I am making a project in which I am using the Arduino and Raspberry Pi as microcontrollers. I am also using some sensors and water pumps. There are six pumps, each sucking 15 watts maximum. At a time, a maximum of four will be on, and they are controlled via a relay module. I have decided to crimp my own wires for this project. Can you please help me with a few queries?
Should I use stranded or single core wires?
Is 22 gauge wire enough to power the relay and subsequent pumps?
I am using Dupont and JST connectors for connections to other sensors. Will 22-gauge wire be crimped to both of them easily?
If not, should I go with 24 gauge or 25 gauge?
Should I use silicone or PVC wires? Budget is not an issue.
So the current will be 18 Wt / 12 V = 1.5 A for each pump, 6A for all four. Note that starting current can be times more than nominal one.
According to the table, maximum amps for 22 AWG wire is about 1A for power transfer and 7A for chassis wiring. Your case is between this two. Therefore this wire can be used to power one pump, but is not suitable for all scheme powering. For all pumps and relays at the time you need something like 14-16 AWG wire.
The entire thing will be enclosed in a box of size 24x18x18 (lxbxh) (in inches) with ventilation, and the maximum amount of heat will be generated by the raspberry, which has a heatsink and active cooling. so we can assume operating temperatures to be almost room temperature. The hall of use is non-AC, so the room temperature will range between 10 and 40 degrees Celsius throughout the year.
Don't make your own wires. Premade duponts are made with specific fitting ratcheting dies that you simply cannot reliably duplicate by hand. For the cost of the proper tooling you can purchase thousands of premades, with better reliability.
Long term projects need terminal shields and power distribution systems.
If this project is a permanent installation rather than just a prototype that will not be used long term then I suggest that you do not use Dupont connectors
The environment, such as 6 pumps, may well cause such connections to come loose. You would be better advised to use soldered connections. locking plug and socket connections, IDC connectors or screw terminals for higher current connections
You are right but my runs will be longer than even the longest wires availible in my country, atleadt readily availible, and using multiple of them to make one run is not neat (the project is for show putposes) and also not that secure.
Thanks for the advice though
The project will not be in continous use, rather a show piece and may bd used once in a while. But i am using dupont connectors only for connections at the rasberry, sensors (they come with pins pre-installed) and breadborad as using others is not feasible there. All other connections are JST and screw terminals
All the more reason to use quality, secure connections. In my experience equipment that is used and then sits for weeks/months has a habit of being cantankerous when restarted.
But seriously, look close and you can see the connections are all screw terminals at the CPU end and grouped/shrouded duponts at the other. The cat used that project as a bed and never was able to break it.
You can pick that blob of wires by the CPU, and with all the components hanging free, it still runs and nothing disconnects. Try THAT with a breadboard and singleton duponts! LOL
Brother i too don't want to use singleton duponts, that is why I am making my own of the required number of pins. Secondly, the duponts are not that reliable connectors that is ehy i am using them in the rpi and sensors only (the area where i cannot change the connector). My primary connectors are jst and screw terminals only.
Screw terminals are the bomb. What do you use for power leads? I can't believe it, but my project is the only hit here for a search of power distribution!
Ganged duponts hold fine if there is no tension. But loose pins, not so much. What destroys single duponts is twisting. This springs the female connector, as well as rounding the male pin. This ruins the connectors the first time it happens. Ganging prevents rotation during insertion or use.
I find even triple or quad width duponts hard to hold, remove, and impossible to label.
If you have access to a 3d printer, shrouds help with retention, alignment, orientation, and labeling.
Look closely, and you can see the circular pin 1 indents at the wire side of the shrouds. The pin 1 end corners are also rounded so you can orient correctly by touch. The shrouds can be added without cutting the cables.
I have lots of free Arduino specific. 3D STL files on cults3d.com
I have other stuff so if you need something specific, lemme know.
Thanks a lot brother. Surely will let you know. And yes, i am using screw terminals for the power. Also because that the only option to fit 15 gauge wire properly.
