DIY Home EVSE

[W.Petefish]

Parts List Thus Far:
ModularEV Power's Control board
TucsonEV's J1772 Plug w/ 8 meter cord
Leviton 8895 GFCI
24v Power Supply
SSR 90A - On Order
Box From Home Depot (Breaker Panel)

 

[W.Petefish]

The SSRs arrived on monday and I put it together this evening and did an electronics test with the Roadster. It worked like a charm.

Sorry for the blurry images, I was in a hurry with low light.

 

[DarkStar]

The SSRs arrived on monday and I put it together this evening and did an electronics test with the Roadster.

Be sure to get some heatsinks on those SSRs, they heat up a lot! That's why EVSE manufacturers usually use contactors.

 

[W.Petefish]

I noticed some heating. I'll probably solve this using an aluminum buss bar for mounting w/ a heatsink on the end for thermal transfer.

I am using 90a SSRs which should handle the current just fine. I'll also think about upping the rating on the SSRs. (i.e. higher rating the less they heat up.)

 

[hcsharp]

I used 100A contactors because I assumed they were more efficient than SSRs. Although I notice the contactor heats up a little from the coil. The newer ones are generally more efficient. In my climate I have to leave the car plugged in a lot so the contactor is engaged for long hours consuming energy. I wonder if the SSRs are more efficient when the car is drawing only a small amount of power.

I noticed some heating. I'll probably solve this using an aluminum buss bar for mounting w/ a heatsink on the end for thermal transfer.

I am using 90a SSRs which should handle the current just fine. I'll also think about upping the rating on the SSRs. (i.e. higher rating the less they heat up.)

 

[W.Petefish]

I would think so, because the contactor draws more current than both of my SSRs. (which are wired in series)

Integrating the GFCI is proving to be a real pain, but is solved (for now) through a relay in line with the SSRs.

Working now on mounting everything. When thats done I'll disassemble it and take pictures of the final assembly. So far I can get everything in and have room to spare. I may also add in a Voltage and Current meters on the front.

 

[widodh]

Seriously, did you have to post this? I thought I'd be happy with buying a standard EVSE/charging station for my new house, but this thread gave me a bunch of new ideas

The board from ModularEV is seriously cool! Just bought a IEC62192-2-2 outlet on the web somewhere, I just have to build my own EVSE!

 

[W.Petefish]

I was unhappy with the wall-mount units. All of them look like gigantic eye-sores. The home of the future will have these things integrated into their walls and have high enough power to be able to charge an empty roadster in 4 hours.

I've started the fitting process, and have half of the components mounted. If this weather persists I might have it finished by this evening.

Question: Do ya'll think that I should add in a volt meter and an ammeter as well? (I have a pair for testing purposes.)

 

[vfx]

I was unhappy with the wall-mount units. All of them look like gigantic eye-sores. The home of the future will have these things integrated into their walls ...

Anyone here have the toilets that have the tank inside the wall? There are concerns about access.

 

[W.Petefish]

Anyone here have the toilets that have the tank inside the wall? There are concerns about access.

Its called tankless... my school does though.

 

[hcsharp]

...
Question: Do ya'll think that I should add in a volt meter and an ammeter as well? (I have a pair for testing purposes.)

I put a digital volt meter LCD in mine because I found a nice looking display for < $10. I have a separate LCD that displays lots of other information including amps corresponding to the pilot signal, but it has much smaller characters and you can't read it from across the garage. I may also have it display the actual amps the vehicle is drawing. I'm constantly updating my software! Frankly if doing it again I wouldn't use the separate voltage display. It's pretty (blue backlight) but ultimately just another energy drain and I can just as easily have it displayed on the programmable LCD, which BTW is a must-have on any DIY EVSE:wink:.

 

[Lloyd]

When you're done, how about posting a step by step DIY with a parts list?

 

[W.Petefish]

Here is the beta test version... Not quite finished, but able to test at full amperage.

 

[DarkStar]

What model of GFCI is that? I've seen those before but they've always been 120 volt versions, not 240. Thanks!

 

[W.Petefish]

The GFCI is a Leviton 8895. I am concerned as to the fact that the GFCI keeps tripping and shutting off the SSRs. I'll need some time to work through this problem.

I also verified that the Roadster hates any J1772 over 70A.

I noticed some heating from the SSRs. I'm also going to add a fan to help cool them.

 

[hcsharp]

...
I noticed some heating from the SSRs. I'm also going to add a fan to help cool them.

Do you still think the SSRs consume less power than modern contactors?

 

[W.Petefish]

Less. They use around, I think, 3-20mA where contactors use around 200mA and use AC rather than DC. (at least most)

 

[Fuzzylogic]

Nice project!

But...are you allowed to use SSRs instead of a Contactor/Relay?

I always thought the 240Volt live wires needed to be physically disconnected from the (J1772 or Tesla) plug, when not in use.
Although a SSR disconnects it electronically, i don't think it's as safe as a contactor.

 

[widodh]

Nice project!

But...are you allowed to use SSRs instead of a Contactor/Relay?

I always thought the 240Volt live wires needed to be physically disconn:ected from the (J1772 or Tesla) plug, when not in use.
Although a SSR disconnects it electronically, i don't think it's as safe as a contactor.

could be indeed! I remember reading something like that. Might be Europe specific.

I found a descent 4p relais: LEGR RELAIS 4P 4074 63A 24V - Magneetschakelaar, AC-schakelend - Relais/magneetschakelaars - Industrieel

That would work I

 

[W.Petefish]

In theory you don't even need a contactor/SSRs. (don't take my head off over this one) But I find that your breakers will wear out faster than you'd like, and it is great big shock hazard if you don't have them.

Mind you that this isn't UL approved or even rated. That being said I over-design the circuit so that it can handle even more amps than it'll ever see in any way, shape, or form. Like has been said, overkill is a good thing when it comes to electrical safety.