max zs

[jl-heating]

i have a bs 5419 type 1 sq D mcb and on my easycert the max Zs does not highlight any idea before i start geting my books out and screaming at the kids ...

cheers boys

 

[stani]

think BS5419 is an isolator not an MCB! so you wont get a zs

 

[jl-heating]

yes i thought so but on removing the mcb it had the same bs number on it ???

failing that sq D mcb type 1 anyone have the correct BS so can complete the cert .

 

[jl-heating]

think i sorted it .. SQUARE D 32A TYPE 1 MCB(3871)QO-E RANGE

does we all agree ??

 

[stani]

have a look at 26-02-2010 this question has appeared then , they said treat as a BS3871 type 1

 

[jl-heating]

ty mate .

 

[kme]

Would agree with that unit being a 3871 mate

 

[a1spark]

32A TYPE 1 MCB . -1.88 ohms. Max Zs/

a1 Spark

 

[Brian 157]

BS3871 MCBs haven't been listed in BS7671 for a while, they were in the 16th 3rd amendment. Prior to BS7671:2008 max Zs values were based on 240v (now calculated using 230v, hence being slightly different now). I recalculated the values using 230v and applied the GN 3 "rule of thumb" and got 1.43ohms for a maximum measured Zs.