Ahhhhhggggggg!

[geekygrilli]

Put my repaired controller in the car, wired it up, all readings A-OK .
Turned everything right down, and it runs fine
Slowly ramped everything up over a series of runs, seeing what each variable actually changes in the car, and its all brilliant, getting a good feel for what it can do.
Doing a lot of stopping and starting so the controller got a bit warm, up to 70 degrees (no cooling in place). So I stopped fiddling with the settings and let it cool. Not a problem. Its all good, i'm happy.

Took the motor current up to a max of 350A, which is good for 25mph in 4th. Motor voltage reading goes to max of 37v, but I still need to go through some setting, surely it should go up to 96V??

Anyway, its doing OK.
Three cheers, yay!

Then i go to adjust the potentiometer and dropped my spanner so it touched btwm the Motor Negative (M1) and the positive of the potentiometer. Spark

The console went blank and the diagnostic LED starts flashing

If I disconnect the potentiometer I get no fault codes flashing on the LED, which is good, I think, I hope, I prey. But even with the potentiometer disconnected the colsole doesn't light up.
If I have the pot disconnected i can still trigger the forward contactor by pressing teh microswitch in teh 'throttle body'.

So I guess I have blown the potetiometer, not a problem, easy to fix, but I have probably blown the console too, which at £250 is a bit of a concern.

Worst case is that I have blown the controller, but only teh low voltage/current side of things.

Any one got any experience on this? I'll be calling Electrofit Zapi first thing in the morning, but if someone can offer advice in the mean time I might be able to sleep tonight!

Cheers

Chris

[geekygrilli]

I know for a fact that the potentiometer is not right, values are all over the place...

[electricvehicles]

Dont worry --- chill out with a glass of wine. Do you want me to lend you my programmer ? But pls dont blow it up
Would keep a bit quite about going on about the programmer. Michael from Electrofit Zapi might just pop in

[geekygrilli]

Thanks for the offer, but I'll see how it goes with EZ tomorrow. They must sort of know the consequences of what I have done, so should be able to say whats wrong.

In the mean time, if I can get a short travel dash pot, I should be able to check the controller is still working OK.

Hmm, i need to adjust/re-make my throttle body any way; its spot on for the throw vs travel, but leaves no room for pedal travel play. So re-making with a linear travel pot would be OK....might be easier to find.

Gonna go home and have my glass of wine now!

[aminorjourney]

You have my sympathy. I'm sure every EV owner has dropped a tool or shorted out something accidentally. We only do it once though

If you look at the Curtis site and download one of their manuals it's got a really good method of bench-testing your controller before you even put it in the car to get an idea of what is working and what isn't

In the meantime perhaps some insulated tools are in order?

*Grins and runs away*

*I did a similar thing a few months back with a shunt*

[electricvehicles]

Rubber spanners -- they keep slipping off the nut, and when I dropped one it bounced into the neighbours garden

[qdos]

Don't be silly rubber spanners would be no use to anyone. Now Rubber Batteries that's a much more sensible idea !

[geekygrilli]

Came in this morning, no fairies or pixies have been hard at work fixing it over night

[EVguru]

Everybody is going to drop tools.

From now on you will only ever use tools with insulated handles!

Buy some cheap combination spanners of the appropriate AF sizes and cut them in half so they're not long enough to create a short between battery posts. It will also stop you applying too much torque to terminal bolts. Get some adhesive heatshrink tube and insulate the handles. Keep them in your EV toolkit and don't use them for anything else.

I've managed to avoid any such incidents, but working on vehicles up to 288 volt nominal will keep you on your toes. Know when to quit; Like not testing the 288 volt system when you've been up to 3am working on it.

Cover terminals up! Once the car is on the road (if not earlier) put covers and guards on. Put your wiring in conduit. Make everything look neat and well thought out.

THIS IS A RANT ON BEHALF OF THE SOCIETY TO ABOLISH TRAVELLING SCIENCE PROJECTS!

Took the motor current up to a max of 350A, which is good for 25mph in 4th. Motor voltage reading goes to max of 37v, but I still need to go through some setting, surely it should go up to 96V??

Well, when you've got the controller fixed, try driving in a LOWER gear!

It's no wonder your controller is getting hot, you've got it permenently in current limit.

R = V / I

Thefore dynamic resistance of the motor at the speed you were running it is 37 Volt/350 Amp = ~0.1 ohm.

I = V / R

If you had 96 volt on the motor; 90 Volt / 0.1 Ohm = 960 Amp!

To limit the current to 350 Amp the controller is limiting the PWM duty cycle (motor voltage). Set if the motor current as high as it will go and learn which gear to use. Do a quick calculation for motor rpm in different gears at different speeds. I'd limit motor rpm to about 5500.

For a pot, I use one of these; http://uk.farnell.com/jsp/Passive+Compo ... ku=7006457

I then use an arm, drum, or snail cam on the shaft as appropriate. The original equipment off the vehicle can often be used.

[geekygrilli]

Sorry - I wasn't clear, at 25mph in 4th it was pulling 58 - 65Amps, not 350Amps.

350Amps was peak.

I now understand that the motor voltage was low because I had the 'Cutback Speeds' set very low.

Yeah, I know about the insulation on everything, and its no excuse, I was just trying to prove it works. No short cuts from now on!

My car will not be a 'travelling science project', I promise. It has to be an advertisement for EVs. It can't be qwerky and it will be completely user friendly - just like a normal car.

And also, you are right about seperate tool kits - I have my 'site tools', 'workshop tools', 'karting tools' and i will now buy a set of 'EV' tools.

Will order the pot now, thanks for the link.

I don't mind looking stupid and making mistakes, as long as I learn from them and it doesn't happen again. I'm bound to make mistakes along the way, and I am fully prepared for it.

Anyway - thanks for everyone's help and advice, it is very much appreciated.