Looking for recommendations for specific wire-to-board connector

Thread Starter

kramzar

Joined Mar 7, 2022
3
Hi!
I am currently in the process of designing a commercial EV charging station, and as part of that I need a method of connecting the thick input and output wires to the main PCB. The problem I found is that high current/large size connectors are both very expensive and hard to get in any decent quantity. I want to find a part thats reliable and where I wont have problems sourcing the component in 2 years time if I need some more of them.

I found some decent stuff like 2604-3505 from Wago and some other stuff from Phoenix contact, but they are hard to get in big quantities and very expensive (8$ a piece).

My question is if you have made any high current applications, what kind of connector have you used for it?

The ideal connector i am looking for should have the folowing features:
Continious current rating of 32A+
5 pole
can accomodate wires between 2.5mm(14AWG) to 6mm(10AWG)
Preferably tool-les or clamp cage mechanism, since that would make the electricians life easier, but thats not a most have.
Pitch between pins of at least 7.5mm to comply with trace width/clearance requirements

If anyone with experiance would share some knowledge with us that would be highly apprechiated.
 

SamR

Joined Mar 19, 2019
4,194
Here in the US when I needed industrial quality electrical power connectors and switchgear, I mainly used Square D, Cutler-Hammer and Allen-Bradley. For ideas I kept a current Grainger catalog on my bookshelf. Those are for power handling, not PCBs.
 

Ya’akov

Joined Jan 27, 2019
5,663
Andersen Powerpole connectors are a possibility. If you are not familiar with them they are modular, polarized connectors designed for high currents. The housings, available in many colors, dovetail to allow arbitrary configurations. There are a lot options, but here's a representative group.

The PCB terminal is simple, and doesn't require its own housing because in use it is covered by the mating connector housing. In that housing is the terminal. The wire range available in the wire terminals is quite wide. They have purpose-made crimpers for termination.

I think they might even have SMD versions.

1646649037311.png1646648940405.png1646648991660.png
 

MisterBill2

Joined Jan 23, 2018
11,880
My experience with high currents connecting to printed circuits is a tale of grief. At that job the circuit boards had been designed by another who was gone before I was hired. So I had no chance to change the design.
The deadly result was that while nothing burned or melted, the voltage drops at full current met that nothing stayed within specifications.
So prior to accepting the choice of any connector type, verify the voltage drop through the mated pair at the anticipated load current.
There is one widely available brand of connectors that I will ALWAYS AVOID for any application that needs to be reliable. That name is available to those who need to know, by a PM to me.
 

bassbindevil

Joined Jan 23, 2014
422

MisterBill2

Joined Jan 23, 2018
11,880
Tell us a bit more about the application, and the actual current. 72 amps through a component lead that looks to be about the cross section of #14 wire, or possibly #12 wire, is beyond reasonable. OR it might be a few microseconds to drive a laser for a pulse.
 

Thread Starter

kramzar

Joined Mar 7, 2022
3
Tell us a bit more about the application, and the actual current. 72 amps through a component lead that looks to be about the cross section of #14 wire, or possibly #12 wire, is beyond reasonable. OR it might be a few microseconds to drive a laser for a pulse.
I probably made a typo. The current that is planed to be used is going to be between 16 and 32A, not more. This will also be continious current, that flows for multiple hours at a time. I have alredy done the testing and found out there is no significant heating on the PCB, since the traces are only 4cm long and very thick. I now just need a connector that would make installation easier for an electrician, since an electricians hourly rate is almost as much as the whole product itself.
 

Thread Starter

kramzar

Joined Mar 7, 2022
3
My first inclination is to suggest barrier terminal strips with through-hole leads. Connections are made with ring or fork terminals. But maybe those are too expensive. Keystone has screw terminals that mount directly to the PCB, up to 30 amp rating:
https://www.keyelco.com/category.cf...30-Amp-Screw-Terminals/p/476/id/477/c_id/1258
Or there should be threaded inserts that can be pressed and soldered into the PCB. Like these:
https://www.inserco.eu/en/broaching-inserts-ipcbricbfhiscbr/
wow I didnt know this exists, very usefull things. Sadly I wont be able to use them for this application since I am guesing you cant use them with hard-gauge wires. And most residential instalations use those for connecting their charging stations instead of soft wires.
 

MisterBill2

Joined Jan 23, 2018
11,880
One concern with the terminal solder connection to the PCB trace is that if the terminal body is not adequately restrained by the insulator, the torque of tightening the connection screw will shear the solder connection. That leaves a high resistance joint subject to failure after a few hours, or minutes. That is most common with the terminals that have thin round posts..
 

kaindub

Joined Oct 28, 2019
95
Having experience in power electronics for many years, we never used pcb terminals for power for more than 6 amps. For amps you need, the terminals were part of the mechanical design of the enclosure. Any connection to the pcb for power or sensing were done by smaller wires connected to the main terminals.
 

Irving

Joined Jan 30, 2016
2,668
Anderson SB50 powerpoles, spade or 5mm ring fittings are my go to choices for 10 - 50A. For ring/fork fittings an M5 stud through PCB with a square profile to prevent rotation and locking nut then ring/fork retained by a second nut. I've also used these "Erni" terminals though they're about $4 each...

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