Discuss DB installed connected & tested in the UK Electrical Forum area at ElectriciansForums.net
yes but as Suffolk spark has said it will still trip the upfront RCD so there is no discrimination in the event of a neutral earth fault.A neutral fault on that circuit,will trip the individual rcbo’s on the lighting panel,before tripping the time delay Rcd.
This came with the rcb’os,providing a upfront Rcd is used,it’s ok-ish,I realise discriminating may not be ideal,but what else can you do,on a TT system.
yea,your talking about the N/E faults that may happen,discrimination will occur when there’s a L/E fault.
Who on earth uses double pole rcbo’s,.
This came with the rcb’os,providing a upfront Rcd is used,it’s ok-ish,I realise discriminating may not be ideal,but what else can you do,on a TT system.
yea,your talking about the N/E faults that may happen,discrimination will occur when there’s a L/E fault.
Who on earth uses double pole rcbo’s,.
Agree.Not double pole but switched neutral. These would of done the job.
Wylex NHXS1B32 32 Amp 30ma Type B 1 Module RCBO - Edwardes - https://www.edwardes.co.uk/en/products/wylex-nhxs1b32-32-amp-30ma-type-b-single-pole-1-module-rcbo-?utm_medium=google_shopping&utm_source=google&utm_campaign=google_shopping&gclid=EAIaIQobChMIxemvxrWc2wIVypPtCh23egO4EAQYASABEgLWBfD_BwE
You are literally talking milli seconds before the upfront RCD trips aswell as the RCBO. what's the installation method of the distribution circuit feeding the loxone?Ok,if the fault happens on the 30ma protected circuits,theses would trip before the time delay Rcd.
That’s why the time delay Rcd is installed.
It’s no-different set up than the above literature supplied by the manufacturers.
I can see your points about the N/E scenario,thinking that would be the worst case.
When this set up was introduced years ago,it worked well,preventing complete disconnection, of power.
Yeah but even when the downstream RCBO trips the N-E fault will still remain and therefore will trip the main RCD after the time delay because the RCBO will only disconnect the line of the CCT the neutral and earth are still in the bars and the fault will be seen by the RCD main switch. IMHO the best way to sort it and achieve discrimination is to change the MCB to an RCBO and have an upfront isolator rather than a main switch.Ok,if the fault happens on the 30ma protected circuits,theses would trip before the time delay Rcd.
That’s why the time delay Rcd is installed.
It’s no-different set up than the above literature supplied by the manufacturers.
I can see your points about the N/E scenario,thinking that would be the worst case.
When this set up was introduced years ago,it worked well,preventing complete disconnection, of power.
Agree.Not double pole but switched neutral. These would of done the job.
Wylex NHXS1B32 32 Amp 30ma Type B 1 Module RCBO - Edwardes - https://www.edwardes.co.uk/en/products/wylex-nhxs1b32-32-amp-30ma-type-b-single-pole-1-module-rcbo-?utm_medium=google_shopping&utm_source=google&utm_campaign=google_shopping&gclid=EAIaIQobChMIxemvxrWc2wIVypPtCh23egO4EAQYASABEgLWBfD_BwE
Yea I can see where everyone is coming from,we are talking about a n/e fault here,I know it’s on aTT system,but realisticallyYeah but even when the downstream RCBO trips the N-E fault will still remain and therefore will trip the main RCD after the time delay because the RCBO will only disconnect the line of the CCT the neutral and earth are still in the bars and the fault will be seen by the RCD main switch. IMHO the best way to sort it and achieve discrimination is to change the MCB to an RCBO and have an upfront isolator rather than a main switch.
Yeah but even when the downstream RCBO trips the N-E fault will still remain and therefore will trip the main RCD after the time delay because the RCBO will only disconnect the line of the CCT the neutral and earth are still in the bars and the fault will be seen by the RCD main switch. IMHO the best way to sort it and achieve discrimination is to change the MCB to an RCBO and have an upfront isolator rather than a main switch.Ok,if the fault happens on the 30ma protected circuits,theses would trip before the time delay Rcd.
That’s why the time delay Rcd is installed.
It’s no-different set up than the above literature supplied by the manufacturers.
I can see your points about the N/E scenario,thinking that would be the worst case.
When this set up was introduced years ago,it worked well,preventing complete disconnection, of power.
even with no current flowing the act of joining the N and earth will trip the rcd try it on a dual rcd board switch off the mcb for say a socket circuit and short N-E the RCD will trip so it makes no difference if the RCBO trips in that board it will still trip the upfront RCD it isn’t compliant with BS7671 if you haven’t achieved discrimination in all fault conditions of final circuits and should be noted as a departure on the EIC along with an attached risk AssessmentYea I can see where everyone is coming from,we are talking about a n/e fault here,I know it’s on aTT system,but realistically
These faults may be happening all the time,on most earthing systems,with negligible currents flowing.
N/e faults have always been a pain,& so be it if all power is disconnected,also if the rcbo disconnects that circuit surely that prevents any fault being on that circuit ie:N/E.,no current will flow to Earth ,arguing the fact the rcbo will trip on a N/E fault.
This is getting mighty confusing.
But it will still only trip the affected CCT the fault will remain until rectified but the the circuit will not be able to be energised which should mean that no dangerous current should flow from nuetral to earthThat applies to all time delay DB’s.If the mcb is changed to a rcbo,then a main switch installed,IMO,that’s makes it worse,N/E remains.
Never had a torque driver...and never had a problem.My issue with the Lewden boards is the advised torque settings, I have two torque drivers and with either if I torque them to manufacturers settings it has a tendency to damage the rcbo screws.
Gotta love the old Wylex boards actually I think Wylex are returning to double screws for the tails anywayNever had a torque driver...and never had a problem.
We should go back to double screwed terminals.....it'd give everybody two chances of getting at least one right. Like these, maybe.
View attachment 42407
......with main switch on the right, of course.Gotta love the old Wylex boards actually I think Wylex are returning to double screws for the tails anyway
Gotta love the old Wylex boards
nah that bugs me you don’t read from right to left do you?......with main switch on the right, of course.
nah that bugs me you don’t read from right to left do you?
Reply to DB installed connected & tested in the UK Electrical Forum area at ElectriciansForums.net
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