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RMS solution for humidity 'control'

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  • RMS solution for humidity 'control'

    A simple but nice example of a basic control project that RMS was able to help a customer with. RMS is not a control system but this basic solution was suitable.

    Customer Requirement
    - Control a dehumidifier in a test area to ensure humidity remains below critical level. They could have used a HS5 / PF4 etc but they wanted to see the process in action if possible and didn't want to have a second probe in use if it could be avoided (already they had an RMS logger monitoring the room).

    - RMS digital output module (RMS-DO-L-R) used and configured to trip dehum unit on when high %rh met.
    - Monitoring probe configured with the room limits.
    - Second measurement point made as a 'duplicate' of the live values (achieved using sum calc with only one input). Using this measurement point we could set a lower alarm limit to ensure dehum trigger before the %rh got too high.
    - Tweaks to alarm levels and hysteresis band ensured smooth control (+/- <2 %rh)

    Image showing
    - Live %rh from monitoring probe (alarm limit @ 35 %rh) No alarms triggered during test!
    - Duplicate of above reading (alarm limit @ ~32 %rh) Multiple alarms triggering relay
    - Relay output (dehum unit on)
    - Live temp from monitoring probe (not controlled by RMS)

    Click image for larger version

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  • #2
    Hi Jeremy

    Very smart "concept" to just add a duplicate of a measuring point, with the sum calculator

    The only requirements to the dehum is for it to have relay output that you put in the RMS-DO-L-R and is what makes RMS able to switch the relays on the dehumidifier. correct? :-)

    Best Regards
    Emil Larsen
    RMS-manager @ C.K. Environment A/S
    Dir. : +45 3144 2656 • Main: +45 4498 9906
    el@cke.dkWWW.CKE.DKRotronic Monitoring


    • #3
      We the dehum unit needs a switch inputr... this is tripped by the RMS-DO unit (i think that is what you mean anyway!)... I was pleased when i realised you could use sum calc with a single MPT otherwise the customer room alarms would have to match the dehum on off triggers or I would have to use complicated scripts.