Cable Lugs or 1/0 cable

[brulaz]

Originally setup to just run a small coffee grinder, we're now trying to pull 70ADC from the batteries to run an induction hotplate.

For some reason, these things always seem to get out of hand ... :R

Anyway it's time to upgrade the cables to and from the 1000W inverter. (And maybe later a 2000W inverter will happen.)
Was thinking about 1/0 cable, about 8-12' depending upon routing.

The old cables used simple tinned copper lugs with a V-crimp made with a "Heavy-Duty Hammer Crimper" from Del-City. And lots of electrical anti-corrosion paste, also from Del-City.

Would similar V-crimped lugs be adequate for the new 1/0 cables? Or do they add too much resistance at high loads? The old cables do seem to have more voltage drop than I predicted based solely on the cable length and size.

Alternative lugs might be the Fusion solder lugs. Not cheap, but I only need 4 and still cheaper than a $200-300 crimping tool.

And then I hear of people using thick walled copper pipe? And solder?

I would rather cut and lug the cables myself as I'm not exactly sure of their routing.

Thanks.

[wa8yxm]

If you are planing on possibly a 2KW inverter go with 4/0 cable at minimum for a short run, Even larger for a longer run.. My run is only a couple of feet and I think I'm running 6/0 AND DO NOT FORGET THE FUSE.

[hedge]

I bought one of those ebay crimpers, pretty decent for the cost. My case came cracked but no big deal. I've only done about 10 crimps with 2 gauge and it worked great.

[brulaz]

Thanks all.

Those YQK hydraulic crimpers have gotten really cheap, $-wise. Got the smaller YQK-70 that only goes upto 70 (mm or 2/0 ?) for US$28.52 (plus the Canada shipping etc). Not expecting any great quality for that price, but should work for a few crimps anyway.

Batteries on the tongue, inverter in the pass-thru, pretty sure I can get the total cable run down to 9' if I run them directly through the trailer nose, not down under and up as they are now. So hopefully 1/0 will be adequate.

[MEXICOWANDERER]

I cannot emphasize the importance of maintaining the tin coating in perfect shape. I've had to replace 100 and 200 amp service entry boxes that were ruined beyond repair because some genius licensed contractor neglected to inspect a fitting. Ever see melted aluminum? I am attempting to encourage folks to annotate suggestions about aluminum fittings to append tin plated in good condition. When in doubt, replace. Tin plating is fragile - it is not chromium. How many dozens of bolted cable terminations have I replaced...

The 2 piece battery lugs that use ring threaded compression work on an entirely different principle. Still doubtful? Now go unplug and take the cover off your breaker box and start tightening set screws set in ALUMINUM. The enemy here is vibration. When houses get up and scamper over rough roads the same thing will happen. Forget Pazo or whatever the name of cosmoline product is - use something like T&B COPPER compound. It's stouter and lasts longer. Cosmoline was the "Hot Setup" in WW1 when they were shipping 30-06 to the trench troops.

[Gdetrailer]

brulaz wrote:
Originally setup to just run a small coffee grinder, we're now trying to pull 70ADC from the batteries to run an induction hotplate.

For some reason, these things always seem to get out of hand ... :R

Anyway it's time to upgrade the cables to and from the 1000W inverter. (And maybe later a 2000W inverter will happen.)
Was thinking about 1/0 cable, about 8-12' depending upon routing.

The old cables used simple tinned copper lugs with a V-crimp made with a "Heavy-Duty Hammer Crimper" from Del-City. And lots of electrical anti-corrosion paste, also from Del-City.

Would similar V-crimped lugs be adequate for the new 1/0 cables? Or do they add too much resistance at high loads? The old cables do seem to have more voltage drop than I predicted based solely on the cable length and size.

Alternative lugs might be the Fusion solder lugs. Not cheap, but I only need 4 and still cheaper than a $200-300 crimping tool.

And then I hear of people using thick walled copper pipe? And solder?

I would rather cut and lug the cables myself as I'm not exactly sure of their routing.

Thanks.

I used refrigeration copper tubing with a homemade punch setup which consisted of a piece of steel pipe clamped in a vise, I cut a slot in the steel pipe and the vise kept the pipe from spreading.

Put the copper pipe inside the steel pipe, a couple of good wacks with hammer and punch held the copper pipe firmly to the wire.

Then I used a propane torch to heat the copper pipe and lots of electrical solder (I made sure the copper pipe was scrubbed clean on the inside using sand paper)..

I used two sizes of copper tubing small size to fit the wire then the next larger size fit over the small tubing and solder completed the whole thing.

The result is a copper lug that can easily handle well over 200A of current and never even get above room temp.

I first did this with some welding cable to extend my stick welder leads.. Worked perfect and was able to max the welder at 250A..

Much more meat in my setup than any of the welding lugs I looked at.

Yep, the crimp vs solder folks should be chiming in shortly to blast me for my home made lugs :R

[azrving]

2oldman wrote:

MEXICOWANDERER wrote:
Cu Al direct connection is dangerous. A fire waiting to happen.

Set screw terminations WILL loosen if vibration strikes a nasty chord with heating and cooling.

Same admonitions I got last time. The connector shown is rated al/cu. Worked perfectly for 10 years.

Just another suggestion for OP. He is free to choose whatever allows him to sleep at night.

Heck of a lot better than a hammer scrimper

[time2roll]

12' is a long run to a large inverter. I would get 4/0 if you are going 2000w.

Four crimps is $4 all premade and shipped right here:
http://www.genuinedealz.com/custom-cables?size=49

12' 1/0 AWG, 2 lugs, heat shrink, procrimp and ship $70.

[azrving]

As Mex said except throw the hammer crimp in the lake. I have the ebay hydraulic crimper and it works fine. The dies might not be numbered correctly as stated on some threads but it doesn't matter as it's easy to figure out. Get a few extra terminals and do some test crimps. If the edges of the die start to bite the side of the terminal stop and move the die so a flat area is now on the bite marks. I have a couple that do that and may need to file the edges just a little. I've also used it to install a friends solar system and repair some old crimps. For $36.00 you cant beat it. The friend that I helped bought one and said he just wanted to have one because it was so good and so cheap.

Heavy draw cables such as that are crimped not soldered. Solder is excellent for small terminals that are hand plier crimped and used outside on things like trailer lights etc.

[2oldman]

MEXICOWANDERER wrote:
Cu Al direct connection is dangerous. A fire waiting to happen.

Set screw terminations WILL loosen if vibration strikes a nasty chord with heating and cooling.

Same admonitions I got last time. The connector shown is rated al/cu. Worked perfectly for 10 years.

Just another suggestion for OP. He is free to choose whatever allows him to sleep at night.

[MEXICOWANDERER]

Hay ZEUS!

Cu Al direct connection is dangerous. A fire waiting to happen.

There is a material element sign. Sn it stands for TIN

When aluminum is PLATED with TIN the tin prevents aluminum oxide from forming on the Al Cu interface.

Electricians, worth more than five dollars an hour know how to visually, read that CAREFULLY inspect the Al Cu interface and if the slightest trace of aluminum oxide has formed the termination must be replaced with a new one.

Aluminum oxide is one of the worlds best electrical insulators.

Electrical contractors are so paranoid about this, they insist on using incredibly overpriced COSMOLINE sold as balderdash miracle slop.

Set screw terminations WILL loosen if vibration strikes a nasty chord with heating and cooling.

Squeezing. "Crimping" is the second best way to join copper electrical conductors to copper terminations. Sn Tin is used to delay (NOT PREVENT!) inevitable oxidation of Cu or Sn.

I squeezed 330 MCM terminations then soldered them and used SBC Cable Communications grade triple wall heat shrink tubing over pure lead coating on the copper lugs. 316 stainless bolts, nuts, and fasteners were used to attach the TWO HOLE 350 MCM terminations to the cell flag connectors. 22-years later they are like brand new. Corrosion sealant was used. The T&B terminations were insanely expensive even 22 years ago. The terminations will outlive the batteries and consume 0.000% maintenance time or expense over a 30 year period. I have a strong fetish against the demand of surprise emergency "re-work".

[MEXICOWANDERER]

Forty bucks will get you a pentagon or octagon die hydraulic crimper on eBray. You'll never see a high amperage HV transmission line made with a dimple crimp. Medium voltage 250 MCM Al line has eight strands. A very different environment.

Go with the "eleven die" eBray crimper. Most offer free shipping and the pump lies on the ground giving you one free hand to retain the conductor.

Hard copper pipe is not nearly as pure as electrolytic copper. And heavy duty grade lugs have three times as thick Sn (tin) plating as cheap thin lugs. Cast copper lugs are by far the best bet. That and triple-wall heat shrink cable tubing. Anti-rotation style CAST lugs always gave me the best service. Go to Delcity.net and start searching. BTW, for some reason one size larger lugs fit much better when using AWG rather than SAE grade wire. So buy 2/0 lugs for 1/0 AWG cable.

[2oldman]

Many years ago I used these. Easy peasy, no corrosion, no heat. That is 4/0 cable. Ace Hardware I believe- just attach with an Allen wrench. Of course I was given dire warnings about Al/Cu connections and the things coming loose. Both turned out to be false.

I don't sweat connections and wire much anymore running 48vdc.