[MikeJ]

Hello,


I'm hoping someone can help me with an issue I'm having with the NetGain Classic Controller. Here's the situation:


I recently finished converting my car and am in the process of testing out all of the systems. I've wired the controller using NetGains "redundant contactor" schematic which incorporates a contactor between the negative terminal of the battery and the B- on the controller. This contactor is turned on and off using the key switch as suggested in the NetGain manual. The problem (I believe) is that when I turn off the controller with the key switch the high voltage input to the controller is disconnected due to the contactor and the controller registers a "pack went oped circuit with system on" error code before shutting down.

Of course the error code keeps the controller from powering up again until it is manually reset (not good). If I leave the contactor always on the problem goes away but this defeats the purpose of the contactor (which is to keep the high voltage from the front of the car while turned off). If I shut the controller down first with a separate switch the problem goes away but this complicates the switching on/off sequence which I would rather avoid.


I've tried adding a simple RC circuit to the input of the contactor but since the contactor needs to be turned on before the controller and turned off after the controller I haven't been successful with this.


Has anyone else run into this problem or have an idea of how solve it?


Thanks,
Mike

 

[GerhardRP]

If you are using a standard automotive key switch, use the accessory position forcthe contactor and run for the controller.

 

[MikeJ]

The accessories output shuts off at the same time as the ignition output on the ignition switch so I don't think this will solve my problem. I need to delay the contactor by several seconds.

 

[Ziggythewiz]

What is your emergency off mechanism? There are several ways you could delay turning off the contactor, but unless you use a separate method for e-stop it could introduce a potential hazard.

Do you know that you need several seconds? How long does it take the controller to shut down?

 

[MikeJ]

I have a circuit breaker which can be "thrown" from inside the car as an emergency shut off so adding a delay to the contactor shouldn't be a problem. I'm not sure how long the delay really needs to be, maybe only a few 100ms will work. Actually the delay shouldn't be to long because the high voltage needs to be present when the controller first powers up. A small delay should be fine because the controller doesn't power up until the BMS checks the batteries and switched a relay. That should give the contactor plenty of time to switch the high voltage before the controller powers up.

Thanks,
Mike