Terminating large cables

lustyd

lustyd

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what’s the best way to terminate big power cables for use on the boat? I’ve never done this before but it’s certainly something I feel I should be able to handle myself. I’m assuming a crimp tool is needed but any goop to prevent corrosion or heat shrink etc?
 
What do you call big?
I have a ck crimper that does upto 50mm? square cable (starter cable size) with correct lugs. I think that it starts at 8mm square. Purchased it for fitting the electric windlass years ago and still use it.

Edit. Just got them from the garage. 6 to 25mmm cable. CK T3676 and for non insulated terminals.
 
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The hydraulic crimping tools are good solution. Use good quality lugs and glue lined heat shrink and tinned cable.
The 12T versions are slightly better and will crimp the larger cables. They are only slightly more expensive than the smaller 9T models.

Cembre lugs are good quality.
 
I prefer to have a method I can modify without the use of specialist tools.

This style have advantages if you have the room to accommodate them:


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The type that uses pinch screws are unreliable but these are very positive and have the bonus that you can simply add lighter wires to the pinch bolts as you need them. If you are starting from scratch the more flexible cables are well worth having, they make things much easier.

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PaulRainbow said:
Hydraulic crimper is the way to go: Hydraulic Crimper 8T Crimping Tool Tube Terminal Lug Battery Cable Wire durable | eBay Use proper lugs: Copper Tube Terminals - 35mm² Cable I also add some heat shrink.
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The main point from my point of view is then this crimper has hex dies that will give a better crimp then the indent on just one side like the one I was given.

If an indent on one side is OK for you you could simply use a nut in a vice but this again does not give a proper crimp as it only just squashes the crimp rather than "shrinking" the tag around the cable.
 
Rogershaw said:
The main point from my point of view is then this crimper has hex dies that will give a better crimp then the indent on just one side like the one I was given.

If an indent on one side is OK for you you could simply use a nut in a vice but this again does not give a proper crimp as it only just squashes the crimp rather than "shrinking" the tag around the cable.
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That's spot on Roger. The hydraulic tool with the dies will squash the cable so tightly there isn't even an air gap between the cable strands.
 
Thanks all, I probably should have said a good job is worth more than the money to me so the better tools are my preference every time (up to a point!!). I already have a bunch of big heat shrink so I'll grab a hydraulic crimper and should be good to go, thanks again.
 
Finally, I assume given Paul's link for terminals that 35mm would be the "normal" cable for battery connections on a yacht? just looking to buy a few for practice at the mo and it's certainly not an essential trip to go to the boat and check :D
 
lustyd said:
Finally, I assume given Paul's link for terminals that 35mm would be the "normal" cable for battery connections on a yacht? just looking to buy a few for practice at the mo and it's certainly not an essential trip to go to the boat and check :D
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There is no "normal" size, it will depend (to a degree) on the engine/boat size, unless it's a recent Bavaria, which will have massively over rated cables. But, although i only linked to the 35mm cables as an indication of style, 35mm is common on small to mid range yachts.

A Sun Odyssey 36.2 may well have 35mm cables, but i can't guarantee that.
 
duncan99210 said:
I use one of these Heavy Duty Battery Terminal Crimping Tool Car Van Wire Cable Lug Connector Crimp | eBay for cable crimping. I then use either heat shrink tube or self amalgamating tape to finish the job off.
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+1. Used with a 7lb club hammer makes a beautiful tight, 3 sided crimp plus it’s small enough to keep in the toolbox onboard for repairs/alterations whilst cruising. Only downside is it can’t usually be used on cables in situ - I don’t think using the engine as an anvil is generally recommended...
 
Thanks again all. 50mm doesn't look crazy there so I feel I may as well use that given the very short cable runs needed. This is for the shunt wiring so may as well go bigger rather than smaller.
 
Decent cable cutters are a must have if you are using very flexible cables with multiple thin conductors. Side cutters are ok for thinner cables with not so many conductors but for larger extra flexible cables it is difficult to get a clean cut and an easy entry into the crimp terminal without using something like this to cut the cable:
Heavy Duty Cable Cutters - Max. Cable 70mm²
 
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