rcbo's don't cut the blue cable!

[mrloy99]

I was on a job last year,big multiroomed hotel,each with their own consumer unit which entailed the installation of at least 2 rcbo's per unit.One of my jobs was to go round and change every rcbo (about 400)
in all! ,as the previous spark had shortened the curly blue leads ,presumably to tidy things up.Some consultant came along and he had apparantly been in touch with MK who in their superior wisdom,decided that the reason their rcbo's wern't tripping within their manufactors stated limits was that these leads were not designed to be shortened. I have yet to see any information advising of this on their
product information and indeed have been guilty of performing this sin myself on one or two occasions,though I did not see any problems with
test results that I achieved. Thank god I wasn't paying for it!!
I would be most interested to know if other tradesmen are aware of this or have had similar issues in the past.

 

[Spudnik]

I just cannot see why shortening a flylead on an RCBO is going to cause problems.

The reason that their RCBO's aren't tripping in time is because they are carp

The only MK stuff that i will use now is their accessories, and even they are not as good as they used to be.

Then again, most manufacturers are the same.

 

[simopesh]

I was on a job last year,big multiroomed hotel,each with their own consumer unit which entailed the installation of at least 2 rcbo's per unit.One of my jobs was to go round and change every rcbo (about 400)
in all! ,as the previous spark had shortened the curly blue leads ,presumably to tidy things up.Some consultant came along and he had apparantly been in touch with MK who in their superior wisdom,decided that the reason their rcbo's wern't tripping within their manufactors stated limits was that these leads were not designed to be shortened. I have yet to see any information advising of this on their
product information and indeed have been guilty of performing this sin myself on one or two occasions,though I did not see any problems with
test results that I achieved. Thank god I wasn't paying for it!!
I would be most interested to know if other tradesmen are aware of this or have had similar issues in the past.

Absolute rubbish mate! I had the same claim by Wylex not long ago. However, it was hard for them to justify the above rubbish claim when I had a totally decent working RCBO with trimmed neutral.
It is the cheap coil that they are using, not the trimmed neutral. (No logic to such claim)
That is why I prefer to use Hager or Legrant these days, a lot better quality then the above well “known” brands.

 

[sivoodoo]

surley from a mathamatical point would it not be more efficient, less restitance? though we would be talking zillionths of a fraction... what am I on about?? need more beer...

 

[12345aob]

when I did my own board (6way with 5 ced rcbo's) I was comprimised with room and I had to cut the leads- there just too long. do any manufacturers do a shorter fly lead for smaller boards?

 

[KNIPEX]

just to go the otherway, i had a 24tpn mem db and the rcbo blue flylead was too short and did not reach the neutral bar

 

[mrloy99]

surley from a mathamatical point would it not be more efficient, less restitance? though we would be talking zillionths of a fraction... what am I on about?? need more beer...

I think it was pure bollox meself,but I was getting paid to change them and the origional ones were getting scrapped(i managed however to divert a few into my toolbag for use in homers) I recon it cost them about 12grand!plus my labour.
But who are we to reason why? I wouldn't mind another one of those
jobs.

 

[sivoodoo]

ill give you a hand, I will hold the scissors,er i mean side cutters...

 

[benji]

merlin gerin tell you to cut to length the blue & the white leads in the info. that comes with the rcd
yours benji

 

[hasel5]

Had the same problem years ago with mem rcbos spoke to mem and they said as long as within the times alowed in bs7671 then all ok. Readings were within the regs but still seemed slow.this seems to be a common problem with these devices

happy new year from the vendee in france