Over voltage detection for shunt trip

Discussion in 'General Electronics Chat' started by Reneejoygould, Sep 5, 2008.

  1. Reneejoygould

    Thread Starter New Member

    Sep 5, 2008
    I need to protect my circuit from over voltage (520V) I already have a MCB for current and would like to use a shunt trip.
    Can anyone help me find a circuit that I can set the voltage to be detected and that will give an output of 24 V or appropriate to activate the shunt?
    Any help would be fantastic and greatly appreciated.
  2. Reneejoygould

    Thread Starter New Member

    Sep 5, 2008
    I forgot to mention my circuit breaker is three phase and my voltage to measure is DC after a bridge rectifier. I blew up a capacitor today 400 V 3300uF used to smooth the DC. Does anyone know what sort of voltage this cap can see before failing?
  3. thingmaker3

    Retired Moderator

    May 16, 2005
    Depends on operating temperature, age of the cap, and the ripple current.
  4. SgtWookie


    Jul 17, 2007
    It's best to use caps rated for twice the maximum voltage that they'll be exposed to.

    MOVs can help a great deal, along with transient supression diodes, to protect against "spikes" due to natural phenomenon. However, the protection provided is limited.

    It would help a great deal if you would post a schematic of your circuit.