Departures from bs7671, certification.

[odawire]

Hi, I have always made sure my installs have no departures from bs7671 but I'm doing a ccu change next week and have done some preliminary testing and the heating circuit (boiler and heating controls) has low IR readings, had a look in all obvious places and cant find any problems, had trouble breaking the circuit up as its a bit messy, client has just decorated so he doesn't want any damage to the house, seeing as its all fixed equipment (I'm unsure on the cable routes but id guess its buried less than 50mm at some point) is it acceptable to leave this circuit unprotected and note it on the departures section? all the earthing/bonding is mustard. Any experience on this would be appreciated, thanks.

 

[DPG]

Its not necessarily "faulty"

Is the circuit faulty or not? It trips the RCD - yes? Daz

 

[odawire]

With the greatest respect, don't "try" to rectify the fault, but make it clear that it MUST be sorted before you proceed further. If your test was 7 meg and that was an end to it, then all well and good. A note that IR tests were low would have covered you. However, as it is taking the RCD straight out, then there is something very wrong somewhere.
How would you feel if there's a fire due to this fault, and you'd walked away saying "I had a look, but nothing I could do"?

That's not what Im saying, its a bit more complicated then that, it may be that the client does not want any work done in which case I need a reason for the circuit to be on a rcd, which to be honest there isn't

 

[telectrix]

odawire, if you get the same reading L-E as N-E, then its one or the other with a load still connected. do continuity L-N first, then 250V L-N this will give you a better idea.

 

[Rockingit]

If you've got an IR measurement of 7MOhms, then you're chasing up a tree. 230/700000 = something too small to bother with, certainly not enough to trip a 30mA RCD. So, test and test again. Have you considered something as mundane as a borrowed neutral somewhere?

 

[odawire]

Is the circuit faulty or not? It trips the RCD - yes? Daz

Yes, which I assume is down to IR breakdown

 

[DPG]

That's not what Im saying, its a bit more complicated then that, it may be that the client does not want any work done in which case I need a reason for the circuit to be on a rcd, which to be honest there isn't

I don't get this, maybe I'm misunderstanding you. It's not a case of whether the circuit should or should not be on an RCD. The issue is the fact that the circuit should work fine if it is on an RCD, but it doesn't. The reason you are putting forward for not protecting it with an RCD is not a regs issue, it's because it won't work when it is fed from one. Daz

 

[odawire]

If you've got an IR measurement of 7MOhms, then you're chasing up a tree. 230/700000 = something too small to bother with, certainly not enough to trip a 30mA RCD. So, test and test again. Have you considered something as mundane as a borrowed neutral somewhere?

Yea, I have thought that, I will be checking that

 

[odawire]

I don't get this, maybe I'm misunderstanding you. It's not a case of whether the circuit should or should not be on an RCD. The issue is the fact that the circuit should work fine if it is on an RCD, but it doesn't. The reason you are putting forward for not protecting it with an RCD is not a regs issue, it's because it won't work when it is fed from one. Daz

My original question was about departures being noted on an EIC, but its turned into me turning my back on a dangerous situation which I haven't.

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Just a thought I would disconnect any zone valves or circulation pump I know from experience they can be a pain

Thanks, ill keep that in mind

 

[odawire]

odawire, if you get the same reading L-E as N-E, then its one or the other with a load still connected. do continuity L-N first, then 250V L-N this will give you a better idea.

Good point, ill keep that in mind

N-L was the same too

 

[Octopus]

Hi, should have explained, I have a rig I made up I use sometimes, its basically an rcd adaptor that I wire into and plug into a socket, when I did this it tripped, the IR reading was bouncing around I think it settled around 7Mohms across all points, I remember it was the exact same number. The reason Im asking is, I want to know if its acceptable to leave it off the RCD side if I have to, as I don't think I can leave them with no heating at this time of year, can I note it as a departure as the cable is probably less than 50mm deep

Maybe you should go back and retest the IR as I wouldn't expect the value you claim to trip an RCD if it really was across all 3 "points"

 

[Heisenberg]

Thanks for the reply, BS7671 does not require circuits to be upgraded to current regulations to be connected to a replacement ccu, only for it to be ascertained that they are not an immediate danger (which I would read as no C1's or C2's), GN3 even says there is no obligation to inspect or test any part of the installation!

Also found this : www.niceic.com/Uploads/File1950.pdf Guidance on cu replacement, which also says the same. interesting reading.

The document you refer to also says this:

Where a consumer unit is being replaced, additional protection by means of RCDs in accordance with Regulation 415.1 should be provided to the extent required by the current edition BS 7671, such as for:

• socket-outlets (Regulation 411.3.3 refers),
• mobile equipment for use outdoors (Regulation 411.3.3 refers),
• cables concealed in walls or partitions, where required by Regulations 522.6.6 to 522.6.8, and
• circuits of locations containing a bath or shower (Regulation 701.411.3.3 refers).

So if you are changing the CU you need to use RCD/RCBOs. You can't just avoid putting that circuit on a RCCD because it keeps tripping. And sod what the customer says, it won't be him appearing in front of the men in funny wigs if it all goes south. Do it the way it's meant to be done or walk away, simples.

 

[odawire]

The document you refer to also says this:

Where a consumer unit is being replaced, additional protection by means of RCDs in accordance with Regulation 415.1 should be provided to the extent required by the current edition BS 7671, such as for:

• socket-outlets (Regulation 411.3.3 refers),
• mobile equipment for use outdoors (Regulation 411.3.3 refers),
• cables concealed in walls or partitions, where required by Regulations 522.6.6 to 522.6.8, and
• circuits of locations containing a bath or shower (Regulation 701.411.3.3 refers).

So if you are changing the CU you need to use RCD/RCBOs. You can't just avoid putting that circuit on a RCCD because it keeps tripping. And sod what the customer says, it won't be him appearing in front of the men in funny wigs if it all goes south. Do it the way it's meant to be done or walk away, simples.

Typical guidance contradicting itself, once again, this was a question about departures being noted on certificates, and talking about me being in court for leaving dangerous situation, is it impossible to have a normal conversation on this forum?

 

[R G]

Best to get this sorted before you do any work , if you speak to the customer and explain the problem they would see your point , but if you did the job as it stands now , the client probably wouldn't bother getting it sorted

 

[fog]

can be nightmare, personnally you could try taking some temporary 1.5/2.5 mm flex directly to fused connection unit, from board or your RCD socket, eliminating anything else on circuit see if that works, then eliminate heating circuit parts i.e pump, valves, i often take temporary flex to circuit loads eliminating other loads on circuit, to see where the problem is? but it must be RCD protected on a cu change. as said before if the fault still exists more investigation required, explain that the work must be carried out, otherwise no point in cu change. be wary of untruthful customers who say nothing is wrong, getting a quote and fixed price on board change is a good way of customer getting there faults fixed? when i first started got had on this one had to rewire most of upstairs lighting circuit due to rodent damage, customer just kept saying you quoted x thats all you getting

 

[Heisenberg]

Typical guidance contradicting itself, once again, this was a question about departures being noted on certificates, and talking about me being in court for leaving dangerous situation, is it impossible to have a normal conversation on this forum?

Where exactly is the contradiction? You have already been told by Richard Burns that your interpretation of the 'departures' section is incorrect, so I'll say it again. You can't use the 'departures' section to mitigate the fact that you have not installed, or are intending to not install, the CU in accordance with BS7671.

 

[DJ Ovengloves]

Wow, I mean wow. Just because your peers are telling to do a job properly and quite clearly you don't have a clue to do so, there no need to start throwing your toys. Either fix the problem (if you can) or walk away, ensuring you let your customer why. Sorry mods, but I find this kind of attitude disgusting if I'm honest.

Typical guidance contradicting itself, once again, this was a question about departures being noted on certificates, and talking about me being in court for leaving dangerous situation, is it impossible to have a normal conversation on this forum?

 

[Octopus]

Agree 110%^^^^^^

 

[Sintra]

Typical guidance contradicting itself, once again, this was a question about departures being noted on certificates, and talking about me being in court for leaving dangerous situation, is it impossible to have a normal conversation on this forum?

Mate you have asked a question and been given the correct guidance by different members. Just because you may not like what you hear is not the fault of the forum.

 

[odawire]

Where exactly is the contradiction? You have already been told by Richard Burns that your interpretation of the 'departures' section is incorrect, so I'll say it again. You can't use the 'departures' section to mitigate the fact that you have not installed, or are intending to not install, the CU in accordance with BS7671.

In one part of the document it says rcd protection should be required for buried cables, but in another part (and in the regs) it says C3 can be connected to a new CCU, that is a contradiction.

 

[odawire]

Wow, I mean wow. Just because your peers are telling to do a job properly and quite clearly you don't have a clue to do so, there no need to start throwing your toys. Either fix the problem (if you can) or walk away, ensuring you let your customer why. Sorry mods, but I find this kind of attitude disgusting if I'm honest.

The point im making is tht is not the question I asked, Im perfectly able to diagnose and fix wiring faults, but that was not my question, Im not throwing any toys anywhere, can you please explain what you mean when you say you find my attitude disgusting?