[DeTomaso] front condensor question

[Tomas Gunnarsson]

There is no direct connection between the engine needing cooling and the
condenser fan running so I suggest separating the activating circuits.
At highway speeds the AC may well be needed but neither radiator nor
condenser need aid from fans to operate properly. Factory systems turn
the condenser fan on by system pressure. If the car is moving the
pressure stays down and the fan off. This is not the same switch as the
over pressure switch that turns the compressor off. I thought one of the
main benefits of moving the condenser up front was that it ends up in
the cool airflow from the grille. Why would you want to have the fan
running continously then?
 
Tomas

<-----Ursprungligt Meddelande----->

 	  	 From: Boyd Casey [boyd411 at gmail.com]
Sent: 6/8/2014 2:18:13 AM
To: scott at saccrestorations.net
Cc: detomaso at poca.com
Subject: Re: [DeTomaso] front condensor question 

My point was that with the radiator fans running when I would turn on
the 
ac switch the compressor would go on ( the fans would already be
running. 
If it's hot enough for AC I would assume that both radiator fans would
be 
on. Of my two radiator fans one is controlled by an thermostat switch
and 
the other by a lower thermostat switch ( upper and lower on the
radiator) I 
guess I could install an over ride switch that would insure that the fan
behind the condenser would turn on when the ac was turned on regardless
of 
the thermostat switches. 


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 
> 
> 
> _______________________________________________ 
> 
> Detomaso Forum Managed by POCA 
> 
> DeTomaso mailing list 
> DeTomaso at poca.com 
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> 
	
-------------- next part --------------
   There is no direct connection between the engine needing cooling and
   the condenser fan running so I suggest separating the activating
   circuits. At highway speeds the AC may well be needed but neither
   radiator nor condenser need aid from fans to operate properly. Factory
   systems turn the condenser fan on by system pressure. If the car is
   moving the pressure stays down and the fan off. This is not the same
   switch as the over pressure switch that turns the compressor off. I
   thought one of the main benefits of moving the condenser up front was
   that it ends up in the cool airflow from the grille. Why would you want
   to have the fan running continously then?



   Tomas
   <-----Ursprungligt Meddelande----->

       From: Boyd Casey [boyd411 at gmail.com]
   Sent: 6/8/2014 2:18:13 AM
   To: scott at saccrestorations.net
   Cc: detomaso at poca.com
   Subject: Re: [DeTomaso] front condensor question
   My point was that with the radiator fans running when I would turn on
   the
   ac switch the compressor would go on ( the fans would already be
   running.
   If it's hot enough for AC I would assume that both radiator fans would
   be
   on. Of my two radiator fans one is controlled by an thermostat switch
   and
   the other by a lower thermostat switch ( upper and lower on the
   radiator) I
   guess I could install an over ride switch that would insure that the
   fan
   behind the condenser would turn on when the ac was turned on regardless
   of
   the thermostat switches.
   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
   >
   >
   > _______________________________________________
   >
   > Detomaso Forum Managed by POCA
   >
   > DeTomaso mailing list
   > DeTomaso at poca.com
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