EVSE Terminals

[TwistLock]

.... but knowing that Wago makes the same / similar product puts my mind at ease that these aren't some one-off's in an evolving model line - Thanks.

 

[brycenesbitt]

The case design of these doesn’t quite match the Wago brand

Amazon is swimming with clones of the Wago design: many of which are "UL listed" with the quotes being intentional.

 

[brycenesbitt]

Picked up a clients EVbox EVSE today (Benz version). The line terminals are push in. Seems a little sketchy for continuous use equip .. no?
There’s no wire range listed just says use 4awg.
I spoke with EVbox’s weak sauce support and they said stranded is fine to insert without ferrule, though they have no documentation about using smaller gauges than 4awg, other than to say “…the engineer said it should be fine”.

Ok, I'm an engineer: with experience in lifecycle failure analysis of PC boards.
What happens over time with heavy wires and PC board connectors is the solder starts to crack: at the PC board.
Eventually it looks like this:



For a brand with really solid everything look to Flo.

 

[wwhitney]

What happens over time with heavy wires and PC board connectors is the solder starts to crack: at the PC board.

Is that due to (a) mechanical effects (solder trying to restrain a heavy wire against vibration and so on) (b) thermal effects (from large magnitude current cycling) (c) other (d) one or more of the above?

Cheers, Wayne

 

[TwistLock]

... so, in other words, it will outlast a modern car.

 

[LarryFine]

Probably vibration. Soldered wires often break where the solder flow ends inside the insulation, too.

Most automotive and motorcycle electrical connections are crimped rather than soldered.

 

[TwistLock]

Now they’re saying Mercedes shouldn’t have put that sticker there as their Livo box says #6. They still say it is approved for #4. (In my mind Mercedes wouldn’t even be touching these other than to receive the shipments all packaged and branded from EVbox Poland).

I asked again for something in writing stating - ‘stranded is ok, #6 etc. is ok, that they are specifically addressing the Mercedes rebrand and not their Livo, and where & whom is providing this info’. They said ‘yes’ and agreed to send an email, but I'm not holding my breath.

I like the idea of using/splicing on a #6 pre-EVSE (in my case) thinking good area contact, heat sinking, and possibly higher compression than smaller gauges. I bent up some scrap #4 and it begins to worry me (in this application).

In these designs I’m curious if a ‘lever lock’ version provides any better compression or if the tang can still relax over time as the lever, maxed out, is still relying on remaining tang flex. Or if lever design has more to do with helping end/edge of tang to dig into wire to improve pull out resistance and both designs offer similar compression.

 

[brycenesbitt]

Is that due to (a) mechanical effects (solder trying to restrain a heavy wire against vibration and so on) (b) thermal effects (from large magnitude current cycling) (c) other (d) one or more of the above?

I chalk it up to mechanical vibration. In some high end applications we'd vibrate test new designs on a shaker table, and any sort of mechanical stress on through hole pines, or overly tall components, would always fail.

 

[Twisted sparky]

Spring loaded terminals are what the renewable energy industry is doing. It’s cheap and easy, not necessarily safe and durable. In one of my very first inspections of these terminals, in an inverter, I found 100% of the wires installed had several strands folded back, not inserted into the terminal. You can’t see them without pulling the wires out for a physical inspection. I started requiring ferrules immediately, and, recently, the inverter manufacturer has started recommending them as well. It’s a slow process so they don’t yet require them, but just a few more fires, and they will get the idea. Been trying to get them to use standard touch safe fuse holders, with screw terminals, but they are just interested in the cheapest way possible. With as many failures as we see in solar/renewables, it would be great if we could stop building everything to the bare minimum standards, and try actually hardening the grid. This speaks to training the workforce, and hiring highly skilled electricians as inspectors.

 

[LarryFine]

This speaks to training the workforce, and hiring highly skilled electricians as inspectors.

Definitely.

 

[jaggedben]

Spring loaded terminals are what the renewable energy industry is doing. It’s cheap and easy, not necessarily safe and durable. In one of my very first inspections of these terminals, in an inverter, I found 100% of the wires installed had several strands folded back, not inserted into the terminal. You can’t see them without pulling the wires out for a physical inspection. I started requiring ferrules immediately, and, recently, the inverter manufacturer has started recommending them as well. It’s a slow process so they don’t yet require them, but just a few more fires, and they will get the idea. Been trying to get them to use standard touch safe fuse holders, with screw terminals, but they are just interested in the cheapest way possible. With as many failures as we see in solar/renewables, it would be great if we could stop building everything to the bare minimum standards, and try actually hardening the grid. This speaks to training the workforce, and hiring highly skilled electricians as inspectors.

I thought in particular of one company, not the whole renewable energy industry, when I read this post. And although I've plenty of complaints about that company that fit within "cheap and easy instead of durable", I'd not experienced any problems with their spring terminals. I did once hear someone from that company justify using spring terminals by pointing out that almost no one uses a torque wrench, and spring terminals would always be in the right torque spec, so to speak. I hear that. If you ask me, training people get all the strands into the terminal is a bit more basic than training people to torque connections properly. The situation you found reflects more on the installer than the manufacturer in my opinion.

 

[wwhitney]

Spring loaded terminals are what the renewable energy industry is doing. It’s cheap and easy, not necessarily safe and durable. In one of my very first inspections of these terminals, in an inverter, I found 100% of the wires installed had several strands folded back, not inserted into the terminal. You can’t see them without pulling the wires out for a physical inspection. I started requiring ferrules immediately

"Requiring" because you're the specifier? Or requiring as the inspector for the AHJ? If the AHJ has only adopted the NEC, I don't see how you could require ferrules because one job had an incompetent installer misuse the product.

Cheers, Wayne

 

[Todd0x1]

Spring loaded terminals are what the renewable energy industry is doing. It’s cheap and easy, not necessarily safe and durable. In one of my very first inspections of these terminals, in an inverter, I found 100% of the wires installed had several strands folded back, not inserted into the terminal. You can’t see them without pulling the wires out for a physical inspection. I started requiring ferrules immediately, and, recently, the inverter manufacturer has started recommending them as well. It’s a slow process so they don’t yet require them, but just a few more fires, and they will get the idea. Been trying to get them to use standard touch safe fuse holders, with screw terminals, but they are just interested in the cheapest way possible. With as many failures as we see in solar/renewables, it would be great if we could stop building everything to the bare minimum standards, and try actually hardening the grid. This speaks to training the workforce, and hiring highly skilled electricians as inspectors.

This is 100% on the installers, can't blame a product for shoddy work. I have PTSD from some of the stuff I have seen solar installers do....

 

[jaggedben]

This is 100% on the installers, can't blame a product for shoddy work. I have PTSD from some of the stuff I have seen solar installers do....

Let's be fair, I can say the same for ECs.