Author Topic: calibrated orifice DFS2A  (Read 9932 times)

Offline JWWebster

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Re: calibrated orifice
« Reply #20 on: June 14, 2009, 11:15:41 PM »
What are ya working on is it a walk in cooler or a ice machine or central air? WTF is it you are trying to charge? Get the suction pressure up to 68.5 PSI and that will give you 40 degrees F across the a-coil. that is a good thang. If you think the head pressure is getting too high watch your amp meter. This ain't rocket science. O0
« Last Edit: June 14, 2009, 11:22:54 PM by JWWebster »
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Offline patvac

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Re: calibrated orifice
« Reply #21 on: June 14, 2009, 11:22:25 PM »
i think you guys call it a mini split. 12000btu a/c unit where the condenser is outside to ground level and the evaporator is on the second floor

Offline Icehouse

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Re: calibrated orifice
« Reply #22 on: June 15, 2009, 01:29:21 PM »
When evacuating the system with both high and low side hoses connected to the compressor,
1.Open high side hand wheel on gauge manifold.
2.Leave low side hand wheel closed on gauge manifold. Start vacuum pump.
3.Observe low side gauge (should go into vacuum).
4.If it does not go into a vacuum reading, you have a restriction.
5.Continue operating till you have reached 29" hg. vacuum although using a micron gauge is the proper way (500 microns).
6.Let unit stand for 5 minutes, should be no change.
7.A slow rise indicates moisture (longer evacuation time).
8.Rapid rise, you got a leak.
NATE, NCCER, PHCC,HVAC Certified Instructor
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Offline JWWebster

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Re: calibrated orifice
« Reply #23 on: June 15, 2009, 02:27:30 PM »
I bet it has something to do with how the pipes connect from the evaporator to the outside condenser. How did you make up the connections?
May the hinges of our friendship
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About the icons: The beer is tip link, if a tech saves ya some money buy em a 6 pack. The small green square=personal message. The green dot is a link to my web page on appliance repair and other general BS I love to post. The letter sends me email.
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Offline Icehouse

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Re: calibrated orifice
« Reply #24 on: June 15, 2009, 03:32:19 PM »
I bet it has something to do with how the pipes connect from the evaporator to the outside condenser. How did you make up the connections?
>:( He mentioned that at the start. :tickedoff:
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline patvac

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Re: calibrated orifice
« Reply #25 on: June 15, 2009, 09:43:01 PM »
1/4 size pipe for pressure(copper)
1/2 for succion (copper)
they are shape like an Z but on the side

Sorry if i misconduct you
If needed i can add a picture

Offline JWWebster

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Re: calibrated orifice
« Reply #26 on: June 15, 2009, 09:55:30 PM »
Please add a pic because this is all becoming perfectly clear now. Your tubing is too small. The minimum is 3/8ths tubing for the hi side and 5/8th for suction.
« Last Edit: June 15, 2009, 09:59:06 PM by JWWebster »
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About the icons: The beer is tip link, if a tech saves ya some money buy em a 6 pack. The small green square=personal message. The green dot is a link to my web page on appliance repair and other general BS I love to post. The letter sends me email.
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Offline Icehouse

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Re: calibrated orifice
« Reply #27 on: June 16, 2009, 04:37:41 AM »
Please add a pic because this is all becoming perfectly clear now. Your tubing is too small. The minimum is 3/8ths tubing for the hi side and 5/8th for suction.
  :) JW, he is giving "Nominal" size which is inside diameter. Air Conditioning uses outside diameter  which is larger by (1/8). Therefore 1/4" ID is 3/8" OD and 1/2" ID is 5/8" OD.
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline Icehouse

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Re: calibrated orifice
« Reply #28 on: June 16, 2009, 05:05:51 AM »
Let's look at "old school" charging. That is "Ambient Temperature" plus 30. Convert this reading using a "Pressure-Temperature" chart to pressure. Example 80*F + 30 = 110* F. Assuming the refrigerant is R-22, you will read 225# (actually 226.4).
Low side reading should be equivalent to 40* F evaporator temperature, in this case 69# (actually68.5).  O0
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline Repair-man

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Re: calibrated orifice
« Reply #29 on: June 16, 2009, 05:20:28 AM »
Since he is dealing with very low ambient temps, this system may not operate correctly under 68 degrees outside. He really needs a heat pump capable of defrosting itself.
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