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Selection of relay for driving a immersion rod

  1. Dec 17, 2012 #1
    i am designing a heating element control system. i am looking for a relay(with 5V input voltage if possible or 12V) which can control an immersion rod with specification 16-A & 250 V AC. The following are my questions.

    1. the heater has to be driven with power sockets(type M sockets -16A). can i use normal sockets of "type D"(which produces max current of 15A). what will happen if i use this. will the heating process be slow because of lower current driving capacity of the socket or the effect will create some problems ?

    2. to control this heating element i am using MSP 430G2231. is there any switching device instead of relays like mosfets which work out cheaper for controlling the heater with specified ratings.

    3. which relay might suit my requirements. cheap and best ones.

    4. i am using LM35 as my temperature sensor. please suggest me with some other best,cheap and user friendly sensors with resolution upto 0.5 degree.

    thank you all.
  2. jcsd
  3. Dec 17, 2012 #2


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    hi there

    do a google search on SSR (Solid State Relays) and mains contactor relays
    they are available with low voltage/current drive and being able to switch high voltages and currents

    Last edited: Dec 17, 2012
  4. Dec 17, 2012 #3

    jim hardy

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    What Dave said.

    For that current and voltage you'd almost need a motor starter with heavy silver contacts, and the sparking would generate EMI. SSR will be much easier to use.

    Pick one that closes on the zero crossing.

    EDIT: RE socket rting - never overload one by design. Good design would use it at around 70% of its rating.
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