75A OpenEVSE - gorawen/open_evse GitHub Wiki
This is an example of a 75A EVSE built with the Open EVSE V4.0 DIY PCB (originally built with OpenEVSE Arduino Shield & Arduino).
This should not be attempted by anyone without the required skills and knowledge to work with high voltage.
Open EVSE is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
The Open EVSE relay output is 12VDC. To power the Coil of a high current contactor, one 240V AC relay with a 12VDC coil is used to power the 240V AC coil of the contactor.
NOTE: The Open EVSE control Board must be grounded to the EV/Earth Ground for the pilot to operate correctly.
Note: for full 75A Operation, wire this with #3 AWG Copper wire for the (2) hots (I used Red and Black), and a #6 THHN for Ground (I used Green) to a 100A circuit breaker, a good low cost source for #3 THHN is "StayOnline", see this link:
http://www.stayonline.com/600-volt-thhn.aspx
The pictures below show the unit using a 14-50 plug on a 10/3 SOOW cable, this was temporary as I tested and debugged the EVSE, I will update the pictures once I have it hard wired to the 100A breaker/wiring.
Also shown is the OpenEVSE Arduino shield & Ardunio, it has since been replaced with the OpenEVSE V4 thru-hole PCB, as it has much better noise immunity, I have also replaced the wiring between the OpenEVSE and the AdaFruit LCD display with shielded cable, the ground wire has been upsized (from #22 to #16) from the ground buss to the OpenEVSE module, I have installed (4) ferrite cores and an MOV as well. All of this was needed to get the EVSE reliable, it will be shown on the updated pictures.
| Totals | + shipping, misc connectors & nuts/bolts | $723.24 |
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iPhone app picture of my dual charger Model S, 75A OpenEVSE being used:










