Comment by quickthrowman
7 months ago
> and breakers are slow enough you could see multiple joules of energy into your device.
The magnetic part of a miniature circuit breaker will trip in nanoseconds with enough fault current or over voltage, but the thermal elements can take longer to trip for a lower amount of fault current or voltage. Instantaneous trip ratings are generally max out at 16.67ms to clear the fault in one cycle.
Large frame circuit breakers have protection relays that detect fault current and over voltage and trip the breaker.
Breaker trip curves for Cutler Hammer BR breakers: https://www.eaton.com/content/dam/eaton/products/low-voltage...
I am not sure if you're agreeing with me or not. Assuming you are, thank you. Nanoseconds could save you but milliseconds will likely not. It takes very little to explode a chip that isn't fortified and designed for robustness.
Instantaneous trip will kick in with 3-5x over current which happens in nanoseconds. Thermal overloads take longer so they don’t nuisance trip on inrush motor current (not applicable to single-phase motors due to start/run capacitors) Also, what chip is taking in line voltage single-phase AC at 120V or 208V or 277V or 480V?
All of the semiconductors I am familiar with run on low voltage DC with an inverter between AC and DC.