Kansas ecm motor rpm tev026

Discussion in 'Maintenance and Troubleshooting' started by charr, Apr 8, 2015.

  1. charr

    charr New Member

    Recently purchased a tev026 and the ecm motor ramps up to 1400 rpm which seems to be max on fairly low cfm settings. 500 will get you there. So it will be at 1400 in heat stage 1 2 or auxiliary. Motor is only rated for 300 to 1250 rpm. The high rpm is not needed. Air is coming out of vents like a fan. Half the rpm would do the trick and would be a lot less noisy and create more even air distribution. Static pressure readings are fine and there is plenty of return air. Ductwork is sized correct. If anything oversized. Merv 11 so that shouldnt restrict return too much. Been told it is a board communicating issue but wanted to know if anyone had any ideas?
     
  2. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    How do you know it is making 1400 RPM?
     
  3. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    Did tech try reducing cfm?
     
  4. charr

    charr New Member

    The thermostat says so. You can see a bunch of stats like ewt and leaving water temp and air temps on the thermostat. It consistently shows right around 1400 rpm at 600 750 or 850 cfm. In fact, to get it down to something lower, I need to drop cfm to lowest possible setting with ecm motor. 450 cfm. still at that setting there is plenty of air coming out of all the vents and rpm runs close to 1200. One thing I did do was increase the size of a couple return air vents and that lowered the rpm by 50 to 70 at these very low cfm settings. all higher ones still ramp back up to 1400 rpm. there is plenty or return air now. Also, the tech put in a damper off the main shoot to try and fix static pressure before more return air was added and anything other than completely open will raise the rpm readings on the fan settings. fan settings are 350 cfm and run around 900 rpm (still providing plenty of air) but if you close the damper some that will ramp back up to higher rpm.
     
  5. charr

    charr New Member

    I did and have put stage 1 at 450 cfm and that has lowered the rpm to around 1200 or so. I can't go any lower with an ecm motor. I wish I could go down to fan speeds of 350 cfm because that would still provide plenty of air and would be quieter and have more even air distribution. In the installer settings, there are 4 or 5 motor settings but I think for an ecm motor I need to choose the ecm motor setting. Perhaps I can choose an older psc setting and that will allow me to do different things but I don't know the answer to that. with the fan ramping like it is the rooms which are over 1000 feet (9 6 inch ducts for the 1000 feet that is two floors and several different room) can be heated and cooled just fine with a cfm setting down in the 300's but I know that isn't how it should work because the system won't even let me go that low. Whatever gets the motor to respond is making the motor overreact and think it needs to push way more air than it actually needs to. Please see previous post about some of the ductwork things that have been tried to see what effect that can have.
     

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