Strip connectors in DBs

[sparx northeast]

Is there regulation that says connector blocks can not be used to join cables inside a DB?

 

[Geordie Spark]

Can they take 2x 0.75mm flexes?

Dunno about that but they make canny dust caps for your van's tyre valves.

 

[Plonker 3]

Sod paying for them, I just pinch them from someone else's van whole they are in the wholesalers.

 

[guest119]

Can they take 2x 0.75mm flexes?

No but they will take 3x036 or 7x029.

Boydy

 

[Darkwood]

Connectors - so yesterday - tacky and are a source of many electrical problems when used in DB's .. testing and additional circuits will move the conductors about and can loosen the joints.

Either wago style to be used both solid & stranded or insulated through crimps for stranded cable and uninsulated through crimps for solid drawn cable with heat shrink to insulate..

Each uses a different type of crimping tool suitable for the cable type ... Ill state again on this forum insulated crimps are not designed for solid drawn cables.

 

[pepparz]

Oh dear, most of the amigos on here like them as well.

 

[Darkwood]

Amount of times ive been challenged about crimping on solid with the phrase it passes the tug test... lol

Lets ignore the fact it deforms the crimps away from its designed method can overstretch the crimp even leaving weakened wall and cracks... but still pass this famous tug test .....lets see what over 1000amps fault current does to it .

Stranded cable under the crimp deforms the strands into the crimp shape giving a good crimp, solid cable doesn't deform as easy and ends up deforming the crimp instead giving a weakened joint... hence the solid crimping tools are very different to the ones used on stranded.

The only tug test they need to apply is probably in their own privacy alone :uhoh2:

 

[Engineer54]

Yep, and the amount of times i've contested those challenges too!! lol!!

Using a decent crimp and a decent crimping tool you'll not be having any problem when crimped correctly. All well and good using these so-called special crimps and crimping tools on military, aerospace and other higher than thou specs, especially where severe and/or continuous vibration are concerned, but in a typical building services type static environment, ...Nah!!

Having seen literally hundreds of thousands and more, of solid core conductors crimp terminated with just about every configuration of different crimps, from butt to ring crimps i've never seen a single failure due to conductor being solid, and that's the Truth!! Seen failures where crimp connections haven't been crimped correctly, but that goes for both solid and stranded conductors!!

As far as crimps being deformed, ...isn't that what's expected when say, using an indent type crimping tool?? In fact every crimped termination will deform the crimp that how they work, ...using the correct crimp tool for the crimp being used and you'll not go far wrong!!

What i will say is, that i don't like and never trusted the typical PVC insulated coloured crimps, and never have done. Always used good quality bare crimps with 2 layers of heat shrink tube, and more recently heat shrink insulated crimps. Other than that, i've No Problem crimping solid core cables as and where necessary, maybe taking a little extra care where vibration is a concern!!

 

[Darkwood]

As i said E54 failure may not rear its ugly head until a dead S/C ...which is why most get away with it and why critical industries ban them ... its not about their use under normal circumstances its about their use under fault conditions ... ive seen many a crimp on solid fail in my sector of the industry with inductive inrush although yes agree domestic not the biggest worry but shouldn't be an excuse to use them what we lack is solid guidelines hence the confusion ... we need the BS7671 to address this issue as it has had major consequences even if rare.

 

[Engineer54]

As i said E54 failure may not rear its ugly head until a dead S/C ...which is why most get away with it and why critical industries ban them ... its not about their use under normal circumstances its about their use under fault conditions ... ive seen many a crimp on solid fail in my sector of the industry with inductive inrush although yes agree domestic not the biggest worry but shouldn't be an excuse to use them what we lack is solid guidelines hence the confusion ... we need the BS7671 to address this issue as it has had major consequences even if rare.

Got to be honest, i've never seen a failure in any sector of the industry that i've worked in, none that could be put down to crimping solid cores as the problem. Been a long time since working in the industrial sector though, and maybe i could be persuaded that on some machinery, crimping on solid cores may be a source of potential future problems...

As far as typical building services type installations go, i can't see any problem in the use of solid core crimping, providing it's correctly performed with good quality crimps and crimping tools!!
What major consequences issues do you know about?? Pretty sure, if solid core crimp connections were causing concern within/across the industry, something positive would have been done about it by now. As for involving BS 7671 hell, that publication has trouble dealing with some of the basic issues, it'll not do too well with the do's and don'ts of crimping requirements, in fact they're best left well out of BS 7671!!

 

[GLENNSPARK]

well...i`m going to throw my two penneth in here:

as has been said a crimp deforms (the concept)...so if the crimping tool used supports the crimp all the way round during the crimping action then theres only one way left it can go really....isn`t there.....

 

[Darkwood]

Got to be honest, i've never seen a failure in any sector of the industry that i've worked in, none that could be put down to crimping solid cores as the problem. Been a long time since working in the industrial sector though, and maybe i could be persuaded that on some machinery, crimping on solid cores may be a source of potential future problems...

As far as typical building services type installations go, i can't see any problem in the use of solid core crimping, providing it's correctly performed with good quality crimps and crimping tools!!
What major consequences issues do you know about?? Pretty sure, if solid core crimp connections were causing concern within/across the industry, something positive would have been done about it by now. As for involving BS 7671 hell, that publication has trouble dealing with some of the basic issues, it'll not do too well with the do's and don'ts of crimping requirements, in fact they're best left well out of BS 7671!!

I'm possibly a stickler for correct procedures, as you have pointed out its not a big issue within our sector but using insulated crimps on solid core cable unless they are specifically designed to do so has been banned in many industries - more so those where sound clean connections are crucial and can risk lives if not done correctly... I've probably seen as many burnt out through crimps as i have standard connectors and both suffer a common problem of working loose if the cables in them are moved about... not an issue if correct crimps used.

Not a problem really most of the time it just turns a dirty brown/black colour and stinks of fish and is contained but where the likes of rail signalling, aviation, NASA some chemical industries etc these practices are completely banned for very good reason that they give a poor unreliable crimp and as i float between a few of these industries i often see it specified both crimp and crimper types to be used only (although Ive not had chance to work for NASA yet )

 

[Guest55]

storm in a tea cup to be honest.
and i've never had any connection problems with the thousands of solid core wires ive crimped , so in absence of any noticable evidence to the contrary , i'll continue.
saying that though , i use indent crimpers rather than compression crimpers which i find to make a better connection.
just because nasa wont do it building a space shuttle doesnt mean its not acceptable for the average joe to extend some t&e in a box..........

 

[DPG]

Check the manufacturer's technical data for the crimps being used. If they says they're suitable then they're suitable. Daz

 

[Guest111]

For what it's worth one of my ex's fathers worked in R&D at BICC on the crimp tools and terminals,now I remember him telling me that they .stipulated that their equipment was guaranteed fit for purpose if used like with like,I.E BICCON crimp tool with BICCON crimps,as although any red crimp may fit any crimper there may be an actual size difference leading to premature failure.this is why industries like Network Rail issue their staff with a particular crimper and matching crimps.I obtained some of the heat shrinkable crimps as used by NR and they would not crimp with my standard ratchet crimp tool.

 

[Engineer54]

I'm possibly a stickler for correct procedures, as you have pointed out its not a big issue within our sector but using insulated crimps on solid core cable unless they are specifically designed to do so has been banned in many industries - more so those where sound clean connections are crucial and can risk lives if not done correctly... I've probably seen as many burnt out through crimps as i have standard connectors and both suffer a common problem of working loose if the cables in them are moved about... not an issue if correct crimps used.

Not a problem really most of the time it just turns a dirty brown/black colour and stinks of fish and is contained but where the likes of rail signalling, aviation, NASA some chemical industries etc these practices are completely banned for very good reason that they give a poor unreliable crimp and as i float between a few of these industries i often see it specified both crimp and crimper types to be used only (although Ive not had chance to work for NASA yet )

Well you should always follow the specifications on any job or project, that's fair enough as far as i'm concerned. All down to commonsense at the end of the day, if you have a machine that is known to have a good deal of vibration or is always moving in it's working, then you use suitable alternative means of termination/connections etc... Other than that, i wouldn't say that correctly made solid core crimping give an unreliable connection, not from my experience anyway.

Again, as previously stated i don't like or trust the usual colour coded PVC insulated crimps, and never use them for any crimping operations.... We tend to use the colour coded XLPE heat shrink crimps, (that you can virtually see through) for the majority of our small conductors connections in panels and DB's, most of which on this project, are multi stranded anyway....