KA RATING OF BS60898

[gram1980]

Risk of fire, had a couple which had become welded to the bus bar although not on fire, the whole busbar had to be changed.

Sent from my iPhone using Tapatalk

 

[binky]

the electrodes don't touch, the metal gas vapour from filament causes temporary short.

 

[Phoenix]

Worth pointing out that in domestic 6ka MCBs are usually fine. Aside from the fact that the impedance is only likely to be that low if the tx was in the garden of the house (I generally see figures of about 0.03 / 0.04 when testing at panelboards sat behind a wall from the 1Mva tx - admittedly thats likely higher than the actual figure as any poor contact with test probes at that level becomes significant...)

Anyway, BS EN 60439 - annex ZA requires consumer units to be able to withstand a fault level of 16ka when protected by a 100A BS1361 IIb cutout fuse (its important to note though, as its the assembly as a whole which is tested and approved... if you mix and match MCBs, then you then have an arrangement thats not been tested together and you loose that conditional 16ka fault rating.

Its not a modern thing either, it used to be in BS5486 part 13 ... so those old wylex re-wireable boards, you can't really comdemn them on account of measured fault levels in domestic!

 

[Doc Hudson]

I'll have to check and c if it is a recall .whats wrong with the recalls does anyone no thanks

There are some old threads on the recall MCB's, probably 18months to 2years since the problem was first raised. Have a search for Electrium recall MCB's

Doc H.

 

[wozz]

Anyway, BS EN 60439 - annex ZA requires consumer units to be able to withstand a fault level of 16ka when protected by a 100A BS1361 IIb cutout fuse (its important to note though, as its the assembly as a whole which is tested and approved... if you mix and match MCBs, then you then have an arrangement thats not been tested together and you loose that conditional 16ka fault rating.

a very good point

 

[PC Electrics]

Try a type C mcb as long as the Zs is in limits (which it probably will be in a normal house).

 

[butler26]

Thanks for the reply the tx is about 20meters away from the house so may be that's why Ze is so low

Well I'll check and see if it's a recall some time this week and go from there Once again thanks for all the help