AC relay - run on DC?

Discussion in 'General Electronics Chat' started by Man_in_UK, May 24, 2013.

  1. Man_in_UK

    Thread Starter Active Member

    May 13, 2008
    I have an Omron MKS3PI-5 relay with an AC24V coil.

    Will there be any bad effects on running it on 24VDC?

    I realise I could just purchase a DC version but there is a valid reason to use the AC type.

    Any help will be great
  2. gerty

    AAC Fanatic!

    Aug 30, 2007
    I have used ac 24volt coil relays on 12volt dc before. I used them for intermittant use and had no problem.
    The major difference, that I'm aware of, is ac relays usually have a shading ring around the laminations, and a dc relay doesn't.
  3. #12


    Nov 30, 2010
    We had this discussion maybe a year ago. There is a reason to use relays the way they were built to be used. You want to hobby a bit? Go ahead. Building a satellite for NASA? Follow the rules.
  4. Dodgydave

    Distinguished Member

    Jun 22, 2012
    The AC coils have a Shader ring around them to prevent chattering, if using it on DC, drop the supply by 25%.

    spark8217 likes this.
  5. crutschow


    Mar 14, 2008
    As Dodgydave said you need to reduce the voltage if you operate an AC coil on DC because of the lower impedance of the coil to DC versus AC. This is due to coil inductance. If you don't lower the voltage, the coil may burn out.
    spark8217 likes this.
  6. Man_in_UK

    Thread Starter Active Member

    May 13, 2008
    Cheers to everyone for giving me the answer.

    I was going to give a detailed explanation as to why I asked such a question but I don't have time. Satellite's don't build themselves you know.

    All I have to do now is try to work out what to do with this uranium!!!!!