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Out of interest I went to Electrical Safety Council website and looked at the Best Practice Guides.
They say where the ELCB-v works as designed and there are no parallel paths then Code 3, if there are parallel paths then code 2.
I don't agree with their advice, but never the less in the light of a so called safety organisation giving that advice one can hardly chastise any electrician from following it.
But the question remains. How can one test a device when the test equipment required is no longer available?
At 100 Ω and 45 V the current required to trip would be 450 mA I seem to remember the one I tested was more like 250 Ω which means 180 mA but the problem is our tester is designed to work on 230 V not 45 V and to apply the 45 V means completely disconnecting and these devices were the main isolator so it would require drawing on DNO fuse to test.
As already stated from 1974 when the supply regulations were changed with a TN supply it was likely safer without any ELCB than with an ELCB-v.
The more I think about the more I reach the conclusion that unless you have the equipment required you should refuse the job. The report should simple state "We do not have the equipment required to test the now discontinued ELCB-v installed in the installation. Either it need replacing with a RCD or you need to find some one with the antiquated test equipment and even if you do find some one able to test it they will still issue at least a Code 3." unless you have the test equipment of course.
With the exception of incorrect polarity all faults getting Code 1 have immediate danger and clearly having an ELCB-v poses no danger in its self so unless there is physical damage can't be Code 1. So the selection is Potential dangerous or Improvement recommended. One would recommend improvement so the consideration is if it's potential dangerous.
First on the ESC BPG is "Absence of a reliable and effective means of earthing for the installation" and I would consider having an ELCB-v ticks that box. Lack of RCD protection also flags up a Code 2 where cables are buried less than 50mm etc.
But it quotes
There are a few things I don't agree with in the document it says Code 2 means the item needs require further investigation being remedied or investigated respectively as a matter of urgency. This means of course any Code 3 does not need correcting as a matter of urgency. I am sure it's not intended to be read that way but that's what it says.
The RCD question means that where cables are buried then all circuits get a Code 3 or 2 because of no RCD so any other Code 3 faults get hidden as the RCD issue is repeated again and again.
The Absence of supplementary bonding for installed Class II equipment where required (such as in a location containing a bath or shower), in case the equipment is replaced with Class I equipment in the future. Gets Code 3 to my mind having this in the notes yes but it should not be coded. We have some scheme operators saying you can use the three core earth wire for power with Class II tank thermostats, and others saying it a failure not to have the earth wire available.
So we have a situation where one scheme provider will give an installation a clean bill of health and another one with give the same installation a Code 3.
In one breath we say BS7671 is not retrospective and in the next we Code all the faults which were not faults when installed. Bring back Code 4.
They say where the ELCB-v works as designed and there are no parallel paths then Code 3, if there are parallel paths then code 2.
I don't agree with their advice, but never the less in the light of a so called safety organisation giving that advice one can hardly chastise any electrician from following it.
But the question remains. How can one test a device when the test equipment required is no longer available?
At 100 Ω and 45 V the current required to trip would be 450 mA I seem to remember the one I tested was more like 250 Ω which means 180 mA but the problem is our tester is designed to work on 230 V not 45 V and to apply the 45 V means completely disconnecting and these devices were the main isolator so it would require drawing on DNO fuse to test.
As already stated from 1974 when the supply regulations were changed with a TN supply it was likely safer without any ELCB than with an ELCB-v.
The more I think about the more I reach the conclusion that unless you have the equipment required you should refuse the job. The report should simple state "We do not have the equipment required to test the now discontinued ELCB-v installed in the installation. Either it need replacing with a RCD or you need to find some one with the antiquated test equipment and even if you do find some one able to test it they will still issue at least a Code 3." unless you have the test equipment of course.
With the exception of incorrect polarity all faults getting Code 1 have immediate danger and clearly having an ELCB-v poses no danger in its self so unless there is physical damage can't be Code 1. So the selection is Potential dangerous or Improvement recommended. One would recommend improvement so the consideration is if it's potential dangerous.
First on the ESC BPG is "Absence of a reliable and effective means of earthing for the installation" and I would consider having an ELCB-v ticks that box. Lack of RCD protection also flags up a Code 2 where cables are buried less than 50mm etc.
But it quotes
Under heading for Code 3.
There are a few things I don't agree with in the document it says Code 2 means the item needs require further investigation being remedied or investigated respectively as a matter of urgency. This means of course any Code 3 does not need correcting as a matter of urgency. I am sure it's not intended to be read that way but that's what it says.
The RCD question means that where cables are buried then all circuits get a Code 3 or 2 because of no RCD so any other Code 3 faults get hidden as the RCD issue is repeated again and again.
The Absence of supplementary bonding for installed Class II equipment where required (such as in a location containing a bath or shower), in case the equipment is replaced with Class I equipment in the future. Gets Code 3 to my mind having this in the notes yes but it should not be coded. We have some scheme operators saying you can use the three core earth wire for power with Class II tank thermostats, and others saying it a failure not to have the earth wire available.
So we have a situation where one scheme provider will give an installation a clean bill of health and another one with give the same installation a Code 3.
In one breath we say BS7671 is not retrospective and in the next we Code all the faults which were not faults when installed. Bring back Code 4.
