Crimping for Caravaners (for amusement)

[DetlefSchmitz]

Or put in a swearword and then report yourself to a moderator.

 

[flameport]

Perfectly acceptable method for a caravan.
The more faulty and defective connections inside, the faster the thing will be totally destroyed. Particularly if they use a similar connection technique for the gas.

 

[ban-all-sheds]

I can't work out how to delete this post.

Dont think you can, you can use the EDIT and delete each letter down to leave just 3 characters

IIRC it used to be that if you replaced a post with just it would trigger a deletion.

 

[ericmark]

With automotive lugs they are designed to be soldered and have a thinner shell and no hole at the end of the cable tube. But for crimping there is often a small hole and you can't fill it with solder and then insert the fluxed cable into the cup half filled with molten solder. In the reverse using automotive lugs with a crimping tool does not work either as the walls are too thin.

As to cable size with the boat which is similar to a caravan electrics wise getting 75mm² cables from battery to inverter was no easy task, so we used 2 x 35mm² cables. 3kVA with no losses is 250A with loses then easy to exceed a 300A drain on the battery. In our case the battery was a little on the small size only 480 Ah so could not maintain that draw for long.

OK maybe not 3kW with a caravan but a 1kW inverter is common and the motor mover also takes a fair draw from the battery. A starter motor can hit 300A draw however for a very short time, so automotive cable amps rating seems to have no connection to the same cable used with low voltage. We would never dream of drawing 200A on 16mm² but it is common with automotive. It really is a different world.

 

[SimonH2]

Wet rag around the end of the cable, fierce flame on the oxy-acetylene to heat the lug quickly ...

I've done that in the past. Many years ago I went to the local "professional" automotive electrics place in town to get some customer battery cables made - that was when I was looning around in an Escort (not the new fangled one with the drive on the wrong wheels, but the proper ones with the drive on the correct rear wheels) and needed to fit a master switch. it would be hard to think of any more ways of "fail" they could have managed.
To start with, ever end had burned insulation hidden underneath insulation tape.
And if someone asked for "10mm ring terminals" (though could have been 8mm) would you fit a) terminals with an 10mm hole, or b) terminals with a 6mm hole ? They chose b ... because ... a 10mm spanner fits the nuts for a 6mm terminal so clearly that's the size I wanted
Given that they claimed it was "not possible" to solder the terminals without burning the insulation, and they didn't have time to redo them while I waited, they gave me the right terminals and I did it properly at home. One of those "if you want it doing properly ..." lessons in life.

I've come across this "size of spanner" business a few times, I suppose it must make sense to some people.

 

[conny]

Sent an 'ex-military' sparky for an 8mm nut last week. Unknown to me he took an 8mm spanner with him and came back with a 5mm nut.
Explained I needed an 8mm nut, "the size you use a 13mm spanner on." He came back about 20 mins later saying there were none in the rack. (Unbelievable as we carry a minimum of 200 in stock at all times). So we both go back to the workshop and I immediately pick up an 8mm nut. Turns out, after I explained it to him, that he had only half heard what I had said and had been looking for a 13mm nut!

 

[ericmark]

So you found the nut, even before you found the steel nut?

The big problem I had was auto cable came in the old imperial sizes and the mains lugs would not fit. Seem to remember sizes like 65mm and 12mm I will guess there would be an imperial exact size.

With my screw in the end to set size crimp pliers 10 ~ 120 mm I was OK. But the more expensive types with dies of each size you just could not get the dies to match. I do remember being sent to the car park to renew the lug on a wagons starter motor. Lucky my car was in same car park with my crimps in the boot so switched of isolator crimped on new lug connected to starter and job done. Could not have possibly soldered in place it would have been remove cable and refit cable.

So 10 minutes latter I am sitting having my cup of tea at normal break time job done. Boss starts with we don't have a cup of tea when there is a wagon waiting get the job done first. If seems he had never seen a set of 10 ~ 120 mm crimp pliers and looked at the set in my boot in amazement. Any wonder why no longer trading?