(ET) DCP/Alltrax; Fw: death of a DCP raptor

["Christopher Meier" <mr23 mn rr com>]

FYI, for those of us considering the Alltrax Elec-trak controller...

Guess we ought to ask how much 'overhead' is built into the Elec-trak
version compared to the Raptor.  I'd like to be able to push it to 
nameplate ratings whenever I want or need; and the controller should
stay below it's programmed limits so that the 'overhead' isn't used up.
I don't want to be replacing controllers in my Elec-trak every so often.

Any comments on this, Steve?

----- Original Message ----- 
From: "Jim Coate" <jbc coate org>
To: <ev listproc sjsu edu>
Sent: Saturday, February 07, 2004 2:22 PM
Subject: death of a DCP raptor


> The short version is that I have now learned that even basic flooded GC 
> batteries can kill a big DCP Raptor, and that full support is no longer 
> provided for these controllers. So other DCP owners be warned & be nice 
> to your controllers!
> 
> So how did it happen? I have a 132 volt pack of US145s, powering a 
> Raptor 1200 with an ADC 9" (probably neutral timing??) in an S-10 truck.
> In the past few weeks I've been worrying less about preserving battery 
> life and playing with the capabilities of the drive a little more to get 
> an idea of what the next truck (!) needs to really drive like a "normal" 
> ICE truck.
> 
> With nice full batteries, I went for a run up the local Big Hill. In the 
> back of my mind I was aware that this might result in a blown fuse, 
> melted battery terminal, etc (The battery dealer stuck me with batteries 
> that have "L" terminals cast on top of the original terminals). But 
> relatively nice day and 15 minute walk back. So why not.
> 
> I went up fine, topping out at 55 mph. Just after cresting, when I let 
> up on the go pedal I heard a small "zap" (uh-oh) and the control went 
> into red-light mode. Coasted on off and parked. Meter confirmed what 
> ears and nose told me: the fuses, wires, etc were all fine and the 
> controller itself had blown. Either the super fast semiconductor type 
> fuse didn't do its job, or more likely the motor loop current got too 
> high? But why *after* I let up on the go pedal?
> 
> I did log the data from the run. The Big Hill was pulling 400-500 amps, 
> with some excursions to about 600 amps over a 1.75 minute period. This 
> was at around 110-115 volts, so works out to 50-60 KW (61 KW peak).
> 
> On removal, found a small scorch mark inside the controller and a loose 
> screw blown off a transistor. Odd part is on the outside of the case is 
> what looks almost like an arc hit the edge. But this doesn't line up 
> with anything under the hood, and in fact the flange is held captive 
> inside another flange so I'm not sure what caused it. I may remove the 
> mounting plate and look harder.
> 
> For repairs, I talked to AllTrax/DCP. As production has ended and all 
> units made are out of warranty by now, they are not providing real 
> repair support anymore. Since it visually appears that the damage is 
> limited, they are willing to take a look at it and see if the bad 
> transistors can be bypassed and then the unit "de-tuned" for a lower 
> power rating (with my vow to drive gentle). But they are not up for 
> taking it all apart and replacing the bad parts. :-(
> 
> At least it answers the question of whether to recycle the controller in 
> the next truck.
> 
> 
> _________
> Jim Coate
> 1970's Elec-Trak
> 1992 Chevy S-10 BEV
> 1997 Chevy S-10 NGV
> http://www.eeevee.com
>