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| UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions. |
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#41
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In article ,
Andrew Mawson wrote: Crimps used in low voltage applications where high humidity is expected (external joint boxes for telephones for instance) are filled with a vaseline like anti-oxidant water repellant. As are most multi-pin connectors found on cars in recent years. However, on my old Rover SD1, they didn't include the crimps from the harness to the said multi-pin connectors, and some have gone high resistance. Wonder if the cable and connector had been coated in tin, etc, rather than plain copper and plain brass would have extended their 'life'? -- *I have a degree in liberal arts -- do you want fries with that Dave Plowman London SW To e-mail, change noise into sound. |
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#42
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In article ,
"Andy Luckman (AJL Electronics)" writes: In article , John_ZIZinvalid wrote: Yes. Keep within the ring where possible, and don't cross connect between both legs, this is better explained in the IEE On-Site guide with the aid of diagrams. Yes, that's fully understood, to keep the ring intact. I was going to parallel the earths though. I suppose not any good reason to, as long as one of them connects to the back box. The regs certainly allow for the earths of a ring to have a different topology than the live conductors in some cases, e.g. when provided by steel conduit or by the mineral insulation copper cover. I'd have to delve into the regs to see if that only applies in these cases. Generally cross connecting CPC's can only result in improvement to the earth fault loop impedance, and it is required in certain places, e.g. in all the circuits used in a bath/shower room. -- Andrew Gabriel |
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#43
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On Tue, 14 Jun 2005 11:40:51 +0100, "Dave Plowman (News)"
wrote: Wonder if the cable and connector had been coated in tin, etc, rather than plain copper and plain brass would have extended their 'life'? No, they suffer more from galvanic corrosion between them than you save from reduced oxidation. In the car context, plated terminals are less troublesome for their life, then fail. Plain brass are a higher resistance for most of it, but their usable "life" is longer. |
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#44
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On Tue, 14 Jun 2005 11:15:41 +0100, David Hearn
wrote: it also means that the area of contact (and therefore electrical conduction) is smaller meaning it heats up. It's a thin layer. So although the resistivity/length is indeed high, the actual resistance added is negligible. Only if you start getting a loose connection where the area drops down to a fraction of a screw area do you start to see appreciable heating. |
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#45
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On Tue, 14 Jun 2005 10:06:09 +0100, antgel
wrote: Ok. I've read enough of this thread to feel nervous. I have crimped some 1.5T&E with some blue crimps and a ratchet crimping tool. If these crimps are not correct for the job, can someone point me to some that are? I have never heard of mains-rated crimps. Hi, I'd not worry about now it unless they're taking a lot of current and/or near anything flammable, or the wires might get moved or disturbed or have flammable stuff placed near them. Often a safe and lasting 'bodge' is very acceptable  Though if I was a tradesperson I'd find another way of joining the cable or some use crimps designed for solid core. What do the IEE make of using 'auto' crimps? Maybe this has been discussed on their forum. I'd expect if everyone started using ones designed for solid core the prices would come down. cheers, Pete. |
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#46
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In article ,
Andy Dingley wrote: Wonder if the cable and connector had been coated in tin, etc, rather than plain copper and plain brass would have extended their 'life'? No, they suffer more from galvanic corrosion between them than you save from reduced oxidation. In the car context, plated terminals are less troublesome for their life, then fail. Plain brass are a higher resistance for most of it, but their usable "life" is longer. Excellent, thanks. I'm sure we could get an answer to the meaning of life here. -- *Am I ambivalent? Well, yes and no. Dave Plowman London SW To e-mail, change noise into sound. |
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#47
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In article ,
Pete C wrote: What do the IEE make of using 'auto' crimps? Maybe this has been discussed on their forum. I'd expect if everyone started using ones designed for solid core the prices would come down. As I said, the pre-insulated types sold by TLC and others as presumably for mains use appear no different from the ones sold by Halfords presumably for auto use. -- *I don't know what your problem is, but I'll bet it's hard to pronounce Dave Plowman London SW To e-mail, change noise into sound. |
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#48
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Andrew Mawson wrote:
I was taught that a properly made crimp is actually a gas tight joint at the points of contact, so if the wires were acceptably free of oxide when crimped, they should remain so.(This is apparently true also of a 'wire wrapped' joint previously used in telecoms and early computers, where a wire is tightly wrapped round a square post to make a connection.) There's a kind of spot welding going on there. If you unwrap one of those joints you have to tear the wire away from the post at each corner. |
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#49
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On Tue, 14 Jun 2005 15:53:30 +0100, "Dave Plowman (News)"
wrote: In article , Pete C wrote: What do the IEE make of using 'auto' crimps? Maybe this has been discussed on their forum. I'd expect if everyone started using ones designed for solid core the prices would come down. As I said, the pre-insulated types sold by TLC and others as presumably for mains use appear no different from the ones sold by Halfords presumably for auto use. Hi, They may be fine for mains use but a lot of people assume that includes solid core T&E, and I expect they're only intended for stranded mains cable, eg conduit cable. If you look up some tech info on these on the RS site they all talk about use with stranded cable and not solid core. Even so if I was a tradesperson I'd even buy branded ones for use with stranded mains cable, saving a few pennies by using unbranded ones isn't worth the risk. cheers, Pete. |
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#50
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Pete C wrote:
On Tue, 14 Jun 2005 15:53:30 +0100, "Dave Plowman (News)" wrote: In article , Pete C wrote: What do the IEE make of using 'auto' crimps? Maybe this has been discussed on their forum. I'd expect if everyone started using ones designed for solid core the prices would come down. As I said, the pre-insulated types sold by TLC and others as presumably for mains use appear no different from the ones sold by Halfords presumably for auto use. Hi, They may be fine for mains use but a lot of people assume that includes solid core T&E, and I expect they're only intended for stranded mains cable, eg conduit cable. If you look up some tech info on these on the RS site they all talk about use with stranded cable and not solid core. Even so if I was a tradesperson I'd even buy branded ones for use with stranded mains cable, saving a few pennies by using unbranded ones isn't worth the risk. cheers, Pete. Not sure which ones you're looking at on RS, but the ones I've seen say that they are suited for solid or stranded wires. Specifically - part code 842-107 ("Plasti-Grip Butt Splice Terminals" - I looked at the blue one!). Click on the Tech Info button. Then select the "General info on Plasti-Grip" link. When the PDF opens, look at the bottom of the page - and you'll see that it's certified as UL Listed for "Terminals, Butt & Parallel Splices XX-YY Solid or Stranded" with a note saying that Standed wire is only supported when using "Tetra-Crimp tooling". D |
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#51
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On Tue, 14 Jun 2005 20:03:10 +0100, David Hearn
wrote: Not sure which ones you're looking at on RS, but the ones I've seen say that they are suited for solid or stranded wires. Specifically - part code 842-107 ("Plasti-Grip Butt Splice Terminals" - I looked at the blue one!). Click on the Tech Info button. Then select the "General info on Plasti-Grip" link. When the PDF opens, look at the bottom of the page - and you'll see that it's certified as UL Listed for "Terminals, Butt & Parallel Splices XX-YY Solid or Stranded" with a note saying that Standed wire is only supported when using "Tetra-Crimp tooling". Sounds good! I take back what I said earlier then. Hopefully an inexpensive rachet crimper would be just as good as the recommended tool  But the UL test for pullout doesn't look that hard to meet: http://catalog.tycoelectronics.com/TE/bin/TE.Connect?C=123&F=0&M=CINF&GIID=123&LG=1&I=13&RQS =C~123^M~FEAT^G~G I'd still avoid the most cheapo terminals and crimpers though. cheers, Pete. |
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#52
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Pete C wrote:
On Tue, 14 Jun 2005 15:53:30 +0100, "Dave Plowman (News)" wrote: In article , Pete C wrote: What do the IEE make of using 'auto' crimps? Maybe this has been discussed on their forum. I'd expect if everyone started using ones designed for solid core the prices would come down. As I said, the pre-insulated types sold by TLC and others as presumably for mains use appear no different from the ones sold by Halfords presumably for auto use. Hi, They may be fine for mains use but a lot of people assume that includes solid core T&E, and I expect they're only intended for stranded mains cable, eg conduit cable. I still see no reason why it should make any difference. Why should a crimp 'designed for stranded cable' work any less well on solid? -- Chris Green |
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#53
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#55
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In article ,
tony sayer wrote: FWIW we've used crimps on vehicle installations for many years with no problems at all. However it seems to me that an awful lot is down the crimps used, and even more the what you use to crimp them. The only really good crimped joints are those that are done with the heavy duty ratchet type crimpers. The ones that work with a simple "scissor" action as it were, aren't that clever. Some of the crimps on the factory loom on my 20 year old Rover are giving trouble. They've gone high resistance. BTW, my rather expensive crimping tool for Lucar non insulated connectors isn't a ratchet type - merely cantilever. -- *Shin: a device for finding furniture in the dark * Dave Plowman London SW To e-mail, change noise into sound. |
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#56
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On Wed, 15 Jun 2005 12:41:56 +0100, tony sayer
wrote: The ones that work with a simple "scissor" action as it were, aren't that clever. I agree the [insert name of cheap DIY emporium] type of scissor action crimpers, however, I am most impressed with the pair of AMP branded crimpers I obtained, they are scissor action, but relatively long handles and very short 'crimping arms' make for very high pressure, and they're thicker stock than the usual, [circa 1/6 of an inch] with very well shaped work areas, thus crimping MUCH better on both insulated and non-insulated terminals. -- "The most overlooked advantage of owning a computer is that if they foul up there's no law against whacking them around a bit." - Eric Porterfield. |
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#57
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In article , Dave Plowman (News)
writes In article , tony sayer wrote: FWIW we've used crimps on vehicle installations for many years with no problems at all. However it seems to me that an awful lot is down the crimps used, and even more the what you use to crimp them. The only really good crimped joints are those that are done with the heavy duty ratchet type crimpers. The ones that work with a simple "scissor" action as it were, aren't that clever. Some of the crimps on the factory loom on my 20 year old Rover are giving trouble. They've gone high resistance. Amazing its still on the road with it being a Rover  )BTW, my rather expensive crimping tool for Lucar non insulated connectors isn't a ratchet type - merely cantilever. Well ours cost around 30 odd quid, but they do the job very well indeed )-- Tony Sayer |
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#58
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Pete C wrote:
AMP also market their 'solistrand' type crimps, if the plastic insulated ones were just as reliable would there be a need for another type? : You have a good point; but detailed reading of the AMP datasheets both at the rswww.com site and at AMP/Tyco's own site reveal claims that their Plasti-grip and PIDG ranges are designed for solid as well as stranded wire. However, AMP's tooling isn't exactly cheap - if you buy it fullprice (at rswww.com, for example) you're looking at a hundred notes for the cheaper flavour, and 250 for the certified one! Much other documentation on crimps is all around their use on *stranded* wires, and that's the overwhelmingly common case in practice. I tend to agree with you - random crimpology using bargain-bin crimps and a plier-style tool is not what I'd call 'good workmanship'; and I generally prefer to have cable connections genuinely accessible, and would rather replace a run with a new piece than join two ends somewhere out of sight... Stefek |
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#59
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On Wed, 15 Jun 2005 19:39:02 +0100, Stefek Zaba
wrote: However, AMP's tooling isn't exactly cheap If you want _really_ expensive, look at the tools with on-board load cells and data loggers. Last few times I've been to Bideford it was to get to Lundy, not to work at AMP, but they used to have a fair few machines on that site running some of my code - both crimpers, and the press tools that made the crimps. Ah, real-time data loggers under DOS - now there's a pointless stick to beat yourself with. Rewriting the font generator to get analogue graphics out of a text-mode colour display too - it was like coding on a damned Spectrum! |
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#60
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Andy Dingley wrote:
However, AMP's tooling isn't exactly cheap If you want _really_ expensive, look at the tools with on-board load cells and data loggers. Yes - I was only covering hand tooling, not the bench-installed MIL-STD-traceable gubbins! Ah, real-time data loggers under DOS - now there's a pointless stick to beat yourself with. At least under DOS you're close to the bare metal, and can lock out interrupts reliably. Try doing that with Windows ;-) Rewriting the font generator to get analogue graphics out of a text-mode colour display too - it was like coding on a damned Spectrum! or, indeed, the geeks who combined two separate video modes on the Elite screen to run the upper three-quarters in a hi-res monochrome mode and the status-display in lower-res more-colours mode. And you tell that to the DirectX9 games writers of today, with their Z buffers and anisotropic shaders and multiple pipelines, and they won't believe you... |
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#61
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In article ,
tony sayer wrote: Some of the crimps on the factory loom on my 20 year old Rover are giving trouble. They've gone high resistance. Amazing its still on the road with it being a Rover )Well, I look after it myself. ;-) It's a late SD1 I've had from near new - and despite never being garaged is near enough rust free. They'd found wax by that time. ;-) It's not my daily driver now, but kept, because of apart being fun to drive, is as big as many estate cars when the rear seats folded down, etc, so useful for collecting DIY materials. My main car, a BMW, is useless in this respect. BTW, my rather expensive crimping tool for Lucar non insulated connectors isn't a ratchet type - merely cantilever. Well ours cost around 30 odd quid, but they do the job very well indeed )Mine was near twice that price from Vehicle Wiring Products. Where did yours come from? -- *Despite the cost of living, have you noticed how it remains so popular? Dave Plowman London SW To e-mail, change noise into sound. |
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#62
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In article , Dave Plowman (News)
writes In article , tony sayer wrote: Some of the crimps on the factory loom on my 20 year old Rover are giving trouble. They've gone high resistance. Amazing its still on the road with it being a Rover )Well, I look after it myself. ;-) It's a late SD1 I've had from near new - and despite never being garaged is near enough rust free. They'd found wax by that time. ;-) It's not my daily driver now, but kept, because of apart being fun to drive, is as big as many estate cars when the rear seats folded down, etc, so useful for collecting DIY materials. My main car, a BMW, is useless in this respect. BTW, my rather expensive crimping tool for Lucar non insulated connectors isn't a ratchet type - merely cantilever. Well ours cost around 30 odd quid, but they do the job very well indeed )Mine was near twice that price from Vehicle Wiring Products. Where did yours come from? Ken Godwin sales, he does bits for mobile radio installers but we don't use him anymore, we contract that out... http://www.ken-godwin.com/product_in...roducts_id=424 seems the price has dropped quite a bit since we bought ours but they do exert a lorra force on the crimp -- Tony Sayer |
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#63
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In article ,
tony sayer wrote: BTW, my rather expensive crimping tool for Lucar non insulated connectors isn't a ratchet type - merely cantilever. Well ours cost around 30 odd quid, but they do the job very well indeed )Mine was near twice that price from Vehicle Wiring Products. Where did yours come from? Ken Godwin sales, he does bits for mobile radio installers but we don't use him anymore, we contract that out... http://www.ken-godwin.com/product_in...roducts_id=424 seems the price has dropped quite a bit since we bought ours but they do exert a lorra force on the crimp Ah - but that's a crimp for standard red blue and yellow terminals that you'll find in any toolshop or electrical wholesaler. Mine is the PR3 one on this page http://www.vehicle-wiring-products.co.uk/VWPweb2000/terms-non2/terms-non2.html It's for non insulated terminals. -- *For every action, there is an equal and opposite criticism * Dave Plowman London SW To e-mail, change noise into sound. |
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#64
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In article , Dave Plowman (News)
writes In article , tony sayer wrote: BTW, my rather expensive crimping tool for Lucar non insulated connectors isn't a ratchet type - merely cantilever. Well ours cost around 30 odd quid, but they do the job very well indeed )Mine was near twice that price from Vehicle Wiring Products. Where did yours come from? Ken Godwin sales, he does bits for mobile radio installers but we don't use him anymore, we contract that out... http://www.ken-godwin.com/product_in...roducts_id=424 seems the price has dropped quite a bit since we bought ours but they do exert a lorra force on the crimp Ah - but that's a crimp for standard red blue and yellow terminals that you'll find in any toolshop or electrical wholesaler. Mine is the PR3 one on this page http://www.vehicle-wiring-products.co.uk/VWPweb2000/terms-non2/terms-non2.html It's for non insulated terminals. Yes thats the one we used to use before we used the other type..... -- Tony Sayer |
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#65
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In article ,
tony sayer wrote: Ah - but that's a crimp for standard red blue and yellow terminals that you'll find in any toolshop or electrical wholesaler. Mine is the PR3 one on this page http://www.vehicle-wiring-products.co.uk/VWPweb2000/terms-non2/terms-non2.html It's for non insulated terminals. Yes thats the one we used to use before we used the other type..... Sorry to say it, but pre-insulated terminals on a car look like a bodge. And in fact are. They might be ok for very low current use, but in fact aren't actually correctly designed for the common car cable sizes. IMHO. And then they look just plain wrong, as they never appeared on maker's looms. Of course this doesn't matter for the aftermarket bodge in an alarm, etc, trade. ;-) Using the correct non insulated Lucar connectors with separate covers and this crimping tool I get results I defy you to tell from the OEM wiring. Oh - and they work rather better. You'll often find a pre-insulated red connector will pull off 32/0.20mm rather easily - since that connector is meant for 1.5mm wiring. And 32/0.20 is nearer 1mm. A properly crimped non insulated type will damage the wire if pulled off. -- *Procrastinate now Dave Plowman London SW To e-mail, change noise into sound. |
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#66
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On Thu, 16 Jun 2005 12:36:44 +0100, "Dave Plowman (News)"
wrote: Sorry to say it, but pre-insulated terminals on a car look like a bodge. And in fact are. They might be ok for very low current use, but in fact aren't actually correctly designed for the common car cable sizes. IMHO. And then they look just plain wrong, as they never appeared on maker's looms. Of course this doesn't matter for the aftermarket bodge in an alarm, etc, trade. ;-) Using the correct non insulated Lucar connectors with separate covers and this crimping tool I get results I defy you to tell from the OEM wiring. Oh - and they work rather better. You'll often find a pre-insulated red connector will pull off 32/0.20mm rather easily - since that connector is meant for 1.5mm wiring. And 32/0.20 is nearer 1mm. A properly crimped non insulated type will damage the wire if pulled off. I use 32/02 but double the strands over to give 2mm and use a blue crimp and ratchet crimper. A blade/receptacle connection using this method will pull apart way before the crimp can be pulled off the wire. I'd agree that the uninsulated crimps are better, lack of round tuits is holding me back here... cheers, Pete. |
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#67
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In article , Dave Plowman (News)
writes In article , tony sayer wrote: Ah - but that's a crimp for standard red blue and yellow terminals that you'll find in any toolshop or electrical wholesaler. Mine is the PR3 one on this page http://www.vehicle-wiring-products.c...ms-non2/terms- non2.html It's for non insulated terminals. Yes thats the one we used to use before we used the other type..... Sorry to say it, but pre-insulated terminals on a car look like a bodge. And in fact are. They might be ok for very low current use, but in fact aren't actually correctly designed for the common car cable sizes. IMHO. What do they use on modern motahs, cant say I've ever had to sod about with the wiring on my Audi to notice.... And then they look just plain wrong, as they never appeared on maker's looms. Of course this doesn't matter for the aftermarket bodge in an alarm, etc, trade. ;-) Should hope not, as a lot of wiring in that instance is floating to some extent.. Using the correct non insulated Lucar connectors with separate covers and this crimping tool I get results I defy you to tell from the OEM wiring. Whatever Oh - and they work rather better. Really, just how?.. You'll often find a pre-insulated red connector will pull off 32/0.20mm rather easily - since that connector is meant for 1.5mm wiring. And 32/0.20 is nearer 1mm. Don't have that problem.. A properly crimped non insulated type will damage the wire if pulled off. So will these buggers. They almost do a cold weld and in umpteen years we've never had a failure yet. Drop me your snail mail addy and I'll send you a few examples!.. -- Tony Sayer |
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#68
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In article ,
Pete C wrote: I use 32/02 but double the strands over to give 2mm and use a blue crimp and ratchet crimper. A blade/receptacle connection using this method will pull apart way before the crimp can be pulled off the wire. Yes - it's slightly better, but of course blue is really meant for 2.5mm. I'd agree that the uninsulated crimps are better, lack of round tuits is holding me back here... It's simply I've done lots of this sort of thing and found out it was the best option. For one offs, soldering a standard lucar connector after crimping the conductor part with pliers, then letting it cool, and then crimping the insulation gripping part is probably the best DIY cost effective route, but then soldering in situ can be a PITA. -- *I have my own little world - but it's OK...they know me here* Dave Plowman London SW To e-mail, change noise into sound. |
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#69
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In article ,
tony sayer wrote: Sorry to say it, but pre-insulated terminals on a car look like a bodge. And in fact are. They might be ok for very low current use, but in fact aren't actually correctly designed for the common car cable sizes. IMHO. What do they use on modern motahs, cant say I've ever had to sod about with the wiring on my Audi to notice.... Nor on my E60. But we're talking older or more basic cars where aftermarket accessories may be fitted? And then they look just plain wrong, as they never appeared on maker's looms. Of course this doesn't matter for the aftermarket bodge in an alarm, etc, trade. ;-) Should hope not, as a lot of wiring in that instance is floating to some extent.. Using the correct non insulated Lucar connectors with separate covers and this crimping tool I get results I defy you to tell from the OEM wiring. Whatever Oh - and they work rather better. Really, just how?.. You'll often find a pre-insulated red connector will pull off 32/0.20mm rather easily - since that connector is meant for 1.5mm wiring. And 32/0.20 is nearer 1mm. Don't have that problem.. Try it some time. And I've often seen 'pro' installations with bare wire sticking out beyond the insulation. Which you'd have to be very clumsy to do with the correct connector and sleeve. A properly crimped non insulated type will damage the wire if pulled off. So will these buggers. They almost do a cold weld and in umpteen years we've never had a failure yet. Drop me your snail mail addy and I'll send you a few examples!.. You won't get a cold weld with RBY pre-insulated types on car wiring. Not one standard car wire size is close enough for that. I'm not denying they might work well enough. For a while. ;-) -- *Frankly, scallop, I don't give a clam Dave Plowman London SW To e-mail, change noise into sound. |
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#70
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In article , Dave Plowman (News)
writes In article , tony sayer wrote: Sorry to say it, but pre-insulated terminals on a car look like a bodge. And in fact are. They might be ok for very low current use, but in fact aren't actually correctly designed for the common car cable sizes. IMHO. What do they use on modern motahs, cant say I've ever had to sod about with the wiring on my Audi to notice.... Nor on my E60. But we're talking older or more basic cars where aftermarket accessories may be fitted? And then they look just plain wrong, as they never appeared on maker's looms. Of course this doesn't matter for the aftermarket bodge in an alarm, etc, trade. ;-) Should hope not, as a lot of wiring in that instance is floating to some extent.. Using the correct non insulated Lucar connectors with separate covers and this crimping tool I get results I defy you to tell from the OEM wiring. Whatever Oh - and they work rather better. Really, just how?.. You'll often find a pre-insulated red connector will pull off 32/0.20mm rather easily - since that connector is meant for 1.5mm wiring. And 32/0.20 is nearer 1mm. Don't have that problem.. Try it some time. And I've often seen 'pro' installations with bare wire sticking out beyond the insulation. Which you'd have to be very clumsy to do with the correct connector and sleeve. A properly crimped non insulated type will damage the wire if pulled off. So will these buggers. They almost do a cold weld and in umpteen years we've never had a failure yet. Drop me your snail mail addy and I'll send you a few examples!.. You won't get a cold weld with RBY pre-insulated types on car wiring. Not one standard car wire size is close enough for that. I'm not denying they might work well enough. For a while. ;-) ......Whatever..... -- Tony Sayer |
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#71
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[Thread resurrection]
I have previously been an advocate of crimping mains cables, both solid and stranded, provided the correct tool is used. Now I need to add to that. Do NOT trust the insulated crimps from unknown manufacturers, as supplied by many otherwise excellent electrical wholesalers until you have taken one from the pack, and snipped off the plastic to see that it is adequate (preferably after purchase g ). I found some today that had an excessive amount of the metal in the middle section removed, by my guesstimation, down to maybe 2.0 sq mm, or maybe less, and very soft squishy copper at that. Being that these crimps are rated for 12 AWG wire which is around 3.06 sq mm CSA, I consider this a dangerous defect. Fortunately I was warned by the fact that my Amp crimp tool just crimped them as if they were mere plastic, indeed, one broke in the middle, with the plastic holding the broken parts in place. A severe potential fire risk there, that would not have been caused by the usual suspects with crimps [poor crimping] but by what I consider to be a manufacturing defect. Suffice to say, strip connector got used instead, thank $DEITY I found it before energizing the 32 amp circuit they were on. Hope this forewarns someone and saves someone losing everything. -- "Anyone who is capable of getting themselves made President should on *no* account be allowed to do the job." - The Hitchhiker's Guide to the Galaxy |
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#72
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On Thu, 23 Jun 2005 22:14:42 GMT, Chip
wrote: [Thread resurrection] I have previously been an advocate of crimping mains cables, both solid and stranded, provided the correct tool is used. Now I need to add to that. Do NOT trust the insulated crimps from unknown manufacturers, as supplied by many otherwise excellent electrical wholesalers until you have taken one from the pack, and snipped off the plastic to see that it is adequate (preferably after purchase g ). I found some today that had an excessive amount of the metal in the middle section removed, by my guesstimation, down to maybe 2.0 sq mm, or maybe less, and very soft squishy copper at that. Being that these crimps are rated for 12 AWG wire which is around 3.06 sq mm CSA, I consider this a dangerous defect. Fortunately I was warned by the fact that my Amp crimp tool just crimped them as if they were mere plastic, indeed, one broke in the middle, with the plastic holding the broken parts in place. A severe potential fire risk there, that would not have been caused by the usual suspects with crimps [poor crimping] but by what I consider to be a manufacturing defect. Suffice to say, strip connector got used instead, thank $DEITY I found it before energizing the 32 amp circuit they were on. Hope this forewarns someone and saves someone losing everything. If you're a bit bored/sad it's not too hard to cut through a crimpwith a junior hacksaw and sand the cut surface down with wet&dry to see how well it's crimped. If there is no air space between cable strand(s) and crimp it's a good sign. cheers, Pete. |
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