[DeTomaso] front condensor question

Brian Dudley bd8134 at gmail.com
Tue Aug 5 20:15:31 EDT 2014


If you use a trinary switch and it is wired correctly, at low and high
pressure it cuts off the ac compressor, it also has a preset pressure
connection which is wired to the cooling fans. The advantage of using a
trinary is the fan will only run when the condenser pressure is at a preset
level, ie enough cooling is provided from driving, Another function of the
trinary, is if enough cooling is not provided by the fans, like sitting in
traffic on a hot day, the compressor clutch is disengaged but the fans
still continue to run.



On Tue, Aug 5, 2014 at 6:54 PM, Scott Bell <scott at saccrestorations.net>
wrote:

> You need the fans running with the AC on because when the car is stopped,
> the pressure in the AC system will continue to build
> because there is no cooling happening without the fans running. This will
> cause the system to go into an overpressure situation
> causing the trinary switch to shut off the compressor or a hose to blow if
> there isn't a safety pressure switch installed in the
> system.
>
> -----Original Message-----
> From: DeTomaso [mailto:detomaso-bounces at poca.com] On Behalf Of Mike Drew
> via DeTomaso
> Sent: Tuesday, August 05, 2014 3:29 PM
> To: boyd411 at gmail.com; jderyke at aol.com
> Cc: detomaso at poca.com
> Subject: Re: [DeTomaso] front condensor question
>
>
> In a message dated 8/5/14 12 01 28, boyd411 at gmail.com writes:
>
>
> > If both radiator fans run and AC switch is limited to controlling the
> > compressor won't that work? Sometimes my car needs both sucker fans to
> >
> > maintain correct engine operating temp. If the one fan is controlled by
> > the
> > compressor switch wouldn't that limit sufficent radiator cooling to times
> > when AC was also turned on?
> >
>
> >>>You would definitely want the fans to be triggered by the radiator
> thermoswitches OR by the A/C.   Most conventional cars with front-mounted
> A/C
> turn on the radiator fans the moment the A/C system is engaged regardless
> of
> engine temp.
>
> Without anything scientific to back up this suggestion, I would think it
> would be advantageous to have the A/C system turn both fans on at the same
> time; however having the radiator turn the fans on sequentially saves wear
> and
> tear on the #2 fan, perhaps?
>
> Mike
>
>
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>
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>
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-------------- next part --------------
   If you use a trinary switch and it is wired correctly, at low and high
   pressure it cuts off the ac compressor, it also has a preset pressure
   connection which is wired to the cooling fans. The advantage of using a
   trinary is the fan will only run when the condenser pressure is at a
   preset level, ie enough cooling is provided from driving, Another
   function of the trinary, is if enough cooling is not provided by the
   fans, like sitting in traffic on a hot day, the compressor clutch is
   disengaged but the fans still continue to run.

   On Tue, Aug 5, 2014 at 6:54 PM, Scott Bell
   <[1]scott at saccrestorations.net> wrote:

     You need the fans running with the AC on because when the car is
     stopped, the pressure in the AC system will continue to build
     because there is no cooling happening without the fans running. This
     will cause the system to go into an overpressure situation
     causing the trinary switch to shut off the compressor or a hose to
     blow if there isn't a safety pressure switch installed in the
     system.
     -----Original Message-----
     From: DeTomaso [mailto:[2]detomaso-bounces at poca.com] On Behalf Of
     Mike Drew via DeTomaso
     Sent: Tuesday, August 05, 2014 3:29 PM
     To: [3]boyd411 at gmail.com; [4]jderyke at aol.com
     Cc: [5]detomaso at poca.com
     Subject: Re: [DeTomaso] front condensor question
     In a message dated 8/5/14 12 01 28, [6]boyd411 at gmail.com writes:
     > If both radiator fans run and AC switch is limited to controlling
     the
     > compressor won't that work? Sometimes my car needs both sucker
     fans to
     >
     > maintain correct engine operating temp. If the one fan is
     controlled by
     > the
     > compressor switch wouldn't that limit sufficent radiator cooling
     to times
     > when AC was also turned on?
     >
     >>>You would definitely want the fans to be triggered by the
     radiator
     thermoswitches OR by the A/C. A  Most conventional cars with
     front-mounted A/C
     turn on the radiator fans the moment the A/C system is engaged
     regardless of
     engine temp.
     Without anything scientific to back up this suggestion, I would
     think it
     would be advantageous to have the A/C system turn both fans on at
     the same
     time; however having the radiator turn the fans on sequentially
     saves wear and
     tear on the #2 fan, perhaps?
     Mike
     _______________________________________________
     Detomaso Forum Managed by POCA
     DeTomaso mailing list
     [7]DeTomaso at poca.com
     [8]http://poca.com/mailman/listinfo/detomaso_poca.com

References

   1. mailto:scott at saccrestorations.net
   2. mailto:detomaso-bounces at poca.com
   3. mailto:boyd411 at gmail.com
   4. mailto:jderyke at aol.com
   5. mailto:detomaso at poca.com
   6. mailto:boyd411 at gmail.com
   7. mailto:DeTomaso at poca.com
   8. http://poca.com/mailman/listinfo/detomaso_poca.com


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