1. Welcome to Hvacproforums, an interactive community exclusively for HVAC professionals. The collective years of HVAC experience and the knowledge our forum members share make this an invaluable resource for those in the HVAC industry. We have a lot of fun, but make no mistake, we are pros. Hvacproforums is self supporting ...there are NO advertisers here. Do-it-yourselfers and Homeowners are encouraged to seek information elsewhere. Those involved in the HVAC industry are urged to register. its 100% free and easy, Once registered you will have access to the technical forums, Be sure to click over to the new members forum and introduce yourself after registering!

Carrier I-Vu question

Discussion in 'Commercial' started by otto, Dec 7, 2017.

  1. otto

    otto Bakery Chef

    Messages:
    19,866
    Location:
    in a van down by the river
    I have a customer with a Carrier I-Vu BAS system. They gave me a user name & password that I can use on site, they are not yet set up for remote access. I will be there to do PM work on the rooftop units. They have VFD's in the units. I know I shouldn't just kill power to the RTU and want to disable it in I-Vu but just could not figure out how to do that.
    Can someone please help me here? I'm sure it must be easy but I just couldn't figure out how.
     
  2. frozensolid

    frozensolid Psychologist's Dream

    Messages:
    12,284
    Location:
    Earth
    Depends on the password otto. If they did not give you the highest level you will not be able to do that.
     
  3. refrigerationtech

    refrigerationtech Nut Case!

    Messages:
    2,022
    Location:
    Cold Place
    no inside service switch? I think you possibly could kill main power. just wait for the vfd to power down. don't turn off and back on. that should not cause vfd to detect surge or have issues.
     
    Chuck likes this.
  4. NZ All Blacks Fan

    NZ All Blacks Fan Just Another swinging Dick

    Messages:
    9,404
    Location:
    West Coast - Canada
    you may have to manually stop the vfd putting it into local control then stop - but on some carriers the vfd is in a shiatty location for access
    Ive always wondered what happens in a power outage with this setup you know
     
  5. doc havoc

    doc havoc A cunning linguist

    Messages:
    9,239
    Location:
    45.780245, -91.731582
    Forgive my ignorance, but what happens if you short cycle a VFD off/on?
     
  6. otto

    otto Bakery Chef

    Messages:
    19,866
    Location:
    in a van down by the river
    He said he gave me highest access
     
  7. pecmsg

    pecmsg Junior my ASS

    Messages:
    21,175
    Location:
    Eastern LI
    On a good drive that’s programmed properly, Nothing.
    The motor should ramp down to 0 and after a short delay start back up to its last command.
     
    doc havoc likes this.
  8. refrigerationtech

    refrigerationtech Nut Case!

    Messages:
    2,022
    Location:
    Cold Place
    Doc havoc hey there no ignorance. I saying not to turn it on and off due to inrush current may screw things up or set off/Tripp it off on alarm. Not good on Vfd or even anything matter fact


    Sent from my iPhone using Tapatalk
     
    doc havoc likes this.
  9. otto

    otto Bakery Chef

    Messages:
    19,866
    Location:
    in a van down by the river
    I have been told that a VFD should be turned off at the control or command/enable to allow it to turn itself off and not to interrupt main power.
     
  10. otto

    otto Bakery Chef

    Messages:
    19,866
    Location:
    in a van down by the river
    I don't think I have access to the parameters to shut equipment on & off. They did set up the remote access and gave me a password. I will find out more later. Maintenance is done for now so I won't be back for 3 months.
     
  11. pecmsg

    pecmsg Junior my ASS

    Messages:
    21,175
    Location:
    Eastern LI
    I’ll bet you forget the password!!
     
  12. HMD

    HMD does it matter?

    Messages:
    93,378
    Location:
    here
    upload_2017-12-7_17-38-42.jpeg
     
    A/C guy's girl and doc havoc like this.
  13. HMD

    HMD does it matter?

    Messages:
    93,378
    Location:
    here
    the 500hp schneiders i have go into a reset able alarm.
    need to wait for the caps to discharge before power on
     
  14. pecmsg

    pecmsg Junior my ASS

    Messages:
    21,175
    Location:
    Eastern LI
  15. HMD

    HMD does it matter?

    Messages:
    93,378
    Location:
    here
    :rolleyes:
     
  16. flange

    flange Act like you care and do SOMETHING!!

    Messages:
    12,871
    Location:
    IMT--in my truck
    if the drive thinks its off and the fan is freewheeling, it could see the motor acting like a generator and think voltage is present when it shouldn't be, and trip a fault code. depends on how the drive is set up.
     
    doc havoc likes this.
  17. heavyevans

    heavyevans FNG

    Messages:
    1,257
    Location:
    Indy
    I don't understand why anybody would tell you that.
     
    Last edited: Dec 7, 2017
  18. otto

    otto Bakery Chef

    Messages:
    19,866
    Location:
    in a van down by the river
    I hear that they now have disconnects at equipment like exhaust fans and the disconnect has an aux switch to open the demand/enable circuit for the vfd which is remote.
     
    HMD and crackertech like this.
  19. crackertech

    crackertech assholiness *

    Messages:
    91,463
    Location:
    Fl/IN/Ga/Ms/TX/NJ/VA/NC/TN

    I’ve seen that as well
     
  20. heavyevans

    heavyevans FNG

    Messages:
    1,257
    Location:
    Indy
    Yes, if the disconnect is between the VFD and the motor. It is standard practice to have an aux contact in the disconnect that disables the enable or safety circuit to the drive. Some drives don't care if the motor is connected and some do (they trip out on a fault).
    On the VFD's that don't trip out, they ramp up to full speed because the disconnect is open and the motor has stopped. VFD's are not designed to handle the inrush current that we see on a across-the-line-start which would happen when they are running at full speed and the disconnect is closed on a motor that has stopped.
    If the disconnect is before the VFD it is not a problem.
     
    Zman, doc havoc and otto like this.