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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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#1
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If consumer unit moved, cables would be too short. solution?
If our consumer unit is moved by about a metre/3' 3" the upstairs
circuit cables would be too short to reach the CU. Would all the upstairs cables have to be replaced or could the cables be extended by jointing cables? |
#2
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If consumer unit moved, cables would be too short. solution?
fjk61011 wrote:
If our consumer unit is moved by about a metre/3' 3" the upstairs circuit cables would be too short to reach the CU. Would all the upstairs cables have to be replaced or could the cables be extended by jointing cables? They could be extended, for example by crimping, using a *proper* ratchet crimping tool like this http://media.digikey.com/photos/Paladin%20Tools%20Photos/MFG_1357.jpg Not a cheapo tool like this http://cache1.smarthome.com/images/89256.jpg |
#3
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If consumer unit moved, cables would be too short. solution?
On Nov 20, 8:05*pm, Andy Burns wrote:
fjk61011 wrote: If our consumer unit is moved by about a metre/3' 3" the upstairs circuit cables would be too short to reach the CU. Would all the upstairs cables have to be replaced or could the cables be extended by jointing cables? They could be extended, for example by crimping, using a *proper* ratchet crimping tool like this http://media.digikey.com/photos/Paladin%20Tools%20Photos/MFG_1357.jpg Not a cheapo tool like this http://cache1.smarthome.com/images/89256.jpg I think I have one of the ratchet crimpers or it might be a CAT5/6 tool. I'll check. |
#4
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If consumer unit moved, cables would be too short. solution?
On Nov 20, 8:05*pm, Andy Burns wrote:
They could be extended, for example by crimping, using a *proper* ratchet crimping tool like this http://media.digikey.com/photos/Paladin%20Tools%20Photos/MFG_1357.jpg Not a cheapo tool like this http://cache1.smarthome.com/images/89256.jpg If they're pre-insulated crimps and you're not Drivel-inept at using them, there's sod-all difference. |
#5
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If consumer unit moved, cables would be too short. solution?
In article
s.com, Andy Dingley writes If they're pre-insulated crimps and you're not Drivel-inept at using them, there's sod-all difference. I don't agree. I wouldn't trust a crimped 2.5mm^2 connection rated to carry 20A made with the cheapo tool. -- (\__/) (='.'=) (")_(") |
#6
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If consumer unit moved, cables would be too short. solution?
On Nov 21, 4:34*am, Mike Tomlinson wrote:
In article s.com, Andy Dingley writes If they're pre-insulated crimps and you're not Drivel-inept at using them, there's sod-all difference. I don't agree. *I wouldn't trust a crimped 2.5mm^2 connection rated to carry 20A made with the cheapo tool. -- (\__/) * (='.'=) (")_(") You're right. That's why it's best to solder. Especially if the cable will be bent about afterwards. |
#7
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If consumer unit moved, cables would be too short. solution?
On Nov 21, 4:34*am, Mike Tomlinson wrote:
If they're pre-insulated crimps and you're not Drivel-inept at using them, there's sod-all difference. I don't agree. *I wouldn't trust a crimped 2.5mm^2 connection rated to carry 20A made with the cheapo tool. I wouldn't be that keen myself. However I wouldn't trust a pre- insulated crimp made with either tool. The problem is that the insulator around a pre-insulated crimp is relatively soft and thick, which affects the ability of either tool to make an accurate crimp inside it. Crimps rely on an accurately shaped jaw to displace the connector in the right shape. Wrapping this up in something squishy makes for unreliable crimps, no matter which tool you apply to the outsides. |
#8
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If consumer unit moved, cables would be too short. solution?
On Nov 20, 7:44*pm, fjk61011 wrote:
If our consumer unit is moved by about a metre/3' 3" the upstairs circuit cables would be too short to reach the CU. Would all the upstairs cables have to be replaced or could the cables be extended by jointing cables? A very neat example of one method shown here. http://www.cucumber.demon.co..uk/cu1.jpg Allan |
#9
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If consumer unit moved, cables would be too short. solution?
On Nov 20, 8:05*pm, Allan Mac wrote:
On Nov 20, 7:44*pm, fjk61011 wrote: If our consumer unit is moved by about a metre/3' 3" the upstairs circuit cables would be too short to reach the CU. Would all the upstairs cables have to be replaced or could the cables be extended by jointing cables? A very neat example of one method shown here. *http://www.cucumber.demon.co.uk/cu1.jpg Allan Yeah, that's neat. Presumeably if we go down that route, the small box would be at the end of the existing cables and the new cables would come from the small box to the CU? |
#10
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If consumer unit moved, cables would be too short. solution?
replying to Allan Mac, TSIN Yeung wrote:
this makes no sense, why did this even need to extend those wires -- for full context, visit https://www.homeownershub.com/uk-diy...on-669682-.htm |
#11
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If consumer unit moved, cables would be too short. solution?
On 03/08/2019 19:14, TSIN Yeung wrote:
replying to Allan Mac, TSIN Yeung wrote: this makes no sense, why did this even need to extend those wires Saying nothing other than this was No1 when the OP made his post. https://www.youtube.com/watch?v=pa14VNsdSYM -- Adam |
#12
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If consumer unit moved, cables would be too short. solution?
On Nov 20, 7:44*pm, fjk61011 wrote:
If our consumer unit is moved by about a metre/3' 3" the upstairs circuit cables would be too short to reach the CU. Would all the upstairs cables have to be replaced or could the cables be extended by jointing cables? Or they can be extended by twisting togeter in a proper manner and soldering (with a blowlamp and using suitable flux.) They can be re- insulated with heatshrink sleeving. This is actually far better than crimps. Takes longer but you won't need the expensive crimping tool. |
#13
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If consumer unit moved, cables would be too short. solution?
On 21/11/2010 10:46, harry wrote:
On Nov 20, 7:44 pm, wrote: If our consumer unit is moved by about a metre/3' 3" the upstairs circuit cables would be too short to reach the CU. Would all the upstairs cables have to be replaced or could the cables be extended by jointing cables? Or they can be extended by twisting togeter in a proper manner and soldering (with a blowlamp and using suitable flux.) They can be re- insulated with heatshrink sleeving. This is actually far better than crimps. Takes longer but you won't need the expensive crimping tool. A blowlamp and flux? For the cable sizes used in a domestic CU? I don't think so! We're not trying to solder the bus-bars in a national grid switching station here. A proper soldering iron and regular cored solder is the order of the day. Additional flux is not required. You need to cut the wires to a sensible length, and I prefer to twist them together. This is to provide mechanical strength, and hold the joint still during soldering. I prefer to 'stagger' the join, so that the Phase, N and E are joined about a cm apart. It makes the job neater. I also use a double layer of heatshrink on each conductor, and then an overall single layer of heatshrink. -- Ron |
#14
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If consumer unit moved, cables would be too short. solution?
On Nov 21, 10:54*am, Ron Lowe wrote:
On 21/11/2010 10:46, harry wrote: On Nov 20, 7:44 pm, *wrote: If our consumer unit is moved by about a metre/3' 3" the upstairs circuit cables would be too short to reach the CU. Would all the upstairs cables have to be replaced or could the cables be extended by jointing cables? Or they can be extended by twisting togeter in a proper manner and soldering (with a blowlamp and using suitable flux.) *They can be re- insulated with heatshrink sleeving. *This is actually far better than crimps. *Takes longer but you won't need the expensive crimping tool. A blowlamp and flux? For the cable sizes used in a domestic CU? I don't think so! We're not trying to solder the bus-bars in a national grid switching station here. A proper soldering iron and regular cored solder is the order of the day. *Additional flux is not required. You need to cut the wires to a sensible length, and I prefer to twist them together. * This is to provide mechanical strength, and hold the joint still during soldering. I prefer to 'stagger' the join, so that the Phase, N and E are joined about a cm apart. * It makes the job neater. * I also use a double layer of heatshrink on each conductor, and then an overall single layer of heatshrink. -- Ron A soldering iron has not the heat to penetrate to the centre of a stranded cable. This method works fine. Cored solder will work but there's not really enough flux. With small cables it takes seconds to heat the cable up with a blowlamp. This was at one time the only way to joint cables. There is no possiblity of cables or screws loosening in any way. There is a system for twisting the cable strands in larger cable obviously unknown to you but it was all part of standard knowledge when I was an apprentice. Crimps are inferior in every way apart from saving time and money. |
#15
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If consumer unit moved, cables would be too short. solution?
Crimps are inferior in every way apart from saving time and money.
That's not the whole story though.Whilst it is faster and therefore cheaper to crimp , and I agree that apprenticeships used to teach making-off methods for cables (and indeed peope like BBC and MOD and BT had their own manuals for such tasks, and today companies still use such methods), I have read studies which show the crimping method to provide better reliability. Firstly, the joint between the cable conductors and the crimp is a cold-weld meaning a gas-tight joint with little or no chance of moisture ingress - solder is often full of pinholes (we're on about good joints which contain voids, not dry joints) which let in moisture and also may self-contain flux residues which can break down over time. Secondly, a solder-joint gives a mechanical point of weakness whereby vibration causes a fracture whereas with a crimp the crimp itself provides a degree of strain relief. Thirdly, repeatability is improved with crimping. DDS |
#16
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If consumer unit moved, cables would be too short. solution?
Duncan Di Saudelli wrote:
Crimps are inferior in every way apart from saving time and money. That's not the whole story though.Whilst it is faster and therefore cheaper to crimp , and I agree that apprenticeships used to teach making-off methods for cables (and indeed peope like BBC and MOD and BT had their own manuals for such tasks, and today companies still use such methods), I have read studies which show the crimping method to provide better reliability. Firstly, the joint between the cable conductors and the crimp is a cold-weld meaning a gas-tight joint with little or no chance of moisture ingress That's only true in the case of a very well made crimp using a tool capable of applying seriously high pressure. A cheap hand tool would not usually achieve this, and even the more expensive ratchet version would struggle. - solder is often full of pinholes Is it? I'd have thought this would be the case only when a joint has been inexpertly made. Presumably this is the result of not heating it well/long enough for the flux to boil out. which let in moisture This is easily excluded by coating with vaseline or silicone. and also may self-contain flux residues which can break down over time. But the honeycomb of solder should still be OK, unless you mean the residue or its breakdown products will attack and break down the solder itself. Secondly, a solder-joint gives a mechanical point of weakness whereby vibration causes a fracture whereas with a crimp the crimp itself provides a degree of strain relief. There are certain application areas where this is particularly problematic, e.g. within machinery or on vehicles where motor or engine vibration is to be expected. But you wouldn't expect vibration to be a problem in the vicinity of a domestic consumer unit. It is particularly discouraged to use solder in combination with crimp, because it compromises flexibility, or to solder-coat the ends of stranded wire intended to go into screw terminals, because in time the solder will suffer cold-flow, lowering the pressure of the screw on the wire, thus compromising the integrity of the joint. But a direct wire-to-wire join without screw terminals should be perfectly satisfactory if soldered. Thirdly, repeatability is improved with crimping. If you mean what I think you mean, namely that you are more likely than with the other methods to get consistent quality (all joints equally bad or good as the case may be) when making several joins in identical circumstances (the same type and size of wire, the same crimp terminals), then I reckon this would only be the case if using an expensive pukka crimping tool. With the ordinary hand tool I'd expect the joint quality to be highly variable. |
#17
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If consumer unit moved, cables would be too short. solution?
On 21/11/2010 11:06, harry wrote:
On Nov 21, 10:54 am, Ron wrote: On 21/11/2010 10:46, harry wrote: On Nov 20, 7:44 pm, wrote: If our consumer unit is moved by about a metre/3' 3" the upstairs circuit cables would be too short to reach the CU. Would all the upstairs cables have to be replaced or could the cables be extended by jointing cables? Or they can be extended by twisting togeter in a proper manner and soldering (with a blowlamp and using suitable flux.) They can be re- insulated with heatshrink sleeving. This is actually far better than crimps. Takes longer but you won't need the expensive crimping tool. A blowlamp and flux? For the cable sizes used in a domestic CU? I don't think so! We're not trying to solder the bus-bars in a national grid switching station here. A proper soldering iron and regular cored solder is the order of the day. Additional flux is not required. You need to cut the wires to a sensible length, and I prefer to twist them together. This is to provide mechanical strength, and hold the joint still during soldering. I prefer to 'stagger' the join, so that the Phase, N and E are joined about a cm apart. It makes the job neater. I also use a double layer of heatshrink on each conductor, and then an overall single layer of heatshrink. -- Ron A soldering iron has not the heat to penetrate to the centre of a stranded cable. This method works fine. Cored solder will work but there's not really enough flux. With small cables it takes seconds to heat the cable up with a blowlamp. This was at one time the only way to joint cables. There is no possiblity of cables or screws loosening in any way. There is a system for twisting the cable strands in larger cable obviously unknown to you but it was all part of standard knowledge when I was an apprentice. Crimps are inferior in every way apart from saving time and money. But we're not talking about 'larger cables'. A proper soldering iron ( eg 50W Temperature Controlled ) has plenty capacity to solder the cable sizes used in a domestic CU. -- Ron |
#18
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If consumer unit moved, cables would be too short. solution?
A soldering iron has not the heat to penetrate to the centre of a
stranded cable. This method works fine. Cored solder will work but there's not really enough flux. With small cables it takes seconds to heat the cable up with a blowlamp. This was at one time the only way to joint cables. There is no possiblity of cables or screws loosening in any way. There is a system for twisting the cable strands in larger cable obviously unknown to you but it was all part of standard knowledge when I was an apprentice. Crimps are inferior in every way apart from saving time and money. So how come in the RS book of words they say approved for use by the GEGB ?.. I've seen many crimps in Transmitter systems that use a lot more power than what your average detached house does;!.... -- Tony Sayer |
#19
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If consumer unit moved, cables would be too short. solution?
"harry" wrote in message ... Or they can be extended by twisting togeter in a proper manner and soldering (with a blowlamp and using suitable flux.) They can be re- insulated with heatshrink sleeving. This is actually far better than crimps. Takes longer but you won't need the expensive crimping tool. IIRC the figures show soldering to be less reliable than crimping. Screw terminals are the least reliable, hence the need for access to screwed joints but not to crimped or soldered. I would crimp them. |
#20
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If consumer unit moved, cables would be too short. solution?
Personally I would not crimp solid conductors.
To produce a correct cold weld involves several critical success factors; a crimp tool of the right type (single indent for fine stranded, circumferential impingement for stranded/solid); precise force applied consistently; correct crimp design for the conductor type (solid, stranded, fine stranded); crimp maker matched to tool maker (often forgotten). Personally I would never solder. Most people can learn to solder with even a little practice (avoid a dry joint), and learn to bind two solid conductors together with fine copper wire so the solder does not take the current & fault current, and learn to adhesive heatshrink (preferably in the appropriate colours). However for extending a CU it is a bit messy. I would always use DIN rail terminal block in a suitable enclosure. The CU uses such terminals, they are easy to access, inspect, maintain, alter, extend, reduce. Just bundle appropriate cables at entry to the enclosure with P-clips sized to hold the cables tight (so no load can be imposed on terminals), or route cables in trunking, etc. You can get DIN rail terminals & enclosure from Ebay, CPC, Farnell, RS, Rapid, electrical factors, lots of places online. The box may cost about £8, the DIN terminals and end-blocks will cost probably £15-20 depending on number. If in doubt, post the circuits and it only takes someone a few minutes to suggest the part numbers required. A novice might screw-up crimping or soldering, and right by a CU it is a cascading fire, whereas the probability of copying the photo with screw terminals is both safer and easier - it allows adjustment in future. Soldering & crimping does not (you end up running short of cable with changes, something a DIN terminal will prevent). |
#21
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If consumer unit moved, cables would be too short. solution?
On Nov 21, 9:48*pm, "js.b1" wrote:
You can get DIN rail terminals & enclosure from Ebay, CPC, Farnell, RS, Rapid, electrical factors, lots of places online. The box may cost about £8, the DIN terminals and end-blocks will cost probably £15-20 depending on number. If in doubt, post the circuits and it only takes someone a few minutes to suggest the part numbers required. A novice might screw-up crimping or soldering, and right by a CU it is a cascading fire, whereas the probability of copying the photo with screw terminals is both safer and easier - it allows adjustment in future. Soldering & crimping does not (you end up running short of cable with changes, something a DIN terminal will prevent). I'll probably go the DIN rail terminal route. I have a Hager enclosure for 8 modules (?) that I was going to use for a garage unit. The circuits a 6 mm^2 4 mm^2 Ring 2 x 2.5 mm^2 Lighting 2 x 1.5 (?) mm^2 |
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