[Tremelune]

I'm at the point in my project where I'll need to start doing some high voltage re-wiring. I'm handy with crimpers and soldering irons, and I've worked with thick wiring for high-power 12V audio, but these orange high voltage wires are new to me...

My understanding is that high voltage wiring has different insulation (possibly surrounded by ground?). It's hard to find information, as "high voltage" usually means 1kW and above, whereas I'm working with a maximum of 400V in a Nissan Leaf pack.

- Can I use standard marine or auto wiring for 400V without degrading performance or increasing danger?

- Is there anything special about crimping or soldering HV wire I should know about?

- If I do need to buy wire and tools for this purpose, what's the good stuff? I usually buy marine-grade wire from Waytek for my stereos and what not.

- When is it okay not to wear my 1000V rubber gloves when working with these batteries? Though I've melted a wrench across a 12V battery, most issues there are avoided by disconnecting the ground and not touching any power terminals.

 

[x.l.r.8]

A good crimped connection is worth 100lbs of solder. I learned that the hard way on a mere 120v 100A. I used to boil solder in the connector and put the wire in until it wicked and thought that was as good as it gets, then I found out why they crimp from the factory. There are many crimpers with multi heads, hydraulic ones are expensive but for dependable connections you may think they are worth it. The ones you hammer I just don’t like the look of so I’ve never used one. If I still had my press I would make some dies to use that.

 

[Tremelune]

I did find some wire at EV West that should work:

https://www.evwest.com/catalog/index.php?cPath=2_21&osCsid=8p7e859sdm8bdm0bon08jfid66

Seems the "high" voltage stuff is just double-insulated and orange. If that's the only difference, it seems I should be able to use normal connectors and crimpers.

Can't say I understand the difference between the EV West cable, the Hew-Kabel cable, and Champlain EXRAD XLE cable...

 

[Tremelune]

Seriously, where are y'all buying your wiring from? EV West starts at like $5/foot. I can't find voltage specs on Waytek...

 

[Tremelune]

Should I even worry about this in a 400V max system?

https://www.anixter.com/en_us/resources/literature/wire-wisdom/insulation-levels.html

For cables rated 0 through 2,000 volts, the in-service voltage stress on the insulation is so low that the concept of insulation levels is largely unnecessary.

the operating voltage stress on a typical 600-volt cable is about 5 volts per mil of insulation thickness, i.e., each mil (0.001 inch) of insulation must withstand only 5 volts of electrical stress.

Seems like a 600V cable would need way less than a millimeter of insulation to avoid arcs...

 

[dedlast]

Should I even worry about this in a 400V max system?

Seems like a 600V cable would need way less than a millimeter of insulation to avoid arcs...

That's pretty much what I got out of it, too. It seems that if it's rated at 600V, you shouldn't have any worries about insulation in your application.


B

 

[Tremelune]

Actually, I might have botched the units...

1000V / 5V * 0.001in * 25.4 = 5.1mm

600V / 5V * 0.001in * 25.4 = 3.1mm

400V / 5V * 0.001in * 25.4 = 2.0mm

200V / 5V * 0.001in * 25.4 = 1.0mm

I just figure people are wiring up cars, I gotta wonder what they're using if not special EV West cable...

 

[piotrsko]

Well us Luddites from the dark ages used large gauge welding cable that has an insulation of about 1/8 inch, but I'm not sure of the upper voltage spec. It does function for 4 years @ about 400 volts, and I was pretty sure when I bought it that it was specified to 600v break down. It also WAS much cheaper than anything EVWEST.

 

[brian_]

This discussion reminds me of speaker cable. There's what functions safely and effectively, and there's what's sold for the purpose with a pretty cover in a specialty store. Ever heard of Monster Cable?

But seriously, appropriate insulation is important, and colour-coding consistently could be life-saving. The copper inside doesn't care about the voltage.

 

[Tremelune]

That's my point, though...Insulation is important, but I don't want to pay for Monster speaker cables when nearly any dirt-cheap zip chord will do...

The EV West cables are the Monster in this equation, and I'd rather get cheaper stuff from Waytek if the standard insulation is enough for a 400V system (which I suspect it is at x/0 sizes). If a roll of orange electrical tape saves me $100, that's cool...Failing that, maybe a source for cable that has less of a markup. EV West is great, but they're charging top dollar for the convenience, and I'm only sometimes willing to pay for it...

For automotive wiring, everyone assumes 12V, and so don't list insulation specs much...

 

[kennybobby]

did you not look up welding cable? it's generally very flexible in large gauges and the insulation is rated up to 2000 V in some cases. Go to any welding shop around town and look it over.
https://www.wireandcableyourway.com...ve&utm_term=4580496728918895&utm_content=soow

600V rating, orange, 1/0 gauge, $3.24/ ft. Shipping will be the killer, that's why you find it locally.

 

[brian_]

That's my point, though...Insulation is important, but I don't want to pay for Monster speaker cables when nearly any dirt-cheap zip chord will do...
...
For automotive wiring, everyone assumes 12V, and so don't list insulation specs much...

The specs for insulation that really matter in most cases are not directly about voltage isolation (dielectric strength and thickness), but are more about conditions: ability to withstand high temperature, resistance to damage by oils or solvents or ultraviolet light, cut resistance, etc.

I looked into real high voltage cable (e.g. 500 kV) when a transmission line was being built here and underground was suggested. Their big concern was cracking in the very thick insulation; insulation material to provide sufficient voltage isolation isn't a problem.

The suggestion of appropriately rated and coloured welding cable makes sense to me. My guess is that the cable linked above is probably used more for temporary AC power than for welding, but welding suppliers can be good sources of stuff use a lot of - I bought my angle grinder from one because there's at least one grinder on every welding truck and the welding supply store brought them in by the pallet load.

Flexibility in single-conductor cable is a function of both the insulation (thickness and material) and how finely stranded the conductor (assumed to be copper) is. For the same cable gauge, cable to wire a house has only a few strands, an automotive battery cable or RV power cord has lots of strands, and welding cable likely has many more so it can be moved around easily. Most cable in an EV doesn't need to be highly flexible because it doesn't move in use, but more flexible can be easier to install, and cables to parts which shift (rubber-mounted motor, for instance) need enough flexibility to avoid failure.

 

[Richter12x2]

The single conductor 2/0 welding cable is more intended for high amp welding processes like ARC and TIG. Voltage Max is less of a problem than Amperage, and unless you're going Salt Track land speed record racing, you won't be running at peak amperage for long enough to matter. Welders work in VERY extreme situations, like oil rigs at sea, etc. I wouldn't worry too much about what you're likely to encounter in a properly installed vehicle installation. It even comes in HV orange already.

I'll also say, I've seen situations where EV West, as good as they are, picks up something and then marks it up with no change. Don't get me wrong, they do good work, but I wouldn't want to pay the extra money that they paid some poor guy to rub the words "Welding wire" off their offical EV cables with nail polish remover if that's what they're doing.

 

[remy_martian]

If it's going on the road, you need to consider first responders.

There's a reason why only orange insulation is used on the HV side of an EV.

Them....

and an inadvertent mechanic or tow truck operator, for example.

Get in a car accident where you could survive and they're not going near an EV that does not have a disconnect or clearly designated HV wires that can be visually observed to be compromised. You bleed to death because you saved $300 in cable 🙄

The lead from the inverter to the motor needs to be shielded, as well. Otherwise, the neighbor's gunna get ticked that you're making her miss her soaps and will call the FCC on you if she figures out the source (there's a Futurama where Bender interferes with the TV and they trace it to him).

Brian already mentioned many of the qualification conditions for automotive that you won't find in welding cable (which is designed for flexibility - do you really want floppy cables that are being fatigue cycled over every pothole?). Do you want the car making hydrogen while you're fording 6 inches of water in a downpour that's overwhelming a storm drain? Insulation bursting into flames during a drag race on the street?

In any case, safety is not something you should be a cheap Charlie with, though I'm with you on finding EV cable for low cost.

EV West caters to Hollyweird types, so not exactly cheap in most things...they do have inventory, though, and having inventory increases prices.

Maybe we should do a "club" buy of a big spool of Orange Stuff on GroupGets?

 

[Richter12x2]

Say what you will, the 2/0 welding wire I just got from eBay at $80 for 25 feet is a lot sturdier stuff than the leads I harvested from the Nissan Leaf. The thing about welding wire vs EV wire, is EV wire is spec'd and rated for a specific purpose. I.e. "we know this run is 2 feet, and 0 gauge will handle those amps for a few seconds at a time so that's what we used" vs welding wire, where they have to be able to handle most conditions, because they don't know that you're not trying to highduty cycle MIG weld the leg on an oil derrick with 200 feet of cable in the rain.

Incidentally, flexibility in wire, especially thick cable, comes from strand count, and having a wire that's more flexible not only handles more current, but also is MORE resistant to fatigue cycling than wires with less strand count. Where you've installed it, if it's going to flex, it's going to flex.

 

[brian_]

Incidentally, flexibility in wire, especially thick cable, comes from strand count, and having a wire that's more flexible not only handles more current, but also is MORE resistant to fatigue cycling than wires with less strand count.

Yes, except that for the same cross-sectional area of copper, more strands makes no difference to current-handling ability. For the same overall diameter of wire bundle, more strands makes little difference to cross-sectional area of copper, (because packing density doesn't change much); the American Wire Gauge standard is based on cross-sectional area, so two cables of the same AWG have the same cross-sectional area (and thus the same current-carrying capacity) regardless of the strand count.

 

[Richter12x2]

Actually, I just had a look at the website: 2/0 AWG Cable - Orange, EV West - Electric Vehicle Parts, Components, EVSE Charging Stations, Electric Car Conversion Kits if you click on the link for manufacturer spec sheet, you'll see it's the spec sheet for welding cable. It's double-insulated, which isn't the same as shielded, but it's just welding cable where they paid to have their name on the jacket.

Again, nothing against them, and markup and California real estate, etc. etc. Markup is how you do business, and they've got bills too. It's definitely cooler to look under your hood and see "EVWEST" and not "Bubba's 2/0 Welding Wire". It's up to you to figure out if that's worth the extra $2 a foot to you, but it's just rebranded welding cable.

 

[brian_]

The cable with orange insulation is also, um, orange. Since that's the industry standard for high-voltage cables in electric vehicles, it's good to be orange, as remy martian explained. Since the welding cable is available in orange without the corporate logo and for a lower price that would likely be the better choice... but conveniently available welding cable is most commonly black.

A lot of what EV West does seems to be selling stuff that anyone could probably get, conveniently gathered in one supplier's web site.

 

[brian_]

It's definitely cooler to look under your hood and see "EVWEST" and not "Bubba's 2/0 Welding Wire".

Is it? I would take the second of those choices.

 

[Tremelune]

The EV West cables are Tryflex Welding Cable. They do mark up, but they also sell it pretty conveniently by the foot. If you want to buy from Trystar, I'd think you'd have to order a lot.

I also bought some cheap stuff that needed a smaller die to crimp securely, and the insulation wasn't as thick. This was pretty standard welding cable in the color orange...Since the Leaf 2AWG wire (maaaybe 0AWG), cheap 2/0 seems fine anyhow.

My main concern with "high" voltage cable was that it might jump through the insulation...This doesn't seem to be a real concern until you get well above a kilovolt [citation needed].