Relay for Ceramic heater control

Discussion in 'The Projects Forum' started by HomeBrewJeff, Jan 3, 2010.

  1. HomeBrewJeff

    Thread Starter New Member

    Jan 3, 2010
    Question regarding the appropriate relay used to control a ceramic heat emitter (CHE) commonly used to heat enclosures for lizards, snakes, etc.

    The relay I'm looking at is rated at 3A @ 120VAC and the coil will be controlled using an Arduino/Sanguino.

    The CHE will be either a 100watt or 150watt variety:

    Any major concerns with this relay? I can go with a beefier SSR if I have to, but i have a few of the above laying around and would like to put them to use. :)

    If the above is OK, would there be able concerns with noise/EMF in this setup?
  2. SgtWookie


    Jul 17, 2007
    You could possibly use that relay, but I don't know about the surge current when power is first applied to the ceramic heater.

    Incandescent lamps have a very high initial surge current when they're turned on; perhaps seven to ten times their normal current. Once the filament heats up (very quickly) the current through it decreases to normal levels.

    If this heater doesn't emit light, it would probably work OK.
  3. Paulo540


    Nov 23, 2009
    Since you are making into the load, and then breaking when the current is lower, it should work. Although, if you want to ensure that you don't cook your reptile buddy, you might want a secondary overtemp kill switch wired in before the stat.
  4. HomeBrewJeff

    Thread Starter New Member

    Jan 3, 2010
    Thanks! Just to clarify, would I be better off using a larger mechanical relay (i.e. 10A), or going to an SSR? I'm also planning on powering some large muffin fans, so I could use these relays for the fans.