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  • Users: rc10
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  1. rc10

    HVAC Fan Motor Cycling and Tripping

    Yep! Our company refused to pay for travel this year but I've been in the past and found them highly valuable. Update- our site HVAC engineer lost the battle and the only thing that the project team agreed to do was to remove the magnetic trip from the breaker because it was "redundant" to the...
  2. rc10

    HVAC Fan Motor Cycling and Tripping

    I would too, except for the cybersecurity requirements that come with installing a digital VFD in a nuclear power application. :( Ideally the outside firm, but somehow we always manage to get stuck with the bill for the mistakes of others. I've passed all of the advice in this thread to our...
  3. rc10

    HVAC Fan Motor Cycling and Tripping

    Thanks for the discussion on plugging duty- I couldn't find too many resources on this and have no experience with them. Our contactors are ABB AF09-30-10-13 which don't appear to be rated for IEC AC-4 utilization category. Could this explain why we've gotten trips despite not appearing to...
  4. rc10

    HVAC Fan Motor Cycling and Tripping

    @LittleInch, I appreciate the suggestions, it's great to have an independent review overlap with some of our ideas. Our engineers and independently the consultant has also batted around the idea of the timer and pressure switch adjustments. I initially suggested anti-rotation devices but am not...
  5. rc10

    HVAC Fan Motor Cycling and Tripping

    I have a multistage HVAC system that has four 3hp, 1800rpm condenser fans mounted in a common frame and duct with pressure switches set to energize them in sequence as refrigerant pressure increases. The system is less than a year old and we've had issues since installation with the fan motor...
  6. rc10

    MCSA - Motor Current Signature Analysis

    @JP.Duranti: attached is a combo of my personal reference for identifying these points of interest using our new online MCSA monitoring tool and a report I had made using our field tester. Although the tester software can automatically find these points of interest for me, I want to be able to...
  7. rc10

    MCSA - Motor Current Signature Analysis

    Attached for my sheethttps://files.engineering.com/getfile.aspx?folder=242f1bd6-b24f-4e38-bb86-c6b68922f162&file=MCSA_Cheatsheet.xlsx
  8. rc10

    MCSA - Motor Current Signature Analysis

    I have a spreadsheet to do this and superimpose the frequencies over our MCSA data. The points of interest I can look at are: Stator slot passing sidebands, stator line frequency sidebands, broken rotor bar and swirl effect sidebands, and eccentricity. You will need the following motor info...

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