New 18th Edition.

[davesparks]

It's useful for fault finding purposes in relation to cumulative earth leakage. I don't know the workings of RCDs inside out. But I presume that over time the mA threshold can change, which is not a bad thing to have documented. I understand what you are saying, but given that it takes no time to carry out I prefer to record it.

I find it a bit odd that we don't test MCBs functionality.

Fault finding yes, but that is a bit different to recording it on a test sheet.
The trip threshold won't change, it's set at the factory and that's it. I'd only want to see it recorded for variable RCDs where by their very nature it can change.

Carry out the unnecessary test by all means, but don't force the rest of us in to having to do it and write the result down.

 

[andyb]

I agree partly with what you are saying Andy! But why should I check what the condition of the meter is like!? A quick glance over to see if it looks 100% safe, but that's about it. Maybe the meter readers should be checking this. I think it's partly to do with the smart meter rollout and passing the buck myself.

If the DNOs tails need upgrading I ring them. The main earth is checked also. I don't tick a box to say that their service cable is OK though. That's N/V for me.

Ok then TGO, let's agree to partly disagree.
Though I think you're wriggling a bit now. It seems you are doing about as much as we all do, ie a quick look over. You just don't like to tick the box.

 

[NDG Elecs]

Fault finding yes, but that is a bit different to recording it on a test sheet.
The trip threshold won't change, it's set at the factory and that's it. I'd only want to see it recorded for variable RCDs where by their very nature it can change.

Carry out the unnecessary test by all means, but don't force the rest of us in to having to do it and write the result down.

Didn't realise the threshold was unchanging over time. I assumed it may well alter by a couple of mA's. I find a lot of RCDs, when ramped, can trip on the low side <23mA. I would expect the factory setting to be say 4mA higher. 90% (27mA) seems a good threshold to me!

It isn't me potentially forcing you Dave, it be the brains of the IET in 2018 possibly! So are you happy to tick/nv/lim/na all the boxes on the inspections. I do read them each and every time and fill in accordingly, but a good few are daft.

 

[NDG Elecs]

Ok then TGO, let's agree to partly disagree.
Though I think you're wriggling a bit now. It seems you are doing about as much as we all do, ie a quick look over. You just don't like to tick the box.

Feeling rebellious after three beers tonight, that's what it is!

 

[davesparks]

Didn't realise the threshold was unchanging over time. I assumed it may well alter by a couple of mA's. I find a lot of RCDs, when ramped, can trip on the low side <23mA. I would expect the factory setting to be say 4mA higher. 90% (27mA) seems a good threshold to me!

It isn't me potentially forcing you Dave, it be the brains of the IET in 2018 possibly! So are you happy to tick/nv/lim/na all the boxes on the inspections. I do read them each and every time and fill in accordingly, but a good few are daft.

Why do you think 23mA is low? Afaik the standard requires them to trip >15 mAand <30 mA.

One problem that will arise is people who don't know better replacing RCDs because they are 'faulty' when they don't trip dead on 30mA.

 

[Risteard]

Why do you think 23mA is low? Afaik the standard requires them to trip >15 mAand <30 mA.

Indeed it does, which is why I never bother with ramp tests - a waste of time except perhaps for trying to establish the leakage on an appliance etc.

But half I delta n and I delta n will prove that the RCD is functioning correctly.

 

[NDG Elecs]

Why do you think 23mA is low? Afaik the standard requires them to trip >15 mAand <30 mA.

One problem that will arise is people who don't know better replacing RCDs because they are 'faulty' when they don't trip dead on 30mA.

Not au fait with the standard Dave, and didn't know it was between 15-30mA. Learn something new every day and all that. I have never replaced a RCD unless the trip times were incorrect, and I wouldn't do so if it ramped on the low side. If an RCD is tripping then obviously better to find and remedy the root causes. I am just surprised that the majority of RCDs I have tested are generally around 23mA. Guess the manufacturers are going for the middle ground.

 

[davesparks]

Not au fait with the standard Dave, and didn't know it was between 15-30mA. Learn something new every day and all that. I have never replaced a RCD unless the trip times were incorrect, and I wouldn't do so if it ramped on the low side. If an RCD is tripping then obviously better to find and remedy the root causes. I am just surprised that the majority of RCDs I have tested are generally around 23mA. Guess the manufacturers are going for the middle ground.

It is, and that is what the 1/2x and 1x test is all about!
There is also a requirement that the touch voltage be limited to 50V, which I guess may have some bearing on the actual trip setting (pure guess on my part)

 

[colshaws]

Had my Elecsa assessment today and asked about proposed changes in the 18th and one that was mentioned was the possibility of a requirement for C.U 's to be all RCBO as standard to avoid nuisence tripping.

 

[Darkwood]

I think we are all forgetting what is for me the most important question relative to the new 18th edition and it is 'What colour will the cover be?'

 

[andyb]

I think we are all forgetting what is for me the most important question relative to the new 18th edition and it is 'What colour will the cover be?'

Red at a guess.

 

[Octopus]

Had my Elecsa assessment today and asked about proposed changes in the 18th and one that was mentioned was the possibility of a requirement for C.U 's to be all RCBO as standard to avoid nuisence tripping.

Best that they RAM HOME to some of the muppets that a single RCD board isn't acceptable and spell it out in the regs properly then.

Me thinks BEAMA have got in on the act and want this as a revenue and profit making activity!

 

[Deleted member 26818]

Blue next, then brown.

 

[Octopus]

Blue next, then brown.

then green & yellow?

 

[Deleted member 26818]

Red before green.