BS3036 breaking capacity and PFC..

[HappyHippyDad]

Afternoon....

I have just completed an EICR and am unsure if the Wylex BS3036 fuses require a code due to their breaking capacity related to the PFC.

Firstly I would like to identify if they are S1A, S2A or S4A as that would solve the problem of the PFC being 1.35kA, however I dont think its going to be possible to identify them as there are no markings indicating this information.

So I will put 1kA for breaking capacity which is < PFC!

Guidance note 3 says that you can take the s/c capacity of the fuses to be 16KA when:

the current ratings of the devices don't exceed 50A
The d/b is a 5486-13 or better
it is supplied through a type 2 BS1361 fuse rated at no more than 100A

But if the above is acceptable then I cant quite see the point in having a breaking capacity rating on fuse/MCB if we are going to ignore it?

Do most of you accept GN3 and would not be concerned? Or would you want to change for MCB's with a higher breaking capacity?

I have to admit I do not have a copy of GN3 so have just found the above paragraph on the internet, if I had the copy in my hand and could read it thoroughly I would find it easier to make a decision.

 

[Farmelectrics]

google it

 

[trev]

https://www.google.co.uk/url?sa=t&r...=KV-PmyZ7YY8ifdTHlVZ-pw&bvm=bv.80642063,d.ZGU

 

[Plonker 3]

You need to put N/V (not verified) for the Ka rating of the OCPD if its not present. Then code it accordingly on your report.

 

[Farmelectrics]

like it trev

 

[Guest55]

are you ready to carry out EICR's when you still have to come on the forum every day to get help with all your jobs ?

sorry but inspections require a level of experience you do not possess.

 

[Farmelectrics]

your ruthless biff lol

 

[Guest55]

that was as discreet as i could put it , and it needed to be said for the safety & well being of all concerned

 

[Plonker 3]

To be fair to hhd he has researched for a answer before asking unlike some on here. He has also shown he is capable of thinking outside the box a little bit, I am sure we have all had to look up these sort of things before.

Has he got the experience and knowledge to carry out a EICR I dont know bit at least he seems to be attempting to do it properly rather than just guessing his way through it.

 

[Guest55]

To be fair to hhd he has researched for a answer before asking unlike some on here. He has also shown he is capable of thinking outside the box a little bit, I am sure we have all had to look up these sort of things before.

Has he got the experience and knowledge to carry out a EICR I dont know bit at least he seems to be attempting to do it properly rather than just guessing his way through it.

well thats just fine & dandy , but the customer could have been handed a report recommending replacement of his rewirables for no other reason than theres no PSC rating on the side of the fuse carrier.

and in my mind 3036's will deal with 3kA fault current all day long...........

 

[telectrix]

see your comment, dilb, and agree. HHD has shown his dedication to the trade and, although having come in through the Electrical Trainee route, is keen to get it right and deserves all the help we can give him, respect.

 

[ImpededLoop]

Guidance note 3 says that you can take the s/c capacity of the fuses to be 16KA when:

the current ratings of the devices don't exceed 50A
The d/b is a 5486-13 or better
it is supplied through a type 2 BS1361 fuse rated at no more than 100A

But if the above is acceptable then I cant quite see the point in having a breaking capacity rating on fuse/MCB if we are going to ignore it?

Do most of you accept GN3 and would not be concerned? Or would you want to change for MCB's with a higher breaking capacity?

I have to admit I do not have a copy of GN3 so have just found the above paragraph on the internet, if I had the copy in my hand and could read it thoroughly I would find it easier to make a decision.

As you say, if the upstream BS1361 has a high enough breaking capacity, then you don't need to worry.

Always worth noting it on the report though.

 

[HappyHippyDad]

https://www.google.co.uk/url?sa=t&r...=KV-PmyZ7YY8ifdTHlVZ-pw&bvm=bv.80642063,d.ZGU

Cheers Trev,
But that still shows the breaking capacity could be anywhere from 1-4kA which makes quite a difference with a PFC of 1.35kA.

You need to put N/V (not verified) for the Ka rating of the OCPD if its not present. Then code it accordingly on your report.

It's a difficult one to code Dillb.. I think it's potentially dangerous as PFC > breaking capacity but GN3 states otherwise.

are you ready to carry out EICR's when you still have to come on the forum every day to get help with all your jobs ?

sorry but inspections require a level of experience you do not possess.

Yes.

1.1 threads started p/week..... daily? I do get picky about inaccurate statistics!!!!

But thanks for the input

 

[HappyHippyDad]

well thats just fine & dandy , but the customer could have been handed a report recommending replacement of his rewirables for no other reason than theres no PSC rating on the side of the fuse carrier.

and in my mind 3036's will deal with 3kA fault current all day long...........

Thats a fair point..

Which page is that on Biff? :smile5:

edit ..................

sorry, that was a bit cheeky! Couldn't resist!

 

[Octopus]

To be fair to hhd he has researched for a answer before asking unlike some on here. He has also shown he is capable of thinking outside the box a little bit, I am sure we have all had to look up these sort of things before.

Has he got the experience and knowledge to carry out a EICR I dont know bit at least he seems to be attempting to do it properly rather than just guessing his way through it.

HHD knows how to get the best out of the forum by offering up problems, his ideas of solutions, answering questions and giving feedback.

He could teach the majority of new posters a thing or 2 about forum etiquette!

 

[uksparks]

I always go for the hard sell and lots of pressure and scare mongering hen I see someone with a 3036 board... Just kidding, but do advise them thst lthough it works and is probably quite ok, things have changed somewhat and it could be significantly better.

I like HHD, nice bloke and always curtious on here and polite.

 

[davesparks]

Has the board ever experienced a fault in the past (black marks in the fuse carrier give it away)?

If it did then did the house burn down as a result or did it survive? Or did the board suffer any signs of damage (sometimes see a carbonised streak above the fuse carrier)

this will give you a clue as to its ability to handle faults

 

[HappyHippyDad]

Has the board ever experienced a fault in the past (black marks in the fuse carrier give it away)?

If it did then did the house burn down as a result or did it survive? Or did the board suffer any signs of damage (sometimes see a carbonised streak above the fuse carrier)

this will give you a clue as to its ability to handle faults

Thanks Dave,

There were no scorch marks in the fuse carriers, I checked all as I took them out. This would still only indicate that either there have been no faults that have caused the fuses to blow, or the carriers have been changed (unlikely).

I'd still be interested in the value/need for a breaking capacity on a fuse carrier if GN3 is suggested it could be classed as 16kA if all the above conditions are met?

Dillb has suggested he would put down 'Not verified' and code it 'accordingly'. Other sites have said they would put down 1kA as the breaking capacity as they would have to assume the lowest if it could not be verified. 'Not verified' is the obvious choice though as its the truth!

I think this is where lack of experience does show as I will base my decision on the regulations and guidance notes rather than the time served knowledge. I am at a loss to code this one and I do not mind admitting it!

I will purchase GN3, have a proper read and then most probably it will not be any code as the 16kA will taken into account.

 

[Deleted member 26818]

The 16kA is for Type tested CUs.
When fuses and MCBs are used in an untested enclosure, the rating on the side of the Fuse or MCB is then used.

 

[Lucien Nunes]

I would contact Wylex tech support for clarification. At least the company still exists unlike some old switchgear makers, so you should be able to get reliable info on both the rating and the type test status of the complete board. Let us know what you find, if you speak to them.

Worth noting that many of these boards were installed before routine testing of PFC. I have never seen one fail to break the circuit.

 

[Deleted member 26818]

It's not an indication of whether the devices will break a circuit.
It's an indication of the current that can be broken without damage to the equipment.

 

[Lucien Nunes]

My comment was just an aside that use of Wylex boards on supplies of typical PFC does not often seem to result in electrical apocalypse when a fault occurs. Nor do I recall seeing one that was destroyed by the fault current making it unfit for re-use.

In the case of an MCB the difference between Ics and Icu is not necessarily obvious to the user as the damage sustained is hidden inside, so you need to know from the figures that it won't be overstressed and remain in service in a damaged condition. At least with a BS3036 you can see if it is in a damaged condition because it will be in pieces!

 

[Deleted member 26818]

What I have never quite understood, is why a 3, 6 or even 10 kA device can be rated at 16kA when lumped together whith other devices in an enclosure, yet it is rated at the stated kA when installed singularly in a panel?

 

[happysteve]

What I have never quite understood, is why a 3, 6 or even 10 kA device can be rated at 16kA when lumped together whith other devices in an enclosure, yet it is rated at the stated kA when installed singularly in a panel?

It's because they give each other moral support. There's no I[SUB]cn[/SUB] in team.

 

[trev]

There's no I in team.

You know the stock answer to that hough don't you?

 

[happysteve]

I reckon I might know a word with a U in it, if that's what you're on about?

 

[Deleted member 26818]

Only the one word?

 

[happysteve]

Only the one word?

Sorry, yes. "Douchebag" is the only one I can think of. Perhaps as I get more experience on site I'll learn some others...?

Is this the sort of thing that's assessed on AM2?

 

[Risteard]

Annex ZA is a UK-only derogation. This gives the conditional rating (N.B. it is CONDITIONAL on, as spinlondon says, it being in a type-tested assembly etc.). I'm not sure why you would be uncomfortable with it - if the assembly meets the requirements for the conditional rating along with the upstream protection then it is entirely safe.

 

[Deleted member 26818]

Not a question of comfort, more a lack of understanding.
A device rated at 3kA is rated at 16kA when lumped together with other devices in an enclosure with quite limited space, whereas when placed in a panel with perhaps one or two other devices (sometimes none), with lots of space around, it is only rated at 3kA.

 

[HappyHippyDad]

Well... I contacted the Wylex helpline (01543 455000 - just in case anyone else wants it) and ALL wylex rewireable fuse holders are rated at 2kA.

The chap stated that the only one rated at 1kW was the 5A plug in MCB (with the 2 round push buttons on it).

He also stated that he is not aware of any rated at 4kW which was strange as they are clearly mentioned on some of the data sheets.

 

[Lucien Nunes]

Thanks for confirming this - I have also understood the breaking capacity to be 2kA and used that figure in the past, although not having an authoritative source I didn't mention it. The low Ics of the old Stotz pushbutton MCBs was par for the course in their day, which was a long time ago. I have a 5A example here and it is indeed rated M1.