Re: Help - dead EV-long

["David Roden" <roden@wksu.org>]

> GE EV 15 controller and a GE 20.9 HP motor ... it [controller] died ...
> 
> I have entered this vehicle in 1 event already - Clean Air Cruise -and 
> have been asked to supply the car next week for a TV drama about an EV 
> company. 
> 
> I'm anxious to get this car operating again.

If this is the lauded (and rarely seen) GE sep-ex (separately excited) 
regen controller and motor set, it is probably worth preserving.  That 
system, no longer available from GE, was reportedly pretty well designed, 
and also pretty expensive.

If this is a sep-ex motor, I'm afraid you are going to have a lot of 
trouble getting the car running in time to keep your commitments next 
week.  There is little chance of getting the parts for your controller by 
then.  Besides, there is a slight chance that you'd find after replacing 
the power supply module that its failure caused other damage in the 
controller.  

A real electronics ace might be able to make your controller work, even 
without a diagram.  But there are not many who would attempt it, and the 
ones who would usually can't work on such short notice.

Unfortunately , controllers for large EV sep-ex motors are relatively 
uncommon, and often need to be programmed for the specific motor.  So you 
are going to have trouble finding a replacement controller in a hurry, 
too.

Sometimes you can make a series-motor controller work with a sep-ex motor, 
but it usually requires some experimentation with powering the field, and 
often you need a high-current inductor in series with the armature to make 
the controller work right.  Such inductors aren't a stock item with most 
EV parts suppliers these days.

If it is a series motor, you have more options.  In that case you can 
probably use an inexpensive Curtis controller to get rolling again.  You 
would probably have to get a Curtis potbox too, because I believe the GE 
potbox differs.  You might even be able to get a local EV hobbyist to lend 
you such a controller while yours is being repaired.

You need to find out what kind of motor this is (series, shunt, compound, 
separately excited).  It may be indicated on the nameplate.  If not, check 
the motor connections.  If the field terminals and wires are markedly 
smaller than the armature terminals and wires, it is probably a sep-ex or 
shunt motor.  If there are four terminals for the field, it is probably 
a compound motor.  If the field terminals are about the same size and 
the armature termials, and you can tell from the wiring that the field is 
connected in series with the armature, it is a series motor.

As for repairing your GE controller, maybe some of our Canadian list 
members have some suggestions for service depots in Canada.

I hope this helps a little.

David Roden
Akron OH USA