What's this blade-style connector? - Page 1
Forum section: electronics / projects

author: pstemari
author_rank: Contributor
timestamp: October 16, 2011, 08:22:00 pm
content: I'm looking at a MeanWell power supply,http://www.meanwell.com/search/SE-1000/SE-1000-spec.pdf,and the output voltage is on two humongous blades/lugs sticking out of the end. Anyone have any idea what those are supposed to connect to?The next cheapest supply with this rating is $140 more expensive, and I'd like to avoid paying that much just to get a set of normal screw terminals. These things look like they'd be nearly impossible to safely insulate without the appropriate mounting fixture.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 16, 2011, 08:31:00 pm
content: They're just bars with holes in, which you bolt through (M8 I think) and use standard crimp terminals to connect to the bolts.

author: Lightages
author_rank: Unknown
timestamp: October 16, 2011, 08:32:47 pm
content: The reason these have these bars instead of screw terminals is because the 5V power supply can output 150A! The bars are there to handle the current.

author: pstemari
author_rank: Contributor
timestamp: October 16, 2011, 10:18:48 pm
content: Thenext model uphas civilized blocks with screws, not these uninsulated bars sticking 1.5" out of the chassis. You're right, though, the model with the screws only goes down to 12v/60A.I wouldn't mind so much if they weren't so long. I suppose I can make a plastic sleeve or just put some heat shrink over them.

author: IanB
author_rank: Super Contributor
timestamp: October 16, 2011, 11:28:02 pm
content: I'm sure that power supply is designed for fixed installation. It's not a free standing bench supply.

author: Psi
author_rank: Super Contributor
timestamp: October 17, 2011, 03:45:20 am
content: Quote from: IanB on October 16, 2011, 11:28:02 pmYeah, the exposed mains terminals on the back seem to support that assessment

author: pstemari
author_rank: Contributor
timestamp: October 17, 2011, 05:03:36 pm
content: No, I'm looking at it to power the steppers for a CNC mill. Definitely needs to go in an outer enclosure, but the blades suggest that it's intended for some sort of slide-in chassis mount.Call me paranoid, but I don't like unshielded bare conductors, even inside a grounded enclosure.

author: Bored@Work
author_rank: Super Contributor
timestamp: October 17, 2011, 06:04:25 pm
content: You are making an issue out of something that isn't. Suitable nuts, bolts, washers and lugs crimped to beefy wires and you are done. Or if you want to do it in more style than necessary, bolt them to some suitable bus bars or braided strips.But seriously, why do you lament buying that power supply if you don't want it? And, are you sure you should attempt a build with a 1 kW power supply, taking your level of knowledge into account?

author: Jon Chandler
author_rank: Frequent Contributor
timestamp: October 17, 2011, 06:24:12 pm
content: For 150 amps you'll need at least AWG #3 wire, which is almost 0.25"/6mm in diameter. Going to take a pretty hefty terminal strip for that!

author: pstemari
author_rank: Contributor
timestamp: October 18, 2011, 05:21:25 am
content: QuoteYeah, from the size and length of the blades, I would expect a terminal block/socket designed for them to be something on the order of the sockets used for 240v/30A. Certainly not a JST connector!QuoteNo, just pulling 20A @ 48VDC, for which 12ga is fine. The more expensive model does have power factor correction, which is certainly a point in its favor, along with more normal terminals (copper blocks with clamp screws). The blades on the cheaper supply are far longer than needed to attach lugs or even bus-bars, which is why I asked if there's some sort of terminal block or socket that they're intended to slide into.As far design goes, I've plenty of experience in knowing what decently protected power circuitry looks like. Yes, it needs an outside enclosure, but good internal design doesn't leave large bare conductors in close proximity where a stray fastener, etc, can cause a serious short. Breaker panels have big bus-bars in them, but they're also shielded and the blades on the breakers slide into proper contacts.Given the amount of metal chips that go flying from a mill in operation, ranging from tiny needles or glitter-like flakes to spaghetti-like chips 3-6" long, you need a good enclosure, filters to keep the crap out, and a design that won't self-destruct if something does get in. Heat-shrink can cover the blades, but if there's some sort of terminal or power distribution block they're intended to slide into, that would be better. The steppers are all well-protected and draw about 5 amps each, and they get fed from a Gecko driver that handles current sensing, speed control, etc.

author: PetrosA
author_rank: Frequent Contributor
timestamp: October 18, 2011, 12:38:01 pm
content: Looking at the specs, my best guess would be that they have to use those strips to accommodate a range of lugs. You probably can't use the same lug for 12 AWG that you use for 2 AWG (you need the next size up, so at 90C that's a #2). It would make more sense if they included the range of lugs with the product or specified which lugs were designed (with the two stabilizing cleats) for use with the product.

author: sonicj
author_rank: Frequent Contributor
timestamp: October 19, 2011, 11:39:32 am
content: this is standard for high current dc equipment. those are the output rails brought directly out of the chassis for making low loss, high reliability connections to your lugs via nuts & bolts. its not a product designed for the masses, its a industrial product capable of bad things if necessary precautions aren't accounted for. if you need protection from flying chips or dropped tools, fab a cover, brush onLETor find some other product less stout.(photos are of high current DC motor controllers)

author: pstemari
author_rank: Contributor
timestamp: October 19, 2011, 05:18:46 pm
content: QuoteAbsolutely!! I definitely need a chip-proof outer case, internal insulation around the lugs, etc.Nice shots. Those lugs appear to be a good bit shorter than these.My two biggest concerns are conductive debris getting into the case and a screw inside the case coming loose. Dropping a tool while working on the electronics hot is another possibility. A well-designed socket would help with the first two, but if these are just intended for lugs, then other protective measures are needed. Insulated barrier between the lugs, coating the unnecessarily bare areas with some sort conformal coating or heatshrink, rigid plastic guards to slide over the extra lug length, etc.I suppose hoping for a socket to slide this into was wishful thinking on my part. There's a lot of little safety details engineered into everything things such as power outlets, etc. If a socket existed that took all the things I haven't thought of into account, that would be a very good thing.

author: sonicj
author_rank: Frequent Contributor
timestamp: October 20, 2011, 03:30:02 am
content: might want to check out Vicor & Lambda... i think they have some mostly sealed units.something else to consider is that heat dissipation can be equally as important as ingress protection. personally, i would just get whatever supply best fits your requirements on paper. the physical connections and perforated enclosures, etc. can be addressed with a little creative thinking.-sj