Crimson Racing Wiki

Safety Shutdown Latching

Subteam: EV Power SystemsSubsystem: Accumulator LVAssembly: Interlock CircuitCars: CR26E

Purpose

Hold the shutdown state once a fault has occurred, so a momentary fault does not clear itself.

Function

Latching circuitry in the accumulator low voltage system that keeps the accumulator isolation relays open until the fault is cleared and the system is deliberately reset.

Design Process

No part-specific design process is documented. The Accumulator LV subsystem design process applies: 1. List every low voltage function inside the container and what it must interface with. 2. Decide grounding architecture (star chosen) and lay out the returns. 3. Design the boards, with conformal coating selected against the requirement (acrylic is easier to rework, silicone is more vibration resistant and more temperature tolerant but costs more and is harder to remove). 4. Design HV monitoring: optocoupler (smaller, cheaper, digital, needs conformal coating) against voltage transducer (no conformal coating needed, larger, more expensive, analog). 5. Build the sub-harnesses, test in simulated conditions before the pack is live.

Reoccuring issues

None recorded. This part has no entry in Knowledge_Transfer/Issue Logging/Fault Vault.xlsx, in either Issue Log.xlsx, in CR22/Issue Tracking/Shakedown 7-15-23.xlsx, or in any design review issue list found in CrimsonStorage or Box.

Still to document

Nothing in CrimsonStorage covers these yet.