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Inverter cable

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Created by julesmoto > 9 months ago, 10 May 2021
julesmoto
NSW, 1569 posts
10 May 2021 2:44PM
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So purchased this AWG 2 cable from RTM but had to remove one end as it was the wrong fitting. The end needs to be pushed into a circular inverter socket and secured by a grub screw but the wires are so fine that they will simply be cut off or separated by any grub screw. Perhaps I can purchase some sort of Circular swage to go on the end?? Also does anyone know if this type of core is any good or if it really even is tinned copper or whether perhaps I should get a more conventional cable with say 15 or so strands inside of greater thickness. I'm used to cables of this thickness being relatively stiff but if this 1.2 m cable is held by one end and wiggled it waves around like the core is silicone or something.

Ramona
NSW, 7732 posts
10 May 2021 6:26PM
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Fill the ends with solder. Finer the wire the better.

julesmoto
NSW, 1569 posts
10 May 2021 6:32PM
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Ramona said..
Fill the ends with solder. Finer the wire the better.


Thanks, just worried that the solder will just crack a part once the small grub screw bears down on it from the side

Charriot
QLD, 880 posts
10 May 2021 8:25PM
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Excellent wire, believe enclosed in silicon, extremely flexible good for vibration,
Good solder and terminating the end is a must.
swage, lugs, crimps terminals, pick what suited

Kinora
VIC, 187 posts
11 May 2021 8:57AM
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julesmoto said..

Ramona said..
Fill the ends with solder. Finer the wire the better.



Thanks, just worried that the solder will just crack a part once the small grub screw bears down on it from the side


+1 for Ramona's method. Solder is malleable and the soldered ends may squash under a grub screw but will only crack under very high pressures. As a bonus, once the ends are filled with solder, you can file them down to fit the terminal if required. Use a soldering tool that can supply lots of heat such as a big 240 VAC unit or even a fine, clean naked flame, not a small gas or 12 VDC unit. Fine multi-wire copper cables will conduct heat just as well as electrons, especially when the air gaps fill with solder. If the wire temperature falls too low as the solder starts to flow then you may be left with pockets of resin trapped in the solder which can lead to cracking. Use a good, fairly thick multi-cored solder because the cable will soak it up. Once installed, use some form of stress relief to stop the cable bending where the solder stops (e.g an inch or 2 from the end) or the wires will fatigue and break over time at this point.

Patience and neatness will be rewarded when working with high currents and low voltages.

Cheers,
Kinora

julesmoto
NSW, 1569 posts
11 May 2021 5:09PM
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Kinora said..

julesmoto said..


Ramona said..
Fill the ends with solder. Finer the wire the better.




Thanks, just worried that the solder will just crack a part once the small grub screw bears down on it from the side



+1 for Ramona's method. Solder is malleable and the soldered ends may squash under a grub screw but will only crack under very high pressures. As a bonus, once the ends are filled with solder, you can file them down to fit the terminal if required. Use a soldering tool that can supply lots of heat such as a big 240 VAC unit or even a fine, clean naked flame, not a small gas or 12 VDC unit. Fine multi-wire copper cables will conduct heat just as well as electrons, especially when the air gaps fill with solder. If the wire temperature falls too low as the solder starts to flow then you may be left with pockets of resin trapped in the solder which can lead to cracking. Use a good, fairly thick multi-cored solder because the cable will soak it up. Once installed, use some form of stress relief to stop the cable bending where the solder stops (e.g an inch or 2 from the end) or the wires will fatigue and break over time at this point.

Patience and neatness will be rewarded when working with high currents and low voltages.

Cheers,
Kinora


Thank you all for your excellent advice. Im in the process of buying a bigger soldering iron because mine simply won't heat that thickness of cable to the requisite temperature to allow solder to flow into it.

Ramona
NSW, 7732 posts
11 May 2021 6:06PM
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Try to use real lead solder as well.

Jode5
QLD, 853 posts
11 May 2021 8:43PM
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I am an Electrician and under no circumstances should a solder tip be placed under a screw or clamp. It is actually illegal to do under the Electrical wiring rules. Use a copper crimp pin or put the copper cable directly into the terminal. Using flexible cable can be awkward to get into the terminal but there are ways to do it and it can be done, you can even trim some strands of cable out as this will not effect the joint as there is very little resistance at that point. The reason why it is illegal and highly dangerous is because solder has no elasticity and when you put a screw or clamp on it, it will compress the solder and appear tight, but one slight bump or vibration which is guaranteed on a boat and the connection will become loose which in turn heats up and starts to melt the solder and things just get worse from there to finally a fire. This is common mistake the do it yourself electrical installers make. They seam to think it is a good idea, but it is the worst thing you can do especially with height current joints. DO NOT PUT A SOLDER JOINT UNDER A SCREW OR CLAMP.

Jode5
QLD, 853 posts
11 May 2021 8:56PM
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Select to expand quote
Ramona said..
Fill the ends with solder. Finer the wire the better.


Ramona, usually your advice is very good, but this time you are totally incorrect, is is actually illegal to put a solder joint or tip under a screw or clamp. Probably a good way to void your insurance. It doesn't pay to give electrical advice if you are not qualified. I see so much bad electrical advice on forums and Facebook.

Jode5
QLD, 853 posts
11 May 2021 9:06PM
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Kinora said..

julesmoto said..


Ramona said..
Fill the ends with solder. Finer the wire the better.




Thanks, just worried that the solder will just crack a part once the small grub screw bears down on it from the side



+1 for Ramona's method. Solder is malleable and the soldered ends may squash under a grub screw but will only crack under very high pressures. As a bonus, once the ends are filled with solder, you can file them down to fit the terminal if required. Use a soldering tool that can supply lots of heat such as a big 240 VAC unit or even a fine, clean naked flame, not a small gas or 12 VDC unit. Fine multi-wire copper cables will conduct heat just as well as electrons, especially when the air gaps fill with solder. If the wire temperature falls too low as the solder starts to flow then you may be left with pockets of resin trapped in the solder which can lead to cracking. Use a good, fairly thick multi-cored solder because the cable will soak it up. Once installed, use some form of stress relief to stop the cable bending where the solder stops (e.g an inch or 2 from the end) or the wires will fatigue and break over time at this point.

Patience and neatness will be rewarded when working with high currents and low voltages.

Cheers,
Kinora


That's a load of rubbish. You are obviously not in the electrical game.

julesmoto
NSW, 1569 posts
11 May 2021 9:23PM
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Select to expand quote
Jode5 said..

Ramona said..
Fill the ends with solder. Finer the wire the better.



Ramona, usually your advice is very good, but this time you are totally incorrect, is is actually illegal to put a solder joint or tip under a screw or clamp. Probably a good way to void your insurance. It doesn't pay to give electrical advice if you are not qualified. I see so much bad electrical advice on forums and Facebook.


So why is it illegal? What is wrong with it?

Jode5
QLD, 853 posts
11 May 2021 10:51PM
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Select to expand quote
julesmoto said..

Jode5 said..


Ramona said..
Fill the ends with solder. Finer the wire the better.




Ramona, usually your advice is very good, but this time you are totally incorrect, is is actually illegal to put a solder joint or tip under a screw or clamp. Probably a good way to void your insurance. It doesn't pay to give electrical advice if you are not qualified. I see so much bad electrical advice on forums and Facebook.



So why is it illegal? What is wrong with it?


I thought I explained it in my other post what's wrong with it. It is illegal because the Australian Standards say so. I am extremely experienced in this area and have had to repair many soldered burnt terminals over the years. It was one of the first thing I was told when I started my apprenticeship 50 years ago.

julesmoto
NSW, 1569 posts
12 May 2021 1:36AM
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Select to expand quote
Jode5 said..

julesmoto said..


Jode5 said..



Ramona said..
Fill the ends with solder. Finer the wire the better.





Ramona, usually your advice is very good, but this time you are totally incorrect, is is actually illegal to put a solder joint or tip under a screw or clamp. Probably a good way to void your insurance. It doesn't pay to give electrical advice if you are not qualified. I see so much bad electrical advice on forums and Facebook.




So why is it illegal? What is wrong with it?



I thought I explained it in my other post what's wrong with it. It is illegal because the Australian Standards say so. I am extremely experienced in this area and have had to repair many soldered burnt terminals over the years. It was one of the first thing I was told when I started my apprenticeship 50 years ago.


Sorry you posted twice in a row and I must have only read your second one

Crusoe
QLD, 1197 posts
12 May 2021 6:10AM
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You could put a boot lace Ferrell on it. Just google it, you'll see.

Datawiz
VIC, 605 posts
12 May 2021 7:29AM
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Select to expand quote
Jode5 said..
I am an Electrician and under no circumstances should a solder tip be placed under a screw or clamp. It is actually illegal to do under the Electrical wiring rules. Use a copper crimp pin or put the copper cable directly into the terminal. Using flexible cable can be awkward to get into the terminal but there are ways to do it and it can be done, you can even trim some strands of cable out as this will not effect the joint as there is very little resistance at that point. The reason why it is illegal and highly dangerous is because solder has no elasticity and when you put a screw or clamp on it, it will compress the solder and appear tight, but one slight bump or vibration which is guaranteed on a boat and the connection will become loose which in turn heats up and starts to melt the solder and things just get worse from there to finally a fire. This is common mistake the do it yourself electrical installers make. They seam to think it is a good idea, but it is the worst thing you can do especially with height current joints. DO NOT PUT A SOLDER JOINT UNDER A SCREW OR CLAMP.


Yep, what he said....

Bananabender
QLD, 1610 posts
12 May 2021 8:16AM
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Thats good to know jode5 . I recently purchased and installed a NASA wireless
wind speed/ direction system which I purchased direct from the UK.
The cables (3) to connect the base unit to the display had , what looked to me , solder dipped ends to insert into screw clamps in the base unit. I shortened the cable cutting off the ends but at the time thought what a great idea .
edit:
or is it solder?




Ramona
NSW, 7732 posts
12 May 2021 8:55AM
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It's solder.

Kinora
VIC, 187 posts
12 May 2021 9:07AM
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Apologies, julesmoto. My advice was given in good faith and based on personal experience over many years. You should, of course, follow the advice of qualified professionals.

K.

DrogueOne
215 posts
12 May 2021 9:09AM
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Interesting discussion, In the electronics world I was taught to solder components and leads where appropriate and use untinned wire in screw clamps. Screw has to clamp down on the wire strands and the edge of the insulation. Obviously different use, much smaller power carrying and always with additional strain relief.

You see a lot of reference to tinned wire, have to admit I'm a little confused about what is what. It seems tinned strand is good (i.e. the strands in the wire are tinned during wire construction) but tinning the ends of the wire is bad?

This is a good read on termination, the bit about solder or not is a long way down.
marinehowto.com/marine-wire-termination/

Achernar
QLD, 395 posts
12 May 2021 1:29PM
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DrogueOne said..
This is a good read on termination, the bit about solder or not is a long way down.
marinehowto.com/marine-wire-termination/


Most interesting read, mainly because I did not know how much I did not know. My previous attempts at DIY wiring have been pretty horrible to date, but the article provides a good start on where I might have been going wrong. When I read the first post in this thread, I thought you should tin it with solder. Not now. I have been contemplating some re-wiring as part of the many, many jobs to do on my boat, but the article gives a much clearer picture of what is involved (including some decent tools and crimps).

Gos2017
NSW, 47 posts
12 May 2021 2:24PM
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Slight tangent but related:
So is it better to solder a lug on a battery cable or crimp with an appropriate tool?? (Similar cable size as OP, 2 B&S)

Jode5
QLD, 853 posts
12 May 2021 2:25PM
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Select to expand quote
Bananabender said..
Thats good to know jode5 . I recently purchased and installed a NASA wireless
wind speed/ direction system which I purchased direct from the UK.
The cables (3) to connect the base unit to the display had , what looked to me , solder dipped ends to insert into screw clamps in the base unit. I shortened the cable cutting off the ends but at the time thought what a great idea .
edit:
or is it solder?





Soldering the ends on electronic device sensors is not so critical as they draw little or no current which creates heat. Heat is what causes the connection to fail very quickly. In someways I think it is better to tin tip (solder) electronic device sensor cables as it reduces the buildup of vertigrass ( green stuff) if the cable is not pre tinned cable. If the cable is tinned cable you don't need to solder. When soldering any cables make sure you use electrical grade solder which has a higher tin content (Bunnings have it). Crimped on pins are by far the best option making sure they are crimped with the correct tool and not pliers or any other DIY means. Tinned cable is best for boats especially where the conductors are fine flexible cables as if salt water gets on the cable it will eat away at the copper. Ideally you don't want salt water on any electrics whatsoever.

When joining cables, soldering is by far the best way ( just don't put it under a screw after you solder it) then use glue lined heat shrink, self amalgamating tape or even liquid tape with normal insulation tape over the top to seal the joint. Avoid using plugs to join unless they are proper water proof plugs. I am not a great lover of crimp joiners unless they are in a completely dry area and the correct crimp tool is used. just remember the higher the current draw, the higher the chance of failure if the cable tip is soldered and under a screw. In the case of the above inverter where it is capable of drawing over 100amp the danger is extreme. If anyone has any specific electrical questions I am always only to happy to answer them.

Jode5
QLD, 853 posts
12 May 2021 2:28PM
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Select to expand quote
Gos2017 said..
Slight tangent but related:
So is it better to solder a lug on a battery cable or crimp with an appropriate tool?? (Similar cable size as OP, 2 B&S)


Either way is fine. When crimping make sure you use the correct size lug and correct crimpers.

Bananabender
QLD, 1610 posts
12 May 2021 5:05PM
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Jode , I have been using solder splice heatshrink ,applying heat and then covering with preglued heat shrink when joining cables after winding the wires together with the join covered by the solder before applying heat. Acceptable?

Jode5
QLD, 853 posts
12 May 2021 6:52PM
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Select to expand quote
Bananabender said..
Jode , I have been using solder splice heatshrink ,applying heat and then covering with preglued heat shrink when joining cables after winding the wires together with the join covered by the solder before applying heat. Acceptable?


I have seen them used but am a bit skeptical as it must be very low melt solder and would think the copper cable would want to be in very good condition for it to take. I would not like to use them on anything that is using to much power. I have not seen one fail, but also have not had much to do with them.



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"Inverter cable" started by julesmoto