mcb trip BS number help please

[dogwind]

Hi could anyone please tell me if the older push button style mcb's are noted on the test and inspection sheets as BS EN 60898 (b,c or d type) the same number as the newer style mcb's

Thanks

 

[TIGGERTOM13]

Usually the push button mcbs are BS3871 they will normally be types 1,2,3,4. The max disc times are different than bs en 60898. If they are type b,c,d then they will be 60898 and will have the same disconnection times

 

[telectrix]

the older push button ones which sometimes replaced 3036 fuses are bs3871. the later flick switch ones are bs60898

 

[dogwind]

Hi thanks for your quick reply, i will have to get my regs book out and look what difference the connection times are, i did look on one of the mcbs for any numbers like 60898 but they are quite old and faded, Cheers

 

[telectrix]

and the kA ratring od bs3871 is lower than bs60898, i think is 2kA or 3kA.

 

[TIGGERTOM13]

The KA rated is 3 forgot to mention that. BS3871 are not listed in current regs, if you can get a yellow 16th edition they are in there but you will have to calculate them for max disc times at 230V as they are calculated at 240

 

[Deleted member 26818]

Most probably not.
The older style MCBs were BS 3871, and were numbered Type 1, 2, 3 and 4.
The time characteristics for the old type are similar but not the same as for the new BS EN 60898 versions.
Type 1: 2.7 - 4 In, Type B: 3 - 5 In.
Type 2: 4 - 7 In, Type C: 5 - 10 In.
Type 3: 7 - 10 In, Type D: 10 - 20 In.
Type 4: 10 - 50 In.
During the change over of the standards, manufacturers were allowed to use the new BS EN 60898 designations on the old BS3871 devices, if they were within the limits specified.
For instance a Type 1 is within the specifications for Type B.
Types 2 and 3 are within the specifications for Type C.
However Type 4 is outside of the specifications for type D.
The 15th edition has time/current tables for BS3871 MCBs.
Many of the older BS3871 MCBs are only rated at a maximum of 1kA.
Most are rated at 3kA.
http://www.electriciansforums.net/a...ations-zs-values-older-protection-devices.pdf

 

[Silly Sausage]

Tiger,

Disconnection times are current dependant, the voltage is irrelevant.

An old thread...http://www.electriciansforums.net/i...ations/42745-time-curves-bs-3871-devices.html

 

[dogwind]

thanks again for your replies, i will note down the 3KA, as for the old 16th edition i think i have got one kicking around somewhere, its hard to keep up with all the regs i was told the other day i need a screwdriver with torque settings on it for doing up mcb's etc and it will also have to be calibrated every year, apparently a new reg coming out in january about it. Oh great fun more regs.

 

[TIGGERTOM13]

I think you would find the voltage relevant because the current (required to disconnect in the correct time) divided into the voltage give the max ZS values for the cpd. eg: 230/160A ( for a B32amp mcb)=1.44 ( the max ZS). When it was 240v you would get 240/160=1.5 the max ZS in the 16th. So the voltage is not irrelavent. If you get the old zs values divide them by 240 then multiply by 230 you will get the new values

 

[Engineer54]

I think you'll find that the values given in the 16th are the accurate values!! To the best of my knowledge, the UK is still being supplied with a 415/240 volt system... The new 400/230 volt band is a fictitious, paper or virtual voltage. A bloody stupid arrangement if you ask me, another example of ''Harmonisation NOT working to the UK's best interests. Or Europe come to that.... lol!!

 

[brspark]

The Figures for the BS3871' are in the on site guide listed with the 60898's .

 

[telectrix]

I think you'll find that the values given in the 16th are the accurate values!! To the best of my knowledge, the UK is still being supplied with a 415/240 volt system... The new 400/230 volt band is a fictitious, paper or virtual voltage. A bloody stupid arrangement if you ask me, another example of ''Harmonisation NOT working to the UK's best interests. Or Europe come to that.... lol!!

nothing done by mainland europe is in the UK's best interest. now they want more billions off us to subsidise the frogs, and the krauts are insisting we scrap the £.

 

[Engineer54]

I don't mind them Wanting, ....So long as they don't Get!!! The EU should have stopped at being a European common market. Common currency (Euro), and community laws that have nothing to do with the common market trade, as well as the European parliament is far too many steps too far, that no-one really wanted or needed!!!

 

[La Poste]

I think you'll find that the values given in the 16th are the accurate values!! To the best of my knowledge, the UK is still being supplied with a 415/240 volt system... The new 400/230 volt band is a fictitious, paper or virtual voltage. A bloody stupid arrangement if you ask me, another example of ''Harmonisation NOT working to the UK's best interests. Or Europe come to that.... lol!!

I seem to come across 235 Volts a lot these days, maybe that's what they mean by compromise, being half way between 230 Volts and 240 Volts.

As for the European Union, a cesspit of corruption if you ask me.