FSAE 2014 rule book, EV 5.1.6 rule clarification

[Sud600]

Hi,
I am Sudharshun Iyengar representing a formula Electric Car making Team called Team Ojas from India. I have a small confusion regarding a rule in the FSAE 2014 Rule Book.

Let me quote the rule that I am confused with “EV5.1.6 - All circuits that are part of the shutdown circuit have to be designed in a way, that in the de- energized/disconnected state they are open such that each circuit will remove the current controlling the AIRs.”

We have designed our circuits in a way that the shutdown circuit opens only when a fault is detected cutting the current controlling the AIR from the shutdown circuit. The relays, that makes and breaks the shutdown circuit, closes the shut down circuit when the power supply to individual circuits are turned off.

The question is, according to the rule, does the individual circuit need to open the shutdown circuit when the power supply to them is cut or have we implemented the above mentioned rule correctly?

Thank you

[tobias.rheinlaender]

Hi Sudarshun,

I might confuse some of your make, brake, close, open... circuit descriptions. So just let me ask you to look at all your (relevant) components and check what would happen if any of those loose power or any security relevant cable or connection comes off (including the connection between the device and a relay driver circuit, the relay, sensing cable, ...) If the answer always is 'The power to the AIRs is cut right away.' I believe you are fine - else a redesign is propably necessary (and sit down to think about what could go wrong and how would YOU design a fail save circuit. Also that pesky document called FMEA might actually get you into the right mindset.)

Hope this helps! Good luck!

Kind regards,
Tobias R
Combined University Racing Berlin (CURB) - Germany

[Sud600]

Thank you Tobias. Your reply is helpful and very much appreciated.

[Sud600]

Hey Tobias,
Another rule clarification. EV 3.4.3 "All accumulator containers must lie within the frame."
In our design, we use 2 battery packs on either sides of the car. The batteries are placed such that bottom 3/4th of the car is covered by chassis frame and the battery container is tightly bolted to it. The top 1/4th of the container pops out, that is covered by water proof panelling. Hence the entire battery container is covered and water proof. So have we satisfied the rule?
Awaiting your reply.