fuses with a push button reset

YTSOxford · Mar 25, 2010

Hi, I remember at college I was told that if you see old resettable cartridge fuses (the ones where a button pops out) to replace them - but I can't remember the reasons why??? I just said that they no longer comply to my customer but what actually is the reason? I hate not knowing and talking rubish!

And anyone know the BS number of these so I can put it in the quote?

Cheers.

Jason Smith · Mar 25, 2010

Have a load on the van mate and will have you are your answer if no one lse can by tomorrow.
If you do change the box out, keep the button fuses, they plug into rewireable boards a treat for when you fault finding!!

DurhamSparky · Mar 25, 2010

yeah the Number is "BS OUT of DATE...."

not sure mate some bdy will pop up though

bs number of the new MCB flick switches is 60898

YTSOxford · Mar 25, 2010

DurhamSparky said:
yeah the Number is "BS OUT of DATE...."

not sure mate some bdy will pop up though

bs number of the new MCB flick switches is 60898

Yeah cheers mate, thats pretty much what I said to the bloke.

Notsosmart · Mar 25, 2010

I think you are talking about the old wylex MCB's (fuses are not resetable, once they have blown a new one is required) if so the bs number was; Bs3871 generally they only had a short circuit capacity of 1 or 2KA (M1 or M2)

DurhamSparky · Mar 25, 2010

quick google check show me that they are indeed BS3871 type 2

YTSOxford · Mar 25, 2010

Notsosmart said:
I think you are talking about the old wylex MCB's (fuses are not resetable, once they have blown a new one is required) if so the bs number was; Bs3871 generally they only had a short circuit capacity of 1 or 2KA (M1 or M2)

Cheers, I can't tell from the pictures if that is the breaker, but the small short circuit capacity is ringing a bell - so I think thats it.

pevvers · Mar 25, 2010

You lot are way too quick for my likings tonight...

Yep, 3871's. As far as I recall depending on the rating the breaking capacity was different. I think 5A were rated at 1 or 1.5kA, and the rest at 3 or 3.5kA, but it is clearly marked on the label or embossment (if there is such a word!) on the side....

Also, I seem to remember that there was a problem with the devices getting stuck closed due to the design.

ian.settle1 · Mar 26, 2010

Some fuses have a pop out but this is to indicate the fuse has blown not a reset.

MWE · Mar 26, 2010

Hi anybody tell me if old rewireable fuses and old bs3871's push button type and mcb's are all allowed within the same board (old wylex type)

pevvers · Mar 26, 2010

Yeah, I think he's talking about the old 3871 MCB's which have the little circular button on the front with a smaller circular button below to trip the device. As far as I recall, they had a tendancy to not trip when they needed to due to the little circular switch getting stuck behind the housing, but I could be talking out of my bum!

I've seen the fuses you're talking about I think, but you can also get the Red Spot ones which show when it's blown...

MWE said:
Hi anybody tell me if old rewireable fuses and old bs3871's push button type and mcb's are all allowed within the same board (old wylex type)

I can't think of any reason why they wouldn't be. 3871's do not strictly meet the current regulations, but are not dangerous. 3036's are still up to current regs, and any 60898's are also okay.

I think I would still suggest that they have a new board though, but on that basis I wouldn't be giving an unsatisfactory on a PIR unless they had non RCD sockets that are likely to supply portable equipment outside....

SirKit Breaker · Mar 26, 2010

Tell your customer to let you fit plug in 60898's. I have come across lots of these bloody things that dont trip, the button gets cacked up with crap and they jam in, they may trip under fault conditions but wont when you try to mechanically trip them...not good! so i wouldnt chance it dangerous in my mind. But as someone else has said keep the working ones for fault finding.

Cheers.............Howard

MWE · Mar 26, 2010

hi given customer both options of replacing either full cu or with 60898's but the same old same old thats how MUCH!!!! Just looking through ESC PIR best practice guide 4 relating to the issue and noticed the picture of the same scenario pictured. quoting "observations based solely on personal preference or 'custom and practice' should not be included. Think this answers my question. regards mwe.