How to set a fan cycling control on a refrigeration system
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- Опубліковано 6 лют 2025
- Fan cycling control set up for a refrigeration or air conditioning system to maintain a correct system head pressure.
Used when low ambient control is required or when a system has multiple compressors / fans.
Thank you for a very well laid out video! My question is how did you decide on the Saturated condenser temperatures of 85 to 105°F For your cut out and cut in the range. Thank you in advance
Great info for napa valley 32 F
Very instructive thank you very much,God bless
Thank you for the video
Where do you get the magic number 85F - 105 F and based on what you determined your differential pressure. I have been struggling with this a lot.
Thank you so much for info.
Wouldn’t mind seeing some more of these whiteboard video explanations.
Thanks patrick
any specific topic?
I know the quality of the video maybe suspect but I try to get an easy to understand point across.
cheers
Great explanation. Are these cut in and cut out settings for medium or low temperature evaporators? Thanks 🙏
yes, this can be used as the cut in and out on both medium / low temp applications.
👍
just remember to set it up for the refrigerant that your using.
latent fusion thank you so much. I am fairly new to commercial and residential refrigeration. Please keep making more videos.
Do you have go back in the late spring and late fall to adjust it
Once the control is set it will maintain the head pressure year round with no need for adjustments.
Good staff
Amazing
is a fan cycle control just for air condition?
It can be for air conditioners but I utilized it more when working on refrigeration equipment during periods of low ambient outdoor temperatures.
Thank you.does it have anything to with the furnace the fan cycle control?
And how long can the thermostat be on hold and not on run?
how about Freon 502 , i want the temp. inside the cold store between -18 -13> is it right to adjust the low pressure 20 psi and diff 12 psi
Hi RS,
So I'm suspecting your using farenheit?
Keep in mind most condensing units can only operate within a certain range unless they have been modified. Check the lowest saturated temp with the equipment info.
To achieve your temperature settings try 20 psi in and 8 psi diff to start. Monitor the cutout and increase as needed.
A liquid to suction heat exchanger may need to be added to the system. Good luck and let me know.
@@latentfusion2563 thanks ...no data available in the unit....i am in saudi arabia>>>any how i adjust the low pressure 20 psi>>>>> high pressure 300 psi>>>>diff 15 psi>>>>inside cold store thermostat setting -8c >>>ir running normally>>>.is the setting right?
@@rs3682 just a question, does the room have a thermostat if so then it will be your primary temp control and the low pressure control will be a safety control. If you want the room colder then adjust the thermostat.
latent fusion u r right...yes i have,,,,,another question if u pls, what standard or normal pressure for freon 502 means what suction and discharge rate?thanks again
@@rs3682 suction pressure is determined by what saturated temp you are trying to achieve. Refer to a pressure temp chart. You can also download the danfoss phone app.
Head pressure is determined by the ambient temp around the condenser. As a general rule the condenser will add 25f to 30f to the ambient. So if it is a 70f day the condensing unit will be condensing at 100f. On a pressure temp chart for r502 it should be around 215 psi. Download the app and have a play.
Hope this helps.
The pressures and temperatures will very day to day as conditions change.
What happened to the printer set up video? Looks like a lot of your stuff has gone private.
Typically we are taught to set the differential between 30 and 50 psi. I've been in the field since 1995 and as of yet no one that I've spoken with has ever suggested a 66 PSI differential setting nor have I ever felt the need to set it that high. So if you don't mind providing a little feedback where did you come up with the 66 PSI differential setting?
Thank you for your question.
I have based my numbers on the saturated condensing temperature of the refrigerant that i am using.
Since all refrigerants have a different pressure/temperature relationship I didnt want to recommend a rule of thumb like 30 - 50 psi.
Standard condensing units have a T.D. across the condensing coil of 30f
So at an ambient of 55f we will be condensing at 85f. At 75f ambient we will be condensing at 105f.
All condensing units have a recommended refrigerant temperature range in order to achieve the greatest net refrigeration effect.
Some new equipment have lowered this range by increasing the size of the condenser slightly.
My example in the video was for r404a, blended refrigerant. If I was to use other refrigerants they would work out as follows.
R134a in @135psi out@ 79psi diff of 56psi
R22 in @ 209psi out@ 155psi diff of 54psi.
R12 in @ 129psi out@ 91psi diff of 34psi.
So to re-cap the difference between my settings and yours is about 2f in saturated condensing temperature.
Although my pressures seem higher than the R.O.T. that you have been taught it means next to nothing when it comes to the effective operation of the equipment.
I have spent a lot of time in canada so I have always preferred getting a bit more run time out of my fan.
@@latentfusion2563 thank you!
Wow. You were prepared to answer that question, lol. Good answer