# Zorched controller, but why?



## EVfun (Mar 14, 2010)

I don't know, but I think Ron still has a Z2k without a hairball for sale in the classifieds here and you would be a good candidate to buy it. I would very carefully clean up the hairball before trying to use it again, and look inside for obviously burned items. 

You should contact Manzanita Micro, who are currently building the Zilla, as they may be interested in doing a post-mortem to determine the cause. I have never seen such a thing on a Zilla, that looks like a Curtis failure. Even the 1 other Zilla that suffered a full on failure into a stalled motor didn't blow (that one was running over the rated maximum voltage.) Did you have a cooling system on the Zilla?


----------



## major (Apr 4, 2008)

What is the red #6 wire attached to B minus on Zilla?


----------



## major (Apr 4, 2008)

welder4u said:


> What would do this to this controller? Just wondered what y'all thought.


Hi weld,

Been lookin' at this for a while. 









The contactor and fuse are badly installed. It is possible the cause was outside the Zilla and the Zilla failure was a consequence. The flash pattern also looks suspicious. And why is the nut on B- still shiny?

Good luck,

major


----------



## EVfun (Mar 14, 2010)

While looking at this photo even more closely, I also don't see a transient voltage suppressor installed on the contactor. It is listed as required in the manual and leaving it off may damage the hairball contactor driver circuit (I don't understand why it wasn't built into the hairball.)

The Transzorb is 1.5KE24CA-T. According to page 3 and page 6 of the manual these must be installed and are "very important." The diode often shipped with an SW200 contactor is not a suitable substitute.


----------



## welder4u (Nov 30, 2010)

I did find out that the hairball had been switched a while back...what are the thoughts on that?


----------



## EVfun (Mar 14, 2010)

That shouldn't be a problem. I've swapped my 2 Hairballs between my 2 Zillas (a Z1k-LV and Z1k-HV.)

What voltage are you running and what where your settings. Can you connect to the hairball still? (not plugged into the controller)


----------



## Tesseract (Sep 27, 2008)

major said:


> The contactor and fuse are badly installed. It is possible the cause was outside the Zilla and the Zilla failure was a consequence. The flash pattern also looks suspicious. And why is the nut on B- still shiny?
> ...


Hey maj... I agree that the contactor and, especially, the fuse are badly installed, but even worse is the use of a single Albright SW200 (or even a Chinese knockoff - can't tell) to feed anything bigger than a Curtis 1221 or an Alltrax AXE7245... For a Z2K I would have used (4) EV200 contactors bussed together with big copper plates and put them inside a metal box myself...

That said, I believe the Zilla failed first, _then_ the contactor opened up into a short-circuit. The magnetic blowouts in the contactor ejected the plasma to the surrounding areas.

I am also curious about that one clean bolt... was it, perhaps, wrapped in insulating tape that was removed after the plasma event?


----------



## major (Apr 4, 2008)

Tesseract said:


> Hey maj... I agree that the contactor and, especially, the fuse are badly installed,........


Good morning Tess,

I often see this. I can't say it always fails, but it always bugs me. Thousands of dollars spent on the conversion. A $100+ fuse. And they won't spend $25 on a proper fuse block 

EVfun had an interesting question about the Zilla cooling. I'd like to get some answers....welder??? Was there a coolant loop? Regardless, I think the Zilla monitors internal temperature and cuts back/shuts down accordingly. But repeated thermal stress doing that ain't so good 

Regards,

major


----------



## Tesseract (Sep 27, 2008)

major said:


> ...I often see this. I can't say it always fails, but it always bugs me. Thousands of dollars spent on the conversion. A $100+ fuse. And they won't spend $25 on a proper fuse block


Yeah, same with the contactor... it's why we put them inside the controller - we more or less don't trust our customers to do the right thing... 

At any rate, the fuse becomes a "stressed member" when installed like that and repeated flexing from vibration will eventually cause the rivets holding the fiberglass body to loosen then out spills the sand that quenches the arc when it blows, then the fusing element cracks, and then you are stranded on the side of the road (and out a $100 fuse to boot).



major said:


> ... Regardless, I think the Zilla monitors internal temperature and cuts back/shuts down accordingly. But repeated thermal stress doing that ain't so good
> ...


I would also suspect a temperature problem, but on the opposite end of the scale... if the failure happened when the controller/ambient temperature were near freezing AND this controller is several years old, then the ESR of the capacitors might be 2-4x higher than at 25-30C. The high ESR results in a huge spike during IGBT turn-off and boom they go. This would be a likely culprit if the controller failed soon after pressing the throttle for the first time that day, especially if it was cold outside. Otherwise, not likely.


----------



## welder4u (Nov 30, 2010)

major said:


> Good morning Tess,
> 
> Thousands of dollars spent on the conversion. A $100+ fuse. And they won't spend $25 on a proper fuse block
> 
> ...


I agree but, sometimes the customer is willing to spend the money, but the conversion shop cheaps out the project for profit. I can't stand this kind of mentality. I can't say who the first conversion shop was, but I can tell you their in a number of lawsuits and their out of business. As far as the second shop well... I just can't say.

There was a coolant loop but I haven't checked the pump condition yet. The day of the melt down, The car was being auto crossed on a very hot day. Also the contactor still works but the points were vaporized still junk at this point , the zilla and hairball both bad , and now I'm wondering about the motor. The customer has not given me the go ahead yet to redo the car, so I'm kinda in the wait and see mode. Since he has been to 2 other shops before he's a little gun-shy which is understandable.


----------



## Salty9 (Jul 13, 2009)

Interesting post-mortem for anyone who cares about how his EV works.


----------



## piotrsko (Dec 9, 2007)

strikes me that the shiny bits show things were replaced AFTER the event especially since other persons unknown looked at it.


----------



## welder4u (Nov 30, 2010)

piotrsko said:


> strikes me that the shiny bits show things were replaced AFTER the event especially since other persons unknown looked at it.


Nothing was replaced after the event just disassembled. Some of the nuts and bolts were stainless and some weren't.


----------



## major (Apr 4, 2008)

welder4u said:


> I agree but, sometimes the customer is willing to spend the money, but the conversion shop cheaps out the project for profit. I can't stand this kind of mentality. I can't say who the first conversion shop was, but I can tell you their in a number of lawsuits and their out of business. As far as the second shop well... I just can't say.
> 
> There was a coolant loop but I haven't checked the pump condition yet. The day of the melt down, The car was being auto crossed on a very hot day. Also the contactor still works but the points were vaporized still junk at this point , the zilla and hairball both bad , and now I'm wondering about the motor. The customer has not given me the go ahead yet to redo the car, so I'm kinda in the wait and see mode. Since he has been to 2 other shops before he's a little gun-shy which is understandable.


Thanks for the info and history. What is that red wire on B- and why is that nut shiny?


----------



## welder4u (Nov 30, 2010)

major said:


> Thanks for the info and history. What is that red wire on B- and why is that nut shiny?


Don't know why the shiny appearance, maybe it was in a better shielded spot during the event or maybe someone wiped it off. Just don't know. The red & white tape is on a rubber hose, and is something I slip over connections to protect me and the component during removal around the batteries.


----------



## EVfun (Mar 14, 2010)

I'm going to drop a theory here. Most likely it is wrong either in details or in its entirety. 

There was no transient voltage suppressor on the SW200 and possibly making matters worse the SW200 wasn't one with a continuous rated coil. This damaged the driver in the hairball so the contactor turned on when the ignition switch was turned on. The sudden inrush is what messed up the controller. Perhaps a cap spewed or an IGBT turned on from the sharp rise. The operator, not the hairball, turned off the controller. The destruction of the contactor is to be expected when it is opened full load. It did its last job well.

It's just a guess.


----------



## major (Apr 4, 2008)

welder4u said:


> Don't know why the shiny appearance, maybe it was in a better shielded spot during the event or maybe someone wiped it off. Just don't know. The red & white tape is on a rubber hose, and is something I slip over connections to protect me and the component during removal around the batteries.


In the photo in post #4 there is a smaller ring terminal under the shiny nut on the B- Zilla terminal on top of the larger black 2/0 cable lug. That is crimped onto a red wire of about #6 gauge. What is the purpose of that red wire and to what is the other end connected? It concerns me when I see a red cable connected to a negative terminal.


----------

