Re: Curtis controller model numbers

[Rod Hower <rodhower@ameritech.net>]

Hey Rich, if you do have a schematic, send it my way.
I can look at Orcad and powerlogic (ie. power-illogic).
File size is not a concern.

Thanks,
Rod

Otmar wrote:

> James Massey wrote:
> 
>> Hi all
>>
>> We have in for repair a couple of Curtis 1209B-7204 controllers, rated as
>> 72-120V, 275A.
>>
>> Q1) Do Curtis rate controllers on motor amps, battery amps, or both 
>> the same?
> 
> 
> Motor amps, which never exceeds battery amps.
> 
>> Q2) Does anyone have data on what this controller is supposed to do?
> 
> 
> PWM the output to control a series motor. The rest is safety and 
> protection.
> 
>> the
>> customer has an OEM connection drawing, showing the 4 power terminals, a
>> 2-wire pot and a control wire on the 3rd terminal - but it fails to show
>> where the other end of this control goes to! we suspect it is switched B+
>> w.r.t. B-, but can someone help?
> 
> 
> Control wire is called KSI and it goes to B+ to turn the controller on.
> 
>> Q3) Those of you who have had Curtis failiures, what failed and do you 
>> know
>> why?
> 
> 
> #1) Water in the unit
> #2) freewheel diodes overheat, short and blow the fets. The current 
> limit has no control below 10% duty cycle on the "B" models and 
> therefore can not maintain safe currents with a low resistance motor and 
> high voltage pack at stall. This makes the diodes overheat.
> 
>> As an aid to repair we are drawing up the circuit.
> 
> 
> I did that 10 years ago on a 1221B. (wow! has it been that long!) Later 
> Rich Rudman cleaned and corrected what I scribbled. I believe the 
> control board of the 1209 is very similar if not identical to the 1221.
> 
> Rich, have you got an electronic copy handy? A gif would be great, but 
> if you have the OrCad file I think I could get someone to distill it 
> into pdf.
> 
> -Otmar-
> http://www.evcl.com/914  My electric 914
> 
> http://www.CafeElectric.com
> Mailto:otlists@evcl.com
> 
>