# Did my controller fry?



## cricketo (Oct 4, 2018)

Fun stuff. So first of all, you should be able to diagnose a lot of stuff even with the fuse blown - controller's control circuitry isn't energized through the traction fuse, but rather through the smaller keyswitch fuse (assuming one is even present). Key it in, and see if it blinks anything.

Here is the 1239E manual for you : CURTIS 1232E MANUAL Pdf Download | ManualsLib

Lots of fuses on Ebay, just match the type for your holder / mounting, and make sure to get a fast acting one. Here is one for example Bussmann FWH-400A ( FWH400A ) 400Amp (400A ) 500V Fast Acting Fuse | eBay


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## SMS (Sep 4, 2021)

Thanks cricketo, 

Controller status LEDs flashed, Red-1, Yellow-1, Red-2, Yellow-4. Take that to mean it is error 14 which is a precharge fault. I would not expect it to precharge without the fuse, or am I mistaken?


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## cricketo (Oct 4, 2018)

Precharge fault makes sense in this context. Precharge is typically done via a resistor that's connected across the contactor, and goes through the traction fuse. In some cases there is no resistor, controller simply fires up the contactor and precharges the capacitor bank straight from the battery. Regardless of which it is, fuse will be needed to see if controller is unhappy about anything else. Before you do that though, measure the resistance between B+ and B- on the controller to rule out some nasty short circuit.

And look on the bright side - your controller is still alive, at least partially


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## SMS (Sep 4, 2021)

Thankfully B+ and B- have a resistance of 2.3Mohm. Now looking for ways on how to do a bit more bench testing on the controller. 

Not wanting to let the time go to waste also relocating the battery pack and changing the EV west throttle potentiometer for a Leaf accelerator pedal. Been years since I drove an old VW. Was quickly reminded on how often the throttle cables break. Going the full drive by wire route.


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## cricketo (Oct 4, 2018)

You don't need a fuse as beefy as your original one to run more diagnostics, as long as you don't fire up the traction under load. If you lift driving wheels off the ground, you will probably be okay with one as small as 50A. Lots of ways to safely improvise this. Also note that voltage ratings of fuses is mostly to deal with arcing.


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## SMS (Sep 4, 2021)

Good point. Had not thought of using a lower rated fuse. How about the battery pack? Have 44 CALB batteries. What if I only connected one?


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## cricketo (Oct 4, 2018)

One what ? You need a voltage above your undervoltage / controller minimum input. For 1239E it is 120V I believe.


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## MattsAwesomeStuff (Aug 10, 2017)

SMS said:


> Hi Gang, Have a 69 Ghia with an HPEVS AC51, 144V, and 1239e Curtis controller. Went on the Curtis website and they do not have a manual for this controller listed.


I don't know why so many people go with these controllers when there appears to be zero sales or manufacturer support for them... when that seems to be the biggest reason people bought them in the first place.


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## cricketo (Oct 4, 2018)

MattsAwesomeStuff said:


> I don't know why so many people go with these controllers when there appears to be zero sales or manufacturer support for them... when that seems to be the biggest reason people bought them in the first place.


HPEVS motors are typically sold as kits with Curtis controllers. They're supposed to be a bit easier to use that way in standard applications as HPEVS designed custom VCL to allow programming of basic parameters without a dedicated Curtis handheld or PC programmer. It's quite a pain once you go outside of that "standard" box though - I went back and forth with the dealer, HPEVS and Curtis for weeks over some throttle behavior, until finally Curtis referred me to another person at HPEVS who provided a custom firmware that fixed my issue.

Bottom line, there are advantages and disadvantages there. Certainly if I bought a motor separately, I likely would try to avoid Curtis or Sevcon.


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## SMS (Sep 4, 2021)

cricketo said:


> One what ?


Yeah, I should remember not to try and write something that sounds intelligent on my phone. Have taken the 44 battery pack apart testing and inspecting them all. Was thinking of connecting one battery to run some more tests on the controller. Thanks for reminding me that there is a voltage minimum.

Thinking the possible sources for the blown fuse are controller, motor, battery, HV cable, TPS. Going to test what I can and send the controller away to be tested. From what I have read the controller most often is fried as a result and not a cause of a traction fuse blowing.


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## cricketo (Oct 4, 2018)

I certainly have seen that - I had two Sevcon MOS90 getting fried along with the traction fuse being blown. Fuse was 300A and controller was rated at 600A, so my only theory was that sudden loss of load caused the MOSFET failure. Either way, once the fuse is replaced and the controller is happy about pre-charge, it should be able to self-report any other possible issues.


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## brian_ (Feb 7, 2017)

SMS said:


> Have taken the 44 battery pack apart testing and inspecting them all. Was thinking of connecting one battery to run some more tests on the controller.


It would help communication if you used standard terminology... those are 44 *cells*, and a set of cells connected together form a single battery.


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## SMS (Sep 4, 2021)

Thanks for the reminder. Makes more sense that way


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## richieadam (Nov 2, 2021)

Precharge fault makes sense in this context.

Precharge is typically done via a resistor that's connected across the contactor, and goes through the traction fuse.

In some cases there is no resistor, controller simply fires up the contactor and precharges the capacitor bank straight from the battery.

Regardless of which it is, fuse will be needed to see if controller is unhappy about anything else.

Before you do that though, measure the resistance between B+ and B- on the controller to rule out some nasty short circuit.

And look on the bright side - your controller is still alive, at least partially


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