Re: Air Conditioner Freezing Up


George E. Cawthon wrote:
> RP wrote:
> >
> >
> > George E. Cawthon wrote:
> >
> >> CBHVAC wrote:
> >>
> >>> "Michael." <michael.knost@xxxxxxxxx> wrote in message
> >>> news:1135098728.120592.304690@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> >>>
> >>>> The fan motor on my outside unit died last week. I took the fan motor
> >>>> to a local appliance parts store and they gave me a new one. The new
> >>>> one had a longer shaft but they said that did not matter. I replaced
> >>>> the fan motor and it seems to work fine. The air is blowing up out of
> >>>> the unit. However, when I run the air now the interior unit freezes
> >>>> up.
> >>>>
> >>>> Any suggestions would be appreciated!!
> >>>
> >>>
> >>>
> >>>
> >>> 1- Did you replace the motor with the EXACT same HP and RPM? If you
> >>> did not, you have a problem.
> >>> 2-did you put the fan back EXACTLY where it was located in relation
> >>> to height? if not, you have a problem.
> >>>
> >>> If you have too much airflow over the condensor now, you have changed
> >>> the operational characteristics of the unit, and while you can
> >>> correct it with the proper tools and knowhow, I would suggest that
> >>> either you had an issue in addition to the fan motor, or, you have
> >>> put a fan motor on that is too high of an RPM now, and thus, created
> >>> a charge issue with the unit.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>
> >> Are you talking about a home unit? If so, I don't believe it. My
> >> condenser unit couldn't blow any harder. If it doesn't blow enough,
> >> that is obviously a problem. Besides the OP indicated the motor only
> >> differs by having a longer shaft.
> >>
> >> Blowing too much, if possible, would have less effect than the normal
> >> changes in outside temperature. How in the hell could any hp change
> >> or motor speed adversely affect the condenser as long as it is keeping
> >> the coils cooled? Unless, of course, some one has some cobbled up
> >> design that involves electronic control of the blower motor that is
> >> supposed to save energy.
> >
> >
> > Excessive condenser airflow will simulate a lower ambient. If ambient is
> > in the mid to low 70's as the OP states, then with a larger and thus
> > slightly faster motor the unit will *percieve* an ambient in the mid to
> > upper 60's, in which case a piston evap coil can easily freeze up,
> > especially if it was a bit undercharged to begin with. The new motor can
> > very well be the difference between evap freezing vs not freezing. This
> > can also occur even if the motor specs are identical. How? Well let's
> > get this out of the way too. If the old motor wasn't running up to speed
> > and the refrigerant charge was adjusted under those conditions, then it
> > will have actually been left undercharged. The result is the same as
> > installing a higher HP motor.
> >
> > In this case the OP said that he also cleaned the condenser coil. This
> > could very be the only thing that caused the evap to start freezing up.
> >
> > hvacrmedic
> >
> I'm astounded. If what you say is true, then some
> engineer should come forward with a new design or
> at least a new control system that would put all
> the others out of business. Further, homeowners
> would be constantly experience problems for which
> there was no remedy because they would be due to
> environmental changes. And the units on autos
> would be virtually useless.
>
> I think you are reaching. If the charge is wrong
> it is wrong. Sure it may not show up under some
> conditions and new changes could make it show up,
> but the problem is the charge.
>
> My home unit works in all kinds of weather and all
> reasonable temperature and humidities and I have
> never experienced any kind of freezing up (of
> course I don't run it when the temperature is 20
> degrees, in fact, it never run when the ambient
> temperature is below 75 degrees.)
>
> My automobile units work in more drastic
> conditions since my truck AC works in any
> temperature at some setting and it never fails to
> cool.

This is Turtle.

George , Richard put the correct words in his writting as the system
could be slightly under charged in most all his cases which left the
door open to cause of low on freon to freeze it up. Richard covered his
ass with correct writting but the one you should be talking to is
CBHVAC for he is the one that put his foot in his mouth here by fully
stating the a fast running condenser fan motor will freeze up a
evaperator coil, period.

TURTLE

.

Relevant Pages

  • Re: Air Conditioner Freezing Up
    ... I replaced the fan motor and it seems to work fine. ... Blowing too much, if possible, would have less effect than the normal changes in outside temperature. ... How in the hell could any hp change or motor speed adversely affect the condenser as long as it is keeping the coils cooled? ... The new motor can very well be the difference between evap freezing vs not freezing. ...
    (alt.home.repair)
  • Re: Air Conditioner Freezing Up
    ... I replaced the fan motor and it seems to work fine. ... a charge issue with the unit. ... condenser unit couldn't blow any harder. ... reasonable temperature and humidities and I have ...
    (alt.home.repair)
  • Re: Air Conditioner Freezing Up
    ... I replaced the fan motor and it seems to work fine. ... Blowing too much, if possible, would have less effect than the normal changes in outside temperature. ... How in the hell could any hp change or motor speed adversely affect the condenser as long as it is keeping the coils cooled? ... The new motor can very well be the difference between evap freezing vs not freezing. ...
    (alt.home.repair)
  • Re: Air Conditioner Freezing Up
    ... They don't have no fan laws that would speak about too much air across ... the coil as small as going from a 825 rpm motor to a 1075 rpm motor. ... over to 1075 and just change the blade or increase the h.P. ... blade for each unit as to 2 and 5 ton condenser blades. ...
    (alt.home.repair)
  • Re: Air Conditioner Freezing Up
    ... I replaced the fan motor and it seems to work fine. ... too much air across a condenser coil will freeze up the evaperator coil ...
    (alt.home.repair)