Finding relay for high current

Discussion in 'Test & Measurement Forum' started by Michael Grenader, May 20, 2019.

  1. Michael Grenader

    Thread Starter New Member

    Dec 27, 2015
    8
    0
    Hey, im trying to build an automatic setup to test smart switch. I have a few points to connect to the load and i want to put a relay between each test point and the load. I want to load at 50 amps, and the maximum voltage for the card supply is 30 volt. Can someone recommend me a relay that will work on those requirements? I searched a lot on thr web and couldn't find anything that is suitable, most of the rrlays i found was for 50 amps but only 12-24v dc.
    Thanks in advance
     
  2. Janis59

    Active Member

    Aug 21, 2017
    702
    109
    If the unit is made for short tests not a working years and years, then for switching-on some small overstepping the voltage is OK. It just will shorten the life span of relay but no other big problems. But be careful to DIS-connect that load if relay voltage is loo low, that will immediately end with plasma and fire. By the way, Im curious, about WHICH voltage You are speaking, the contact max voltage or coil work voltage?
     
  3. Janis59

    Active Member

    Aug 21, 2017
    702
    109
    P.S. The railways are using some giant relays for 600V 1200A, sometimes they dismount them thus may find trashed along the rails.
     
  4. Michael Grenader

    Thread Starter New Member

    Dec 27, 2015
    8
    0
    Hey, thanks for the reply, the setup supposed to work for switching for a couple of minutes and switching back off again. The voltage is the supply voltage from my power supply, im supplying max 30 volt, and loading for 50 amps
     
  5. Michael Grenader

    Thread Starter New Member

    Dec 27, 2015
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    Its too much for me, i dont think i will walk along the rails searching for relays hhh
     
  6. Yaakov

    Well-Known Member

    Jan 27, 2019
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  7. joeqsmith

    Member

    Oct 15, 2016
    63
    11
    Looks like around 30W. The SSR's current/temperature derate curves may be a problem. MOSFET seems like a good choice but maybe just pick a better part with a lower RSDon.
     
  8. rsjsouza

    Active Member

    Apr 21, 2014
    165
    61
  9. MaxHeadRoom

    Expert

    Jul 18, 2013
    18,249
    5,605
    @Michael Grenader You could also look at a Automotive starter solenoid, you can get the simple stand alone version, mybe an auto-wrecker would have them.
    Amazon have them also:
    WARN 72631 Solenoid Replacement
    Max.

    You mean like this!:eek:
     
  10. Michael Grenader

    Thread Starter New Member

    Dec 27, 2015
    8
    0
  11. Michael Grenader

    Thread Starter New Member

    Dec 27, 2015
    8
    0
  12. rsjsouza

    Active Member

    Apr 21, 2014
    165
    61
    What exactly do you mean Vdc? Is it the coil or the maximum contact voltages?
     
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