BS 3871 Push Button Circuit Breakers

[Theorysparky]

Reading the NIC Periodic Inspection and testing book it mentions about these breakers (annex f)

are these to be replaced en mass or only if they do not meet the required Zs values ???

the ones that that are outside the max Zs i have put as code 2 but what about the others ?????

 

[SLIPSHOD & SLAPDASH]

Its not the breakers that are outside the max Zs, its the circuit !

 

[Theorysparky]

i understand that the breaker needs to be changed on that circuit to comply

but are the others ok to leave if they are within speck ?? thats what im asking

 

[Sidewinder]

Theo,

Not only the Zs bit, but also the PFC may be more than the CB can cope with depending on the supply configuration Ze values etc.

 

[Evans Electric]

Theo , if you mean the Wylex Plug-in ones , I think we are supposed to replace them due to their 1K rating or whatever it is .

 

[Andy™]

Theo , if you mean the Wylex Plug-in ones , I think we are supposed to replace them due to their 1K rating or whatever it is .

yet 3036's are often 1KA.....

you dont need to change them.

 

[PC Electrics]

No specific requirement to change them, but if Zs is too high you could change to the plug in 60898 type at an appropriate rating for the Zs. If you've got to change several, would it be a bridge too far to change them all?

 

[Theorysparky]

No specific requirement to change them, but if Zs is too high you could change to the plug in 60898 type at an appropriate rating for the Zs. If you've got to change several, would it be a bridge too far to change them all?

Thats what i thought

i have enough assortment kicking around to sort it

 

[muffin]

bs3036 fuses are as followed

2ka 5-30amp type sa2

4ka 30+ type sa4

the push button bs3871 mcbs are/maybe rated at 1ka and they only need to be changed if your ka exceeds this, there is nothing wrong with them apart from they dont always reset and you have to tap them to get the trip button to come back out.

regards andy

 

[Theorysparky]

Thanks for that Andy

 

[professional]

Theo , if you mean the Wylex Plug-in ones , I think we are supposed to replace them due to their 1K rating or whatever it is .

I believe they were rated at 3kA.

 

[Andy™]

had a quick look at some spares i have

3871 push type - M2

3871 & 60898 toggle - M3

 

[Megaohm7]

bs3036 fuses are as followed2ka 5-30amp type sa2

4ka 30+ type sa4

the push button bs3871 mcbs are/maybe rated at 1ka and they only need to be changed if your ka exceeds this, there is nothing wrong with them apart from they dont always reset and you have to tap them to get the trip button to come back out.

regards andy

At a property today where I was trying to identify a circuit to isolate and the board didn't have any labelling on it at all.The CPD's were BS3871 and I had trouble getting one to reset. I'm just glad that that I found the correct breaker on the 3rd attempt!! I did ask when the install was last checked and the client said We have been here for over 30yrs and nothing as been done in that time. I did suggest a periodic inspection but their answer was that it's been ok all those years so why bother..I said no RCD protection for starters..You cant force people can you ?

 

[Theorysparky]

Mega

No RCD protection is not a reason to do a cu upgrade,,,,, a plug in unit is fine for outdoor power use

 

[Megaohm7]

MegaNo RCD protection is not a reason to do a cu upgrade,,,,, a plug in unit is fine for outdoor power use

Hi Theorysparky..I Know what your saying but I was suggesting an Inspection and test on the install as you do notice things that don't look great !! But you can only advise.

 

[Theorysparky]

Hi Theorysparky..I Know what your saying but I was suggesting an Inspection and test on the install as you do notice things that don't look great !! But you can only advise.

Fair one.....

 

[Brian 157]

I was under the impression that the push-button plug-in MCBs to BS3871 pre date the type numbers (1, 2, 3 & 4) so are deamed to be type 4 with a fusing factor of up to 50, so in most cases won't meet the required disconnection times, I may be wrong but I'm sure I got that from the ECA or NICEIC back in the distant past...

 

[SLIPSHOD & SLAPDASH]

I was under the impression that the push-button plug-in MCBs to BS3871 pre date the type numbers (1, 2, 3 & 4) so are deamed to be type 4 with a fusing factor of up to 50, so in most cases won't meet the required disconnection times, I may be wrong but I'm sure I got that from the ECA or NICEIC back in the distant past...

No , i dont think so. Andy was correct earlier. I assume everyone is talking about Wylex here, but remember MEM also made push button MCB's

 

[kme]

Concur with SlipSlap on that mate.....

 

[Voltimax]

Getting back to the ratings of those Wylex plug in MCB's.

GE manufacture a 60898 6kA version. The wylex 60898 themselves are 3kA.