[10.23.19]  Repairing a Chargepoint EVSE

I was gifted a faulty chargepoint for excellent reverse engineering and repairing. 

Conclusion Image Directory

Some Project Background

Lets take a look at the insides of this beast
Starting off, I didnt have the cover that should normally be sitting covering up the base of the unit but that realy wasnt a worry. On the left side there's a mains connection of 208-240 VAC, reccomending at least 10 awg stranded cable. Otherwise the user interface is literally a vacuum flourescent display, a pushbutton and two indicator lights.
Some more details, unclear if they will be useful, a provisioning password for the chargepoint EVSE, and some model / serial # information.
As this unit doesnt power on when fed 220v AC, but when you look at an off-angle you can see the character sub-displays that are part of the VFD display.  Its nominally a 16x2 display, but probably can do some minimal graphics. VFD's seem like an odd choice at first, but they are actually a really neat technology, they dont seem to mind the cold as much and can work down to much colder temperatures than standard LCD character displays.
Taking a quick look at the back of the unit, its fairly simple, just a single cast part with plenty of accompanying spider webs. A scrubby brush was used to remove most of the leftover ants and spiders
The case rear is secured with 5x phillips screws with built in gasket-washers.
With the front facing cover removed, the whole unit is fairly empty. As an EVSE is nominally just a mechanism to aquire ~220vac, I really didnt expect much to be hiding in here. What I was impressed with was the individually labeled wires, each with a crimped on ferrule connector. This seems a rather manual assembly process, but, at least very organized. I believe these were gen-1 vintage so they could have been optimized at a later date.
Yep its a VFD. This particular one is a noritake itron,
The random red wires were a bit curious.
Time to do some debugging. This large 5v 'power blob' or self-contained board mount power supply provides all the logic power for the entire board. For the sake of
Fortunatley the part in question still existed, i ordere another (knowing this may happen again) and it arrived via digikey usps. Interestingly i had used
This isnt a proud image, but for the sake of testing I 'adapted' a standard 110vac plug to work with a 220v outlet.

High charge-rate plotting.

Sevcon Details



(There's other photos in the photo gallery)
Concluding Remarks:

If you have questions or comments, ask below or send over an email.
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Stay safe when working with electrons in aqueous / semi-aqueous environments. Also wear sunscreen, I'm not responsible for your newly aquired winter-farmers tan : ]

Rensselaer Polytechnic Institute 
Electrical & Electrical Power