PIR codes, help please

[sjm]

Hi guys.
Just wanted to ask what code you would give an old wylex fuse board with wooden enclosure. It does have the plastic (plexolin I think it's called) plate at the back.
Also 2.5 T+E with 1.0mm CPC used for a ring main on a 3036 fuse.

Thanks in advance.
Steve

 

[telectrix]

code 2 for the board. code 4 for the 1.0mm cpc IMO.

 

[tonys]

Ill go with Tel for once lol

 

[somersetsparks]

Hi mate, 2.5mm with 1.0 earth is fine as long as all test results are o.k.
Wooden back wylex board - not sure, as long as all loads are not over 60A with diversity then they are o.K from a PSCC point of view as the DNO fuse covers this with its 16.5KA rating. They comlied when they were installed, It has been modified with a paxolin back, hmm difficult. I think they don't comply now due to ignitability, which is somewere in that red book. I would possibly code 2 if there was signs of damage and burning, or in your case I would probably code 4 - complies to previous edition.

oh p.s. its Paxolin ;-)

 

[sjm]

Thanks guys, pretty much what I thought, but it's always nice to get a 2nd opinion.

 

[telectrix]

just like millionaire. ask the audience, yes that's what i thought . only joking steve!

 

[sjm]

It' better than 50/50 though and at least I've still got phone a friend left, lol.

 

[Guest123]

Well I'll have my 10p now then.

IMO a 2.5/1.0 ring final on a BS 3036 fuse is a code 2 as it fails the adiabatic equation for this type of fuse.

The board itself I'd have no problems with, the lack of RCD protection possibly, depending on circumstances.

 

[telectrix]

IMO a 2.5/1.0 ring final on a BS 3036 fuse is a code 2 as it fails the adiabatic equation for this type of fuse.


could this not depend on the length of the ring, and comply if the ring was short enough for the 1.omm cpc to be adequate?

 

[tonys]

Very subjective are pir codes lol

 

[somersetsparks]

You are indeed right lenny adiabiatic comes out at 1.15 I think, however someone on our lot phoned the IET about it a couple of years ago as a result of an argument like this and was told that it was OK if it met the rwquired results, in their opinion...

Suppose its all down to interpretation again.

 

[Deleted member 26818]

Well I'll have my 10p now then.

IMO a 2.5/1.0 ring final on a BS 3036 fuse is a code 2 as it fails the adiabatic equation for this type of fuse.

The board itself I'd have no problems with, the lack of RCD protection possibly, depending on circumstances.

What value for k are you using?

 

[nickblake]

If its missing its spark cover then its a code 1 code 2 if its in place

 

[telectrix]

If its missing its spark cover then its a code 1 code 2 if its in place[/QUOT

and what's the code for 2" nails in the fuse holders. minus???

 

[tony mc]

I think he would of used k 115 and 210 A with a 0.4 sec dis.I think.

 

[Deleted member 26818]

115 is for a conductor with an initial temperature of 70ºC or greater.
I'd be more inclined to use 143.

 

[Guest123]

TBH there are so many different factors that could influence the outcome it's difficult to stamp an assured answer one way or t'other.

I calculate to 1.15 (spot on somerset ) ergo a 1.0mm cpc is insufficient to withstand the fault current for the given time.

All IMO.

 

[nickblake]

If its missing its spark cover then its a code 1 code 2 if its in place[/QUOT

and what's the code for 2" nails in the fuse holders. minus???

nothing wrong with a nail in the fuse holder eliminates neusance tripping code 1 i think , i hate rewireable fuses they should be banned so easy for mis use and electric shock every time you take the fuse carrier out you expose live busbars , yes i know the should switch it off when the do it but its the general public we are talking about and 80% just pull out the fuse its a miricle people havent been killed with them or perhaps they have

 

[telectrix]

looks like your'e returning to your normal self, nick.

 

[Deleted member 26818]

TBH there are so many different factors that could influence the outcome it's difficult to stamp an assured answer one way or t'other.

I calculate to 1.15 (spot on somerset ) ergo a 1.0mm cpc is insufficient to withstand the fault current for the given time.

All IMO.

Is 115 for k an appropriate value to use, considering the conductor is unlikely to initially be at 70ºC or greater?