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View Full Version : Another wiring diagram looking for feedback - Please



furyphoto
04 December 2014, 2320
I posted this previously in my main build thread, but it quickly got buried.

Here is my V.1.0 diagram featuring 120vac household/240vac J1772 dual input charging, and Arduino powered Fingerprint Scanner ignition :cool:.

No BMS at the moment, I haven't decided on one yet, I'm considering doing my own Arduino powered very simple monitor for HV and LV cut and monitoring, no active balancing.

Let me know if you see any egregious errors (or tiny ones for that matter)

http://www.andrewdoran.com/_Services/proofs/ElMoto/HurricanE-wiring-v1-0.jpg

Stevo
04 December 2014, 2352
So... you only have 30 seconds to get your gloves on?!! LOL
Just kiddin, thats awesome!

frodus
05 December 2014, 1056
Fuse the input to all loads....

You fused the controller but you need to fuse the input to the dc-dc and the loads right after the 12v aux battery.

podolefsky
05 December 2014, 1250
You want KSI (Alltrax pin 1) to be switched. Right now the controller is going to be on all the time. Once the caps charge, there will be no current through the precharge resistor and KSI will see pack voltage.

I'd use a solid state relay to switch high voltage at KSI with low voltage from the DC/DC.

furyphoto
06 December 2014, 2322
Fuse the input to all loads....

You fused the controller but you need to fuse the input to the dc-dc and the loads right after the 12v aux battery.
I believe the DC - DC has a built in fuse on the input, but I will double check, thanks. Will definitely add a fuse to the battery, I totally missed that.

furyphoto
06 December 2014, 2334
You want KSI (Alltrax pin 1) to be switched. Right now the controller is going to be on all the time. Once the caps charge, there will be no current through the precharge resistor and KSI will see pack voltage.

I'd use a solid state relay to switch high voltage at KSI with low voltage from the DC/DC.
Noah, thanks for your feedback, I'm not sure I completely follow. I thought switching the KSI from the contactor would be sufficient to have the controller active while the HV system is armed. KSI is supposed to see pack voltage, no? Is it having KSI behind the precharge resistor that is the issue?

I will run solid state relays wherever practical, I will add one on the KSI if needed, I'm just not sure I understand why you are suggesting, it's my first controller experience.

podolefsky
07 December 2014, 1214
Yup, it's the resistor. When there is no current flowing through the resistor there is no voltage drop, so both sides will be at pack voltage. I'm pretty sure that will cause the controller to turn on.

If you didn't have the resistor it would work the way you drew it. But you need the resistor.

furyphoto
07 December 2014, 2147
Yup, it's the resistor. When there is no current flowing through the resistor there is no voltage drop, so both sides will be at pack voltage. I'm pretty sure that will cause the controller to turn on.

If you didn't have the resistor it would work the way you drew it. But you need the resistor.

Oh yeah, totally makes sense now. Not sure how i fumbled it, I guess i wasn't thinking of the resistor as a connection to both sides of the contactor, but of course it is. Thanks, Ill fix it.

furyphoto
07 December 2014, 2224
I'd use a solid state relay to switch high voltage at KSI with low voltage from the DC/DC.

Do happen to have an suggestion for an appropriate relay? I'm checking the data sheet for the controller now and looking, but all suggestions (if you happen to know a good source) are appreciated.

podolefsky
08 December 2014, 0843
I like the Crouzet GN84134850 (http://datasheet.octopart.com/84134850-Crouzet-datasheet-10542836.pdf). It's panel mount, opto isolated, very heavy duty. Has a nifty LED to let you know when it's on. Pricey though, about $80.

I also like the Panasonic AQ1AD2-3/28VDC (http://www3.panasonic.biz/ac/e_download/control/relay/solid-state/catalog/semi_eng_aq1.pdf). PCB mount, more compact and a lot cheaper, about $20. I've soldered wires to the pins and used them free standing with heavy duty double stick tape.

furyphoto
08 December 2014, 1315
I like the Crouzet GN84134850 (http://datasheet.octopart.com/84134850-Crouzet-datasheet-10542836.pdf). It's panel mount, opto isolated, very heavy duty. Has a nifty LED to let you know when it's on. Pricey though, about $80.

I also like the Panasonic AQ1AD2-3/28VDC (http://www3.panasonic.biz/ac/e_download/control/relay/solid-state/catalog/semi_eng_aq1.pdf). PCB mount, more compact and a lot cheaper, about $20. I've soldered wires to the pins and used them free standing with heavy duty double stick tape.


Both quite similar to generic ones I found, Thanks. I think I would feel safer with a name brand components for a bit more $$. Controller is one thing I definitely don't want to fail while on a ride.

I couldn't find any information for current load for the KSI on the AXE, so I am leaning towards one of the 10A panel mount ones. I also found a 2A and 5A PCB mount SSR's on Arduino breakout boards that I could incorporate into my control system.

I guess I need to dig a bit deeper for KSI current, I can't imagine it's very high, but I want to make sure I have it safely covered.



EDIT: LOL. Now, since I spent an hour searching for SSR's online last night, the Interweb gods are serving me SSR ads galore as I browse Elmoto. Google needs to get to work on some 'Precog' ad servers to save me some time!

frodus
08 December 2014, 1320
Those are way too spendy. Get a tyco KUEP-3D15-12. 150vdc contacts and 12v coil.

https://www.verical.com/partID/873658?&utm_source=octopart&utm_medium=buynow&utm_campaign=octopart

You can find them cheaper elsewhere, but it's a widely used relay for evs that need a Ksi relay.

podolefsky
08 December 2014, 1335
The Panasonic I recommend is $20. Plenty of current handling for KSI.

frodus
08 December 2014, 1458
As I said... You can find cheaper if you look.. Cheaper than 20 bucks.
http://www.eiamerican.com/product-p/KUEP-3D15-12.htm

That's just one of many from octopart.com

These are the models I've been using for years and use standard sockets and are really robust.

Use what you want, but I don't really care for pcb mounted relays and solder connections if I can avoid them.

furyphoto
08 December 2014, 1552
Doing a bit more thinking, I realized that my DC-DC is in the same situation, always seeing current.

What about switching the precharge resistor as part of the startup sequence? I would automate it, with a timer to precharge, then close the main contactor. That way the controller and DC-DC are completely disconnected when the bike is off, so no fear of parasitic load mysteriously draining my pack.

Actually, I wouldn't need a timer, I can use a micro-controlled current sensor to ensure that the capacitors are charged before closing the main contactor. (now I'm thinking and typing at the same time, dangerous!)

I found a couple of instances of EV Car guys doing it this way (one guy using a 60w light bulb as a precharge resistor :confused:)

If you had to remember to do everything in the right sequence manually every time it would be a bad idea, but included as part of the electronic startup sequence seems easy enough.

podolefsky
08 December 2014, 2143
The relay Travis linked to will handle 10A. Assuming 72V pack, 375W, your DC-DC will draw about 5A battery side. That's a huge amount of power on a bike, expect more like 150W at most, which is about 2A.

Either way, that relay should be able to switch both KSI and the DC-DC input.

frodus
09 December 2014, 0814
Yes it's only abouy 2A steady state.... But don't forget inrush current for the dc-dc capacitors and if he's using it for precharge. That current can be many times that 2A.

He can use the kuep relay for precharge and dc-dc that goes on when you turn the bike ok and then then another one for ksi that operates with the engine start button and self latches. Make sure to order relays with multiple sets of contacts.

podolefsky
09 December 2014, 0911
Now that I think about it, I don't think you need to use the relay on the DC/DC converter. Leave it connected to the pre-charge resistor as you have it. With everything off, the draw with the resistor in series is going to be tiny, a few mA at most. Less than the self-discharge rate. It will keep the DC/DC caps charged so you don't have a big inrush when the contactor closes.

If you are worried about discharge during extended storage, you should disconnect the battery. Either use a manual disconnect, take off one of the battery cables, or remove the main fuse. You should also store the cells at about 50% SOC.

furyphoto
09 December 2014, 1003
Thanks for the input guys, I will do a bit of thinking as to how I will end up doing it. I do like the idea that off is OFF, as in nothing drawing any load at all, but maybe that's just unfounded paranoia. I can always do some idle current draw measurements after the system is together so I know what the resting draw is. I will have a disconnect for long term storage (pretty much Nov - May around here) but winter is the time for rebuilds and upgrades anyway.

I heard back form Alltrax, they said the max current draw on KSI is 200mA so a small PC mount SSR should do it no problem. It seems like the easiest solution is to simply trigger that relay with the same circuit that closes the contactor.

podolefsky
09 December 2014, 1054
I get the concern, but the current draw really is going to be imperceptibly small. It will take years to drain the battery, like I said longer than the self discharge rate.

The Panasonic SSR I linked to is pretty robust with size pins. It's not a tiny PC mount IC. I always cover the joints in adhesive heatshrink and strain relieve the wires, and I'm not concerned. I wish there was an appropriate relay that size and price with wires, tabs or screws, but I haven't found one.

The main reason I use SSRs is because the input current is very small, so you can drive them with a signal level output (which you will find on some BMS). The coil on the 12V KUEP takes 100mA, which is probably fine but you'd need to be sure. Some signal level outputs have a limit less than 100mA.

furyphoto
09 December 2014, 1359
I've ordered an IC SSR breakout board, the relay on there is not rated for DC volts (240ac) but the Panasonic one has the same pin layout, so I will swap out the relay, and use 5v logic level to trigger it with the arduino. Since the KSI is only 200mA I'll run the less bulky PC version. The panel mount one at 10a is significant overkill.