Connectors for high current, low voltage - Page 1
Forum section: electronics / projects

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 27, 2018, 03:44:58 am
content: What sort of connector is recommended for high current and low voltage? Something like up to 250A and up to 12V, but not both at once. The connector should also be easy to connect and disconnect without tools (not when live), be resistant to accidental disconnection, be commonly available from electrical or electronics suppliers, and not be unreasonably bulky. Cost is not an issue as long as it's reasonable. Use case is for testing high current voltage regulators.To give you an idea, the following connectors I looked at but have fallen short of requirements:350A Anderson Powerpole - too hard to unplug. (Disconnect force rated at about 30 lbs would easily send stuff flying when the connector gives way.)10mm R/C bullet connector - too easy to disconnect? (Not sure since I haven't worked with those.)400A Camlock - too bulky (Found one that was about 6" long - having a foot of bench space taken up by the connectors is a bit much.)

author: Berni
author_rank: Super Contributor
timestamp: September 27, 2018, 05:11:03 am
content: Welders have some special high current connectors that twist lock instead of just sticking in.

author: Bratster
author_rank: Frequent Contributor
timestamp: September 27, 2018, 06:13:59 am
content: I think a welding connector would probably be your best bet as well.now you got the fun of choosing which kind as it seems like there are a ton of different styles.Dinse, tweco, lenco just to name a few.Sent from my Fi Moto x4 using Tapatalk

author: drussell
author_rank: Super Contributor
timestamp: September 27, 2018, 07:00:20 am
content: Are you looking for single conductor connectors or dual? (or more)Also, wire-to-wire, or is one side being mounted on a chassis?Take a look at Anderson connectors which are very commonly used on things like battery pack disconnects (the SB series) and are available in a wide range of sizes / capacities. Specifically, take a look at these two series which are available in versions covering your desired current range:Powerpole:SB:

author: Wolfram
author_rank: Frequent Contributor
timestamp: September 27, 2018, 08:48:02 am
content: How about Amphenol SurLok Plus connectors? Here's an overview of the available ones:https://www.mouser.fr/datasheet/2/18/SurLok%20Plus%20Brochure-1283892.pdf.

author: nctnico
author_rank: Super Contributor
timestamp: September 27, 2018, 10:00:49 am
content: How about using large binding posts? This one is rated for 200A:https://nl.rs-online.com/web/p/terminal-posts/7531788/Wurth has quick-disconnect high power connectors as well.

author: drussell
author_rank: Super Contributor
timestamp: September 27, 2018, 10:48:35 am
content: Quote from: NiHaoMike on September 27, 2018, 03:44:58 amI hadn't realized you had already mentioned these when I went looking for the connectors I was thinking about since I didn't know what they were called, just that they were available at my local industrial electronics store and had to go looking on their website to figure out what they were called.Perhaps one of the smaller ones than the 350A rated ones if you don't need that high of a current capability. I have never found the SB series to be excessively difficult to disconnect, even the big ones. Although I have never used the single Powerpole models, I believe they all the the same style of actual connector terminal.They are inexpensive, widely available and very robust. Even hot-plug capable as they have a sacrificial tip that is intended to take any abuse from arcing. Have you actually tried them or are you just looking at the specifications?

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 27, 2018, 01:06:06 pm
content: Quote from: Berni on September 27, 2018, 05:11:03 amThe Camlock is one of those, is there a list/comparison of other standard ones?Quote from: drussell on September 27, 2018, 07:00:20 amIt can either be one or two conductors, one conductor might actually be preferred if it helps keep disconnect force down.Wire to wire is preferred.Quote from: nctnico on September 27, 2018, 10:00:49 amNot much better than the screw lugs being used now. The point is to make it faster to swap boards.Quote from: drussell on September 27, 2018, 10:48:35 amI have used the 50A version of the SB Powerpole and it's a bit harder to disconnect than I like. I'm under the impression the bigger ones would be even harder to disconnect, is that not really true? The single Powerpoles can still be considered but I only have experience with the mini 15/30A version.

author: ConKbot
author_rank: Super Contributor
timestamp: September 27, 2018, 01:45:40 pm
content: Quote from: NiHaoMike on September 27, 2018, 01:06:06 pmThe larger ones do require more force, but compared to the cable size it isn't excessive. I've used them when operating an electric forklift, and with the large ones, you can get a grip on them with your hand, so it's a lot easier than if it were the same force with just your finger tips like the small ones. But then again who knows how many cycles those had on em, getting put on charge daily, or more if night shift needed them.If you want to test it before committing to buying a bunch and crimpers.https://powerwerx.com/dual-conductor-custom-cablepowerwerx can make you a custom cable. A SB350 with 1ft of red, 1 foot of black 2/0 AWG, with ring lugs for $50 each.

author: nctnico
author_rank: Super Contributor
timestamp: September 27, 2018, 01:53:39 pm
content: If this is for testing many boards then a test bed with spring loaded pins is the way to go. You can buy really high current test pins nowadays.

author: Jeroen3
author_rank: Super Contributor
timestamp: September 27, 2018, 02:14:25 pm
content: Those single pole twist and lock ones. These are isolated, but that's not always the case. They are easy to connect, but quite large.https://www.mscdirect.com/industrialtools/single-pole-receptacle-connector.htmlOtherwise just make something that you can push an eyelet on a contact plate with a toggle clamp.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 27, 2018, 11:57:02 pm
content: Found out they occasionally do testing at 125C in a thermal chamber, so any connector that relies on plastic to hold the contacts together would not be a good choice. I also found what was taking the majority of the time was getting all the strands into the terminal, so inverter lug pins are another choice and might end up being the best option.

author: edpalmer42
author_rank: Super Contributor
timestamp: September 28, 2018, 02:37:09 am
content: There are also Supercon connectors from Superior Electric. They're available with ratings up to 250A.If you search ebay, you'll find various items for sale.Ed

author: rounin
author_rank: Regular Contributor
timestamp: September 28, 2018, 05:07:11 am
content: Maybe radsok? Been wanting to try them.http://www.amphenol-industrial.com/images/catalogs/RADSOK.pdfNever used it, but they look nice. Otherwise I am an Anderson fan, but definitely have knocked stuff over trying to unplug the big ones. We have SB350s on a test cart front panel.

author: rounin
author_rank: Regular Contributor
timestamp: September 28, 2018, 05:09:50 am
content: Looks like radsok might be rated up to 125degC.

author: Jeroen3
author_rank: Super Contributor
timestamp: September 28, 2018, 11:01:02 am
content: Connectors you can mate at 125C will be a problem.I see harting has some connectors capable of a few hundres amps. Either in a housing, or separate plugs.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 28, 2018, 11:09:12 am
content: Big-ass bolt+lugs and an impact wrench?

author: amps
author_rank: Newbie
timestamp: September 28, 2018, 11:55:48 am
content: Two of these in parallel may be up to it:https://hobbyking.com/en_us/xt150-connectors-w-6mm-gold-connectors-red-black-5pairs-bag.html?___store=en_usThe 150A rating is a tad optimistic - they get pretty hot close to that current so I find using 40/60, not 60/40, solder helps to raise the melting point which seems to be their failure mode at high current. They're not locking, but you could solve that with a cable tie around the pair.They won't be suitable in your thermal chamber without substantial derating. Probably lugs and terminals are your best bet there, as Mike suggests.