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AnnexAir wire sizing

Discussion in 'Commercial' started by LemonWizard, Sep 8, 2017.

  1. LemonWizard

    LemonWizard Blinky Lights Wizard

    Messages:
    2,145
    Location:
    Ohighyo
    Does this seem odd to anyone else or am I just not used to Canadian engineering?

    The unit I'm redoing the controls on has this for a condensing unit, it's powered by a 15A breaker in the unit so this is factory designed. Compressors are 3phase.

    Power leads into the condensing unit are 12 awg aluminium.

    Unit has had 'phase loss monitor' issues from the day it was installed. I'm wondering if it isn't just picking up a voltage drop maybe when both compressors start at the same time.

    Unit is in the middle of being recontrolled so I can't test anything for a few days.

    20170908_131249.jpg
     
  2. pecmsg

    pecmsg Junior my ASS

    Messages:
    21,192
    Location:
    Eastern LI
    With both Comp trying to start at the same time I'll bet you show low voltage.

    Time for a time delay
     
    LemonWizard and jettinvr6sc like this.
  3. LemonWizard

    LemonWizard Blinky Lights Wizard

    Messages:
    2,145
    Location:
    Ohighyo
    And not really a wiring question but is it normal for annex air to design their units with blowers at 80+Hz?

    I swear every single one in this building is like this and the smaller the motor the louder it is.

    :headscratch:
     

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  4. flange

    flange Act like you care and do SOMETHING!!

    Messages:
    12,871
    Location:
    IMT--in my truck
    we have seen units running as high as 97 hertz on the blower motors. those wheels can be more efficient when running at higher rpms. one thing you need to be careful of is that you are not surging. you will see vibration and or noise if it is. when they surge it doesn't show up like on a centrifugal chiller as a very distinct noise.
     
    LemonWizard and crackertech like this.
  5. crackertech

    crackertech assholiness *

    Messages:
    91,500
    Location:
    Fl/IN/Ga/Ms/TX/NJ/VA/NC/TN

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