Alternatives to terminal blocks for frequent wiring connect/disconnect - Page 1
Forum section: electronics / projects

author: djsb
author_rank: Super Contributor
timestamp: November 23, 2019, 06:43:38 pm
content: Are there any alternatives to using terminal blocks (with screws) for FREQUENTLY connecting/disconnecting wires to a PCB. All the screw less connectors I've seen are only suitable for pushing a wire in ONCE. They can't be used for repeated re-wiring. WAGO terminals are very good, but they can't be PCB mounted, and they aren't available as individual poles. It would be nice if there was something available that could be used without a screwdriver as well. Does anyone know of anything suitable? Thanks.

author: kripton2035
author_rank: Super Contributor
timestamp: November 23, 2019, 06:55:18 pm
content: I use something like this one :https://www.banggood.com/2EDG-5_08mm-Pitch-4-Pin-Plug-in-Screw-Dupont-Cable-Terminal-Block-Connector-Right-Angle-p-1413070.htmlyou use the screwdriver only once.

author: Cerebus
author_rank: Super Contributor
timestamp: November 23, 2019, 08:06:10 pm
content: Take look at these connectors from Phoenix Contacthttps://www.phoenixcontact.com/online/portal/gb/?uri=pxc-oc-itemdetail:pid=1792216&library=gben&pcck=P-11-01-05&tab=1&selectedCategory=ALL.They have a locking level, push the wire in, flip the lever, done. PCB mounting natch.If that isn't exactly what you want, have a look around Phoenix Contact's catalogue, they have 1000s of PDB mounting terminal types.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 24, 2019, 06:21:01 am
content: I'm partial to pluggable terminal blocks, and the above spring-clamp kind are nice as well, especially convenient for industrial use.Also partial to making my own plugs, but I have the hardware for that (housings, terminals, crimp tool), YMMV.Tim

author: paul8f
author_rank: Regular Contributor
timestamp: November 24, 2019, 08:22:40 am
content: Just be aware that some cheap spring loaded clamp type connectors can lead to weak electrical connections, (especially over time if there is any type of vibration on the board.) A weak connection could mean a hot spot or a voltage drop in a high current circuit. The wires, even if tinned would also be prone to fraying and breaking off at the ends (think stereo speaker connections...)Would it be possible for you to run wiring from the terminal blocks out to a pluggable connector? Cumbersome, but it might be the better option in the end as it would be quick and easy to connect/disconnect, and you're guaranteed good connection every time.

author: Electro Detective
author_rank: Super Contributor
timestamp: November 24, 2019, 09:48:38 am
content: as abovebeat me to itSometimes if you need 'walk away' dependability, it's screwdriver time..

author: ConKbot
author_rank: Super Contributor
timestamp: November 25, 2019, 04:59:44 pm
content: Quote from: Electro Detective on November 24, 2019, 09:48:38 amSpring terminals with appropriate clamping force(i.e. Proper phoenix or similar connectors, not some un-named special) will be more reliable than screw terminals. High vibration environment? Always has tension, can't back off. End user tinned the stranded wire and put it in the terminal? Sping will move as the solder cold flows and doesn't lose tension like a screw terminal could. Takes a lot more creativity to over or under tighten it, etc.Both should be pretty reliable if done correctly, with good quality components. Spring clamp ones will be more variable with quality, screw will be more variable with use technique. If you control both, then its about a wash.

author: Cerebus
author_rank: Super Contributor
timestamp: November 25, 2019, 05:20:47 pm
content: Quote from: Electro Detective on November 24, 2019, 09:48:38 amThe OP, although he/she seems to have gone walkabout, said:Quote from: djsb on November 23, 2019, 06:43:38 pmSo this isn't for a 'walk away' application.Interesting the UK mains wiring codes require (or they did when I was intimately current with them) that screwed connections are 'inspectable', that is, aren't placed somewhere where you can walk away and forget them. They're expected to be inspected, and adjusted if necessary, at regular intervals. Generally for 'walk away' applications that could not be regularly inspected crimp connections (properly made, adequately stain relieved, etc. etc.) were preferred.

author: tunk
author_rank: Super Contributor
timestamp: November 25, 2019, 05:44:19 pm
content: Do a web search for this: KF141 terminal

author: jbb
author_rank: Super Contributor
timestamp: November 25, 2019, 07:37:45 pm
content: Quote from: djsb on November 23, 2019, 06:43:38 pmYou'll need to make some estimates here. Many pluggable contact systems are intended for maintenance & servicing, so have a life span of 20 - 50 cycles (you'll likely get more than that in practice). Check for 'lifespan' or 'service life' or similar on the data sheet.The Molex Micro-Fit connectors are quite nice, but you'll either need to fork out for a crimper (look for a technician crimper) or buy pre-crimped leads.I've had good results with Phoenix Contact in the past, for example using a part like this32 contact DFMC 1,5/16-ST-3,5-LR(see cataloghere). (I can't remember the exact part, it was a few years ago.) It's only rated for 25 cycles or so.If you needmanycycles, you'll need to look for a plug & socket instead of a pluggable connector...