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Cool little tool for verifying circ pump rotation ?

Dave Carpentier
Dave Carpentier Member Posts: 620
in THE MAIN WALL
Watched a tech whip out a small keyfob looking tool and held it against the end of a circ pump. The little bar on the tool spun around (like a compass needle spinning), so he knew the pump was currently operating.
Such a simple and useful thing.
Everyone has one of these I guess ?

30+ yrs in telecom outside plant.
Currently in building maintenance.

Comments

  • hilltown
    hilltown Member Posts: 30
    Grundfos MRI Run Indicator Magnetic Rotation Instrument Key

  • hot_rod
    hot_rod Member Posts: 23,392
    But don’t be fooled, it may be spinning and the pump is not. It reads the electromagnetic force being present. It does not work on all brands of pumps, or on ECM type.
    It will also spin when pressed against some solenoid valves. That are not rotating.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    GroundUp
  • Dave Carpentier
    Dave Carpentier Member Posts: 620
    Just like that. Not sure if it was Grundfos.
    If I can find my compass around here somewhere, I'm gonna see if that works.
    30+ yrs in telecom outside plant.
    Currently in building maintenance.
  • hot_rod
    hot_rod Member Posts: 23,392
    Many different companies used them for giveaways. Get one at Amazon, and here is the manufacturer
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,214
    The Danfoss magnetic tool app. is probably just as reliable. 

    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
    Zmanheathead
  • hot_rod
    hot_rod Member Posts: 23,392
    But still not a proof of rotation
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    Alan (California Radiant) Forbes
  • pecmsg
    pecmsg Member Posts: 5,291
    I've seen as many False readings as positive. It shows Voltage present not that its turning!
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
    You can get the same basic info from just clamping your meter onto it.

    There was an error rendering this rich post.

    pecmsg
  • hot_rod
    hot_rod Member Posts: 23,392
    STEVEusaPA said:

    You can get the same basic info from just clamping your meter onto it.

    or a voltmeter
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream

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