At these points inside the distribution cabinets you can get or deliver electrical energy.
You can connect a wire from a distribution cabinet to your tent, vehicle, project or village if you are in range of the grid. At SHA2017 we are located here (map is at the bottom): https://wiki.sha2017.org/w/Cluster:AltPwr.Net Connect the wire for negative to a blue terminal block inside the cabinet. Connect the wire for positive to a circuit breaker. There are 4A and 16A breakers. Use thicker / shorter wire for lower losses. Please bring at least 25m of wire to the event. For a 4A connection, use 1.5mm2 to 6mm2 wire. For a 16A connection, 4mm2 to 16mm2 can be used. Using wire ferrules is recommended. If you are not certain how to connect your wire to the grid, we will help you.
The circuit breakers are DC rated types with a C curve characteristic. The tipping point in the breaking curve for those devices is 5 to 10 times nominal current. At this tipping point it will break magnetically instead of thermally. For a 4A breaker this means it will trip magnetically within 0.1 seconds at 40A or more. For a 16A breaker this is at 160A fault current. These breakers can handle triple rated current for about 5 seconds or more. So starting up a large device is not a problem. When a circuit breaker has tripped thermally it can take a while for it to cool down. Please wait a few minutes if the breaker does not want to stay in the on position. Also, be careful. They can get hot!
You can connect anything that can deliver DC power, just make sure you don’t go over 48V at the endpoint, this could result in a shutdown at 50V of the whole cabinet you’re connected to. There is a bunch of car headlights that light up between 48V and 50V to warn you and to dissipate some of the “unwanted” energy. Ideally we’d like to put that in batteries, but that’s for a next time maybe.
For energy generation ideas, visit the user projects page.
If you have a 12V or 24V battery setup, you can connect to the grid in various ways. It depends on your capacity to generate electricity. If you have none, no problem, just use the upper diagram on the picture below. If you have under-capacity (you use more than you generate and your battery is big enough), you too can use the setup in the upper diagram. If you have over capacity or a small battery (or none), the lower diagram is what you need to check out!
The lower diagram needs some explanation, the 14.4V to 48V DC-DC converter is a modified one!
This converter needs to start only when the input Voltage is above 14.4V. This can be easily achieved by adding a simple transistor circuit at the input. This circuit needs a connection to the feedback pin of the converter too. I will draw this schematic shortly.