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Electrical crimps gotta be done right!


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After reinstalling the engine last week I hooked all the wire-y and tube-y bits up and hit the go-switch.  Nothing.  Blank looks. 

Voltmeter across the engine earth and live finds nothing. 0.00v or near as dammit.

6.00pm and fading light and it had been a big day, so I locked it all up and left.

Came back yesterday full of the joys and with capacity to think.  Looked at the live cable to the starter and thought "thats an odd angle its sitting at."

Reached down, grabbed the cable and it fell off the "crimped" terminal...

Off to the local autosparky who happily and properly crimped two new terminals onto the cable.  Problem solved.

Folks, when you crimp electrical connections it is NOT just crushing the terminal onto the wire.  You cannot do it effectively in a vice, which appears to be what some previous owner had done, and then covered the evidence with heatshrink!  If you haven't got the right tool, NOTHING else will suffice and it may leave you unable to start in embarrassing (or worse) locations than I had (think, lee shore, running out of sea room, gathering dark, etc).

Same goes for low current circuits.  Good crimp connections are great - electrically and mechanically sound.  But to do them you need the right tools.  If you are using crimp connectors, get the right crimping pliers (not those pressed-tin POS things)and you will be happy and safe.

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1 hour ago, aardvarkash10 said:

After reinstalling the engine last week I hooked all the wire-y and tube-y bits up and hit the go-switch.  Nothing.  Blank looks. 

Voltmeter across the engine earth and live finds nothing. 0.00v or near as dammit.

6.00pm and fading light and it had been a big day, so I locked it all up and left.

Came back yesterday full of the joys and with capacity to think.  Looked at the live cable to the starter and thought "thats an odd angle its sitting at."

Reached down, grabbed the cable and it fell off the "crimped" terminal...

Off to the local autosparky who happily and properly crimped two new terminals onto the cable.  Problem solved.

Folks, when you crimp electrical connections it is NOT just crushing the terminal onto the wire.  You cannot do it effectively in a vice, which appears to be what some previous owner had done, and then covered the evidence with heatshrink!  If you haven't got the right tool, NOTHING else will suffice and it may leave you unable to start in embarrassing (or worse) locations than I had (think, lee shore, running out of sea room, gathering dark, etc).

Same goes for low current circuits.  Good crimp connections are great - electrically and mechanically sound.  But to do them you need the right tools.  If you are using crimp connectors, get the right crimping pliers (not those pressed-tin POS things)and you will be happy and safe.

Yep, one of the prime causes of electrical fires.

I have 3 or 4 cable crimpers, if anyone needs to borrow one, or wants a cable done. Quality crimpers often stamp the cable lug with the size the crimp tool was set to, so you can check the cable size is correct. Properly done they are watertight. Bad/low quality crimpers often leave "dog ears" on the sides... 

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Also when stripping the cover off good sized wires CHECK you don't have wire that has a lightweight gladwrap like skin over the wire itself under the far bigger far gruntier plastic coating. We've had 3 instanced in the last year where new anchor winch installs suffered WTF power supply issues. All 3 had the wires crimped professionally, all 3 times the professionals missed this skin, it is very hard to spot and is only on some wires. But it is enough to cause issues and once under the crimp its invisible which makes diagnosing it just a guess.

The first time we just couldn't figure it out, new wires and all that so should be fine. In desperation I said check each wire just to make sure one hasn't broken when dragging it from the batteries to the winch, expect to find all were spot on. But one short wire got a flickering reading so I fiddled with the crimps and it got worse so pulled one end off to re-crimp it thinking a poor squeeze to find the glad wrap under it. The other 2 installs were WTF until I remembered and thought, lets check each wire to find........ hello, gladwrap again.

It maybe just one brand of wire, I never did find out, but whatever it is it is being sold in NZ.

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Its the maritime approved cable - 5000.1 spec - actually has 3 layers - outer sheath, inner sheath, and the thin celophane like membrane, then multistrand  tinned copper cable. It surprises me that the correctly sized lugs would fit over the celophane - proper lugs only just fit over the bare cable.....

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4 minutes ago, ballystick said:

I like these ferrule terminal end type of crimps, I haven't seen them in NZ though

 

They sell those at most electrical wholesalers , Ideal Electrical / JA Russels etc.. 

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Yes they are really common. You can use them without a crimper. Just twist the bare end and slip it into the jacket, place the terminal into the terminal and tighten up. These things stop the clamping screw from cutting through the wire end and add a little extra stress relief to the connection.
However, if you want to crimp the jacket onto a wire, you need the proper tool and they are very expensive. It is best to not try crimping with anything else as it just does not work well.
I also place a little heatsrink on the wire end and slip over that plastic jacket of the terminal just to give it a little extra hold. The plastic skirts on these things are not make to be cruched down like the standard Ring type terminals.

IT mentioned about crimping tools and that there are some nasty ones out there. Refering to the larger battery terminal type crimps of course. The real McCoy's have a Hex action that crimps the terminal equaly from all sides and leaves a nice hex pattern around the terminal. The cheap ones have two sets of die that have three sides each and they are simply crunched together and end up leaving two tags each side and a very poor crimp that can fail. OInce again, the real tools are expensive. Don't buy the cheap rubbish from the likes of Jaycar etc. Expect to pay several hundred for good cheapies and into the thousands for the hydraulic action ones.

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16 hours ago, Island Time said:

Its the maritime approved cable - 5000.1 spec - actually has 3 layers - outer sheath, inner sheath, and the thin celophane like membrane, then multistrand  tinned copper cable. It surprises me that the correctly sized lugs would fit over the celophane - proper lugs only just fit over the bare cable.....

Oh is that a specification, I didn't know that. It certainly was a trick one. It caught at least 3 professionals out.

The crimps are probably like a vast array of goodies that are made imperial but sold as metric and the other way around, maybe the wire was off spec or the wire and crimps were at either end of the allowable tolerance range. The wire was reported to be LR Approved.

We run into it a lot...I even did mid Sth Pacific ocean when replacing a broken water impeller. The spare pumped but not in volume so I couldn’t get much more than a fast idle before overheating. On return we found it as a converted one so a fraction of a mm different than expected stopping it seal on the end plate properly to give us full flow.

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Yes Wheels, the crimping tools for the ferrules selling for around $350. I like the way they seal off the wire ends and support the terminal wiring at the stress point area

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One set was done by a sparky who now runs a chandlery, the other 2 were done by a dude whose card claims he is a marine electrician.

I made a set for the farms small solar array over Xmas, as would be expected they are perfect. It's not like it's rocket science or takes more then 30 seconds to check all is good is it.

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3 minutes ago, KM... said:

I made a set for the farms small solar array over Xmas, as would be expected they are perfect. It's not like it's rocket science or takes more then 30 seconds to check all is good is it.

True.

Its nearly as simple as terminating wire rope.  ;-)

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3 hours ago, ballystick said:

Yes Wheels, the crimping tools for the ferrules selling for around $350. I like the way they seal off the wire ends and support the terminal wiring at the stress point area

The bootlace one? 

https://www.ideal.co.nz/nzi/Category/Tools-Instruments/Hand-Press-Cut/HNKE10-Bootlace-Crimp-Tool-Dieless-75-10mm/p/CABHNKE10

thats about $112. They had some one sale for around $80 the other day. $350 is way, way too much

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14 minutes ago, aardvarkash10 said:

True.

Its nearly as simple as terminating wire rope.  ;-)

Way easier than rigging wire. Bending 1x19 into thimbles etc is a huge pain in the butt. 

I used one of those crimp punch thingys, no idea what they are called. You put the wire/crimp in and whack down a punch like thing that puts divot, so to speak, into it. A few on each crimp and it ain't coming off ever again...I know I cocked up a colour so tried. Wire cutters won that one :)

I'm a strong user of the right colours in the right places as who knows who'll be looking in there next. I have opened things up to find 100 odd wires, every single one of them the same colour, sort of thing and more than once.

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24 minutes ago, KM... said:

I'm a strong user of the right colours in the right places as who knows who'll be looking in there next. I have opened things up to find 100 odd wires, every single one of them the same colour, sort of thing and more than once.

I did some work for a friend who is an aircraft mechanic once.  Cessna 150.

Every wire was white.  I couldn't believe it.  A tiny serial number printed every 300mm or so along the wire identified the circuit, but it was unreadable unless you were equipped with Mr Magoo glasses.

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27 minutes ago, KM... said:

A few on each crimp and it ain't coming off ever again...I know I cocked up a colour so tried.

Actually, the approved method is single press (just like olives and coffee!).  Multiple presses on the same terminal fatigues the wire and leads to early breakages.  It won't come off if you try immediately, but it work hardens (especially copper) and fails later.

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8 hours ago, Winter said:

thats about $112. They had some one sale for around $80 the other day. $350 is way, way too much

Expensive depends. Even with tools that "do the job OK" there is cheap and there is quality. It depends on the user. A pro doing lots of connections daily would be looking at the expensive end of the market. The likes of you and me need cheap as posible that can still get the job done OK. And of which, looking on trademe returned a great range of crimping tools, ranging from cheap through to mega expensive.
The annoying thing to me is that there are so many different types of crimp pins in the World, each requiring a specific type of crimping tool, that if you are in the game, you need to carry a truck load of very expensive tools.

Now, re this 5000 series cable. I have run and terminated litterally miles of this stuff through Stadiums around NZ. The main reason for us using it was the fire rating requirements. To strip the jacket and leave behind the clear plastic wrap means two things. Firstly, the user did not use the proper wire termination stripper tool. For a few connections, it is not critical, but if doing lots, the best tool is one that has a cutter of the correct wire diameter that cuts the entire multeple insultating jackets right through and the pulls the waste away from the cable in one complete action. It is essential that none of the conductors are damaged in anyway. The tolerances to do all this precisely are extreme close. The best tool on the market was made by a German manufacturer called Klien. However there are many cheaper makes that also work just as well.
Secondly, for anyone only doing a few ends without the right tool, it is totally possible, but just a little harder to do and thus inspection of the end should be carried out after stripping and the failure to remove the clear plastic should have been obvious. Any proffesional sparky should have known better and was not practicing in a proffesional way. Not saying that I am surperior to them. We have all made dumb mistakes over time. It's just that such mistakes should be used as a lesson to be better.

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7 hours ago, marinheiro said:

Great tools, actually always made in USA

Well whaddaya know. I had always thought that by the name and quality they were naturally German.

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