conduit

D - PVC cables in metalic Trunking

E - PVC cables in non-metalic Trunking

F - PVC SWA Cables

G - XLPE SWA Cable

H - Mineral Insulated Cables

O - Other (I usually put BS8436 Cables here or FP, which is similar and my software allows a space to input what "O" cable is)

Always read the question carefully.


It doesn’t ask for the RCD trip times, it asks for the operating current.

not on this form though it seems though it is  pretty crummy copy, I am fairly sure

I can squint and read is as Max.disconnection time permitted by BS7671.. Funny old NICIEC eh..


.

It’s rare to see one on a consumer unit.

oh yes, domestically I'd go so far as to say round here its rare enough that the one that says "upstairs lights" in felt tip actually relates to lights on either of the breakers nearest to the label, its almost as likely to be written next to conservatory sockets or something..

Commercial tends to be better. Usually.

M

Do you currently use any software for your certification?

Thanks all for the comments and advice


Just to confirm the bit you are showing does say maximum disconnect time.

Looks like you agree with my first thought of stating 0.4 S for a TN system in my case. Also looking carefully it's asking for number of seconds rather than mS, therefore also implying this is whats required.


The codes for type of wiring are interesting, in my training I haven't seen this so far. As the form doesn't have a key for the codes and this is just an NICEIC thing rather than a standard I think it will just cause confusion.

I am just going to squeeze in T+E or SGL for singles or leave it blank as it's fairly obvious anyway.