The Queen customizes her 3.2

[GH85Carrera]

Originally Posted by echecsqueen

Shazam!!!!!!

Science wins again!

With a few bucks, a lot of blood sweat and tears, possibly some profanity, and lots of hard work, you are a cool customer on a hot day.

Congratulations. Ain't it grand when a plan comes together.

[echecsqueen]

Suitor- you really know how to make a girl smile. Beautiful game

[JRSIII]

Ok I’ll bite at the risk of ridicule…based on the bishop sacrifice note, I’m assuming white pawn takes black bishop and proceeds to lose?

Good job in the A/C!

[echecsqueen]

Yes jrs3
The sac of the black bishop is considered one of the all time best moves. It must be taken and yet it allows black to match the pawns down the board and win. Regardless of what white does, the move wins. Hard to see.
Thanks!!

[echecsqueen]

Thanks for all of your help!

[PeteKz]

It looks like my reply earlier today didn't post. I suggested that you move pawn to H5. See how that plays out.

[echecsqueen]

One question
When the ambient temp is 105 and the engine is fully hot (after long drive but now at idle) , the hi pressures go up above 300 and cause the high pressure switch to cut the compressor off. The refrigerant charts say that at 105 a pressure of 325 is fine but the switch cuts off before 325. So when the weather is the hottest and engine is hot, compressor starts rapid cycling. This seems to be an issue. Experts?

[tsuter]

The Hi cutoff pressure for R134a should be 406psi and 30psi for low (measured on the high side).

See this link for an example.

https://restomodair.com/shopproducts/trinary-pressure-switch/

[echecsqueen]

The Griffith cut off switch cuts the power at 325. When I take the switch out of the system, the compressor doesn’t rapid cycle. It tried one of his replacement switches- same issue. Cuts off at 325- which at 105 ambient (in the shade) and certainly much much hotter stopped at a traffic light or in slow traffic, is too low to be optimal. I spoke to him today and he said that is how the switch is spec’d so I think I need a switch that has higher tolerance for high pressure (and yes it is connected to the high pressure side). This is quite the education
On the switch itself (Griffith binary switch) it states “hi cut off 22.5 lb/cm3”

[tsuter]

So I don't know what compressor you have and that may be why the cutout is 325psi but that is no good and will not allow you to meet the necessary pressure to condense that R134 vapor back to liquid at high ambient temps.

For R134a you have to run high pressure. Higher than R12 to get "red zone" cooling.

Here are the specs you want for a binary(no fans) or trinary switch (fans better)
These are all measured on the Hi side as the switch is installed in the liquid #6 line (Hi Pressure) after the last condenser and before or at the drier.

Hi Safety Cut off 405PSI Saves the compressor cuts the clutch
Fan Cut On 240/250 +- PSI ie., the fans will come on and run until you hit 405. That should rarely happen
Fan Cut Off 180PSI The fans come on at 240/250 and then stay on as the pressures drop and off at 180. You want this 60-70PSI difference so that the fans do not cycle unnecessarily on and off.
Low Safety Cut off 30PSI Refrigerant leaked out... low cut off saves the compressor by cutting the clutch.

Pressure switches fail sometimes and for this reason they should be be able to be replaced without evacuating the system

Good video local San Antonio here: You don't need the temp control part though.
https://www.vintageair.com/tech-video-installing-a-trinary-switch/

[echecsqueen]

I have a stock type nippo denso compressor
I have Griffiths “in line “ binary switch that installs directly into his barrier hose at the high pressure side right after the compressor. This is where he placed it in his line kit.
The specs written on the switch he sent state that the high cut off is at 22.5 which is 304 psi. I agree that that is too low when it is this hot outside.
I just need to buy a binary switch that has a higher high cut off. Like you said 405. I don’t have a rear condenser fan- my rear condenser is mounted above my engine and only gets air cooling when in motion.
The switch is working at exactly the specs that are written on it. I believe that this switch he sent has a hi cut off that is about 100psi too low to work correctly at ambient 100degrees. Agree?

[echecsqueen]

Do I need to add a fan to the rear condenser? I didn’t know that was an option

[tsuter]

Originally Posted by echecsqueen

Do I need to add a fan to the rear condenser? I didn’t know that was an option

Maybe, but not yet. Address the switch first. If it is installed in a schrader valve then it can be removed without evacuating the system. Then put in a correct Trinary even if you don't use all the wires just yet. It belongs after the condenser though not in a vapor line.

I think you have and old Kuehl line if it is by the compressor and this location has been updated in recent years to go in the #6 line where it belongs. Unfortunately that means replacing two lines. #8 Compressor to Condenser and #6 Condenser to Drier or wherever yours goes.

[917_Langheck]

Originally Posted by echecsqueen

I don’t have a rear condenser fan- my rear condenser is mounted above my engine and only gets air cooling when in motion.

Actually, there is a rear fan already installed; also provides air to the engine, in motion or otherwise, so long as all the seals are intact. The Carrera fan draws some 1300 cu ft/min at 6,000 rpm, mas o menos.

[LJ851]

Originally Posted by 917_Langheck

Actually, there is a rear fan already installed; also provides air to the engine, in motion or otherwise, so long as all the seals are intact. The Carrera fan draws some 1300 cu ft/min at 6,000 rpm, mas o menos.

Depending on where I read the Carrera fan pulls 1300-1500 at 6100 rpm but that volume is actually liters per second which is a tremendous amount of air.

[tsuter]

Originally Posted by LJ851

Depending on where I read the Carrera fan pulls 1300-1500 at 6100 rpm but that volume is actually liters per second which is a tremendous amount of air.

It is a lot of air...when driving and at highway speeds. At stop lights and bumper to bumper it is not adequate for a modern R134condenser setup as the pressures will elevate too much resulting in poor cooling and or compressor cut out.

This is a good thread on some earlier condenser fan setups. Jim Sims(RIP) knew the science...but not all listen... and still argue the world is flat....
http://forums.pelicanparts.com/porsche-911-technical-forum/312760-adding-3-fans-rear-c-condenser.html

[echecsqueen]

A lot of my driving is “stop and go” city traffic or stopped (carpool line). My shut off switch is located in the line directly after the compressor on the high side. Not where y’all are saying it should be. It does have a shrader valve. Since my switch is before the condensers, does that change what the cut off pressures for the switch should be? Shouldn’t the hi cut off be even higher since the gas will be maximally compressed at my location?

[917_Langheck]

Originally Posted by LJ851

Depending on where I read the Carrera fan pulls 1300-1500 at 6100 rpm but that volume is actually liters per second which is a tremendous amount of air.

You are correct. Americans and their default to cfm strikes again.

[rwest]

I’m officially an advisor now!

Of course once you get my advice, you may fire me!

Thanks for the stickers Queen!

[echecsqueen]

Yay! Glad you got it Rutager- would never fire you!!
Proud to see you are using a sticker.