Quote:
Originally Posted by jkredman
Gentlemen:
One other question before I assume I toasted my new controller....
The cart jerks violently when the key switch is turned. I've read in other threads, there is a twist test that's performed and perhaps the brake is failing the twist test. Is that a possibility?
The new controller is the 350 amp Curtis and I think the old Danaher was something like 250, or 235 AMPS?
Is it possible that the new controller has uncovered an impending issue with the brake?
After all this cart started life as a 2010 fleet cart....
Thank You
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Yes, it is failing the twist test. The motor brake is being held in an on condition when it should be off. The likely cause would be the motor brake FET being shorted. It is possible that there was an existing problem with the motor brake, but connecting the wrong wire is just as likely a cause. Checking the resistance of the motor brake coil is the way to test it. The target resistance at DC is 25.5 ohms. In operation, the FET is driven by a PWM at a pulse rate which gives the controller a different value. But DC resistance can be used to test it with an ohm meter on the 200 ohm scale.
My motor brake FET failure was caused by a brand new motor brake that turned out to be defective. I know these Curtis controllers well, so I decided to repair it myself. I prefer the programming aspects more than doing hardware repairs, but I do have the knowledge and equipment. I've designed controllers for a few decades, and I still do that for equipment that I have patents on.
FSIP can repair the common Curtis RXV controllers, such as the 1206AC-5201 to 1206AC-5211. I know that they did not have the 1206AC-53XX 350 Amp upgrade controller files (OS and VCL) or the 1206AC-5212 2Five controller files the last time I had talked to them. I sent them files for the 2016 era 1206AC-5211 controller back in 2017 when Curtis would not supply them with the files because they were still within the factory warranty period.
Curtis does not let FSIP repair controllers that are within the factory warranty period. The way FSIP usually works is you buy a controller from them, then send your controller to them, and they give you a $25 core in return. Not worth it in my opinion. Your damaged controller is worth more than $25. They won't have a 1206AC-5350 on hand anyways, as they are pretty uncommon. They will have plenty of 1206AC-5201 and newer stock 235 Amp controllers, but that would be a downgrade for you.
I wish you were closer. I bought a new 1206AC-5350 to use for my RXV chassis based road car project that I intend to finish once the weather improves. I also have motor brake FETs. They are a royal pain in the *** to change out. They are surface mounted and heat-sinked to the PC board under them, so you must literally destroy the FET to get at the heat-sink tab to unsolder it. Typical hot gas reflow techniques do not penetrate the FET well enough to heat the tab to get it loose from the PCB. The PCB heat-sink pad works too well.
Bob