I've been running into this a lot this week. Below freezing Vsat, wildly high superheat and super low suction pressure. But, it's been in the low to mid 60s and raining buckets for a couple weeks. My fresh out of school thinking is constantly telling me to add, but after passing leak checks and using common sense, I have held off. Thanks a bunch for these videos GFM, you've provided me with so much help and in this case some validation too.
Hello sir i want to know that my ac is r32 1.5 ton. It has pipe size 3.5 meter. I had to cut 2.5 because of gas leakage pipe bend. Now i charge gas. My room 30c and outside 32 Suction pressure is 125psig stable when start. In sometime running ac room temperature down to 16c suction pressure show 105psig. Then it is not go to 12c and autocut as before. I think i charge 570grm gas. Manufacturer sticker 650gram standard charge. What should i do? When i charge 650grams suction pressure is 145psig. Is it hamful for machine? And if i charge some less amp rr down 5.1amp but normal is 6.6amp. What should i do. I see that 110 psi pressure compressor run smoothly. Very less noice. I uselly use 24c only. I need to charge the ac with more gas?
Hello sir i want to know that my ac is r32 1.5 ton. It has pipe size 3.5 meter. I had to cut 2.5 because of gas leakage pipe bend. Now i charge gas. My room 30c and outside 32 Suction pressure is 125psig stable when start. In sometime running ac room temperature down to 16c suction pressure show 105psig. Then it is not go to 12c and autocut as before. I think i charge 570grm gas. Manufacturer sticker 650gram standard charge. What should i do? When i charge 650grams suction pressure is 145psig. Is it hamful for machine? And if i charge some less amp rr down 5.1amp but normal is 6.6amp. What should i do. I see that 110 psi pressure compressor run smoothly. Very less noice. I uselly use 24c only. I need to charge the ac with more gas?
@@grayfurnaceman Hello sir i want to know that my ac is r32 1.5 ton. It has pipe size 3.5 meter. I had to cut 2.5 because of gas leakage pipe bend. Now i charge gas. My room 30c and outside 32 Suction pressure is 125psig stable when start. In sometime running ac room temperature down to 16c suction pressure show 105psig. Then it is not go to 12c and autocut as before. I think i charge 570grm gas. Manufacturer sticker 650gram standard charge. What should i do? When i charge 650grams suction pressure is 145psig. Is it hamful for machine? And if i charge some less amp rr down 5.1amp but normal is 6.6amp. What should i do. I see that 110 psi pressure compressor run smoothly. Very less noice. I uselly use 24c only. I need to charge the ac with more gas?
There are low ambient controllers that you can add to units to help with this if it remains a problem. It is just a head pressure control switch that will cut off or reduce fan frequency to raise head pressure thus giving you a closer to actual operating pressures.
zeke montgomery This video is not for setting up an air conditioner for low ambient conditions. It is to check out charge on days that have low ambients. I will be doing one on fan cycling switches when I get a chance. GFM
Here in western Washington if you waited until it was 70 degrees or higher to do just maintenance calls you’d be waiting until heat wave when no cool calls come in. What do you think about doing maintenance/tune calls around 55degrees outdoor ambient minimum? I know it’s not desired but would you say it’s acceptable?
I also have that problem, (not quite as bad) in eastern Wa. 55F is pushing it, but I have done it. Blocking of condenser necessary, but there is no way to simulate a load on the structure. There will be times when you will miss a charge issue, GFM
So if putting a temp probe inside the airflow of the condenser to see what the temp split be be ok too? If its a 20 degree diff from the indoor it can be another verification?
You are trying to imitate 80F+ ambient. The way to determine this is to increase the head pressure as read in condensing temp to 20 to 25 degrees above an ambient temp of 80F. Hope this helps. GFM
If you are charging gas in low ambient, you may indeed need to warm it. The best way to do so is to place the cylinder into a bucket of warm water. Hope this helps. GFM
I think this may have answered my son's question who keeps asking me if the refrigerant is always moving the same speed through the system. I think what I got out of this video is the greater the compression ratio then the more refrigerant that's being moved. The lower the compression ratio then the less refrigerant that's being moved. Am I correct or am I misunderstanding something?
GFM I think you didn't understand what I was getting at I do understand as you describing your last text your troubleshooting methods what I'm saying is you can only use the subcooling method on an expansion valve job and not on a fixed orifice or capillary tube
Guy Hakverdi I can't think of any way to run the refrigerant thru the set. Also, fixed orifice device air conditioners sometimes will have bubbles in the sight glass when the charge is right. GFM
I'm a rookie in the field so I am coming across things I haven't experienced before. a few days ago I checked a system that had the same superheated (25) and sub cool (18) as the system you have in this video , but it was a warm day. I had a saturation of 40 degrees. what is causing my high sub cool and super heat
Since 1977 when I got into this business. Subcool tells you another part of the system health. When I am servicing a system, I am looking for anything out of the ordinary. It leads me to problems that may not be obvious at first glance. GFM
I'll never forget this old building, 1900s, at my work place that had a room with a few server racks full of servers. They had two large Carrier window units to keep the room and equipment cool. I will never forget when I found one of the units with over an inch of ice on the evap coil! It was iced up to the point the front bezel couldn't be removed! I was very happy when all those servers were moved to a proper facility with proper computer room HVAC equipment! LOL
This tells you absolutely nothing about if the system is appropriately charged. Not liking your numbers? Just slide the board over a little more until you like the numbers smh. He even gives so far as to say you should come back when it's warmer to check again. If your company has you out there checking AC's in Temps lower than 65F instead of using this time to prepare your tools for the season ahead just bail
I've been running into this a lot this week. Below freezing Vsat, wildly high superheat and super low suction pressure. But, it's been in the low to mid 60s and raining buckets for a couple weeks. My fresh out of school thinking is constantly telling me to add, but after passing leak checks and using common sense, I have held off.
Thanks a bunch for these videos GFM, you've provided me with so much help and in this case some validation too.
down to earth presentation done with clarity. Great job sir. Bottom line...you made an impact. I learned from you. Thank you.
Welcome
GFM
thank you GFM, this confirms that my previous diagnostic is correct. I will add a fan cycling so that customers can cool under 15c (60f)
what a great teacher learned so much from you without the hands on training just added to what I do know perfect teacher I love the a/c work
Thanks for the support.
GFM
Hello sir i want to know that my ac is r32 1.5 ton. It has pipe size 3.5 meter. I had to cut 2.5 because of gas leakage pipe bend.
Now i charge gas.
My room 30c and outside 32
Suction pressure is 125psig stable when start. In sometime running ac room temperature down to 16c suction pressure show 105psig. Then it is not go to 12c and autocut as before.
I think i charge 570grm gas.
Manufacturer sticker 650gram standard charge.
What should i do?
When i charge 650grams suction pressure is 145psig. Is it hamful for machine?
And if i charge some less amp rr down
5.1amp but normal is 6.6amp.
What should i do.
I see that 110 psi pressure compressor run smoothly.
Very less noice. I uselly use 24c only. I need to charge the ac with more gas?
I was waiting for this so much. Thank you .I was in that situation so many times. You helped me you can believe
Luc Dumouchel Welcome
GFM
Hello sir i want to know that my ac is r32 1.5 ton. It has pipe size 3.5 meter. I had to cut 2.5 because of gas leakage pipe bend.
Now i charge gas.
My room 30c and outside 32
Suction pressure is 125psig stable when start. In sometime running ac room temperature down to 16c suction pressure show 105psig. Then it is not go to 12c and autocut as before.
I think i charge 570grm gas.
Manufacturer sticker 650gram standard charge.
What should i do?
When i charge 650grams suction pressure is 145psig. Is it hamful for machine?
And if i charge some less amp rr down
5.1amp but normal is 6.6amp.
What should i do.
I see that 110 psi pressure compressor run smoothly.
Very less noice. I uselly use 24c only. I need to charge the ac with more gas?
@@grayfurnaceman Hello sir i want to know that my ac is r32 1.5 ton. It has pipe size 3.5 meter. I had to cut 2.5 because of gas leakage pipe bend.
Now i charge gas.
My room 30c and outside 32
Suction pressure is 125psig stable when start. In sometime running ac room temperature down to 16c suction pressure show 105psig. Then it is not go to 12c and autocut as before.
I think i charge 570grm gas.
Manufacturer sticker 650gram standard charge.
What should i do?
When i charge 650grams suction pressure is 145psig. Is it hamful for machine?
And if i charge some less amp rr down
5.1amp but normal is 6.6amp.
What should i do.
I see that 110 psi pressure compressor run smoothly.
Very less noice. I uselly use 24c only. I need to charge the ac with more gas?
I would charge by superheat if it is a fixed orifice expansion device. Consider 5 to 7 C superheat.
GFM@@vineetsehgal4738
There are low ambient controllers that you can add to units to help with this if it remains a problem. It is just a head pressure control switch that will cut off or reduce fan frequency to raise head pressure thus giving you a closer to actual operating pressures.
Very relevant video , great timing, I've seen this quite a bit.
Thank you for the tips.
Very nice, you are a good teacher. Thanks for your videos.
DC Rickerson Thanks for the support.
GFM
Hence..install fan cycling switch.
zeke montgomery This video is not for setting up an air conditioner for low ambient conditions. It is to check out charge on days that have low ambients. I will be doing one on fan cycling switches when I get a chance.
GFM
No fan cycle switch ? Thanks for your videos
GFM, good stuff
Great video...
What about using the fieldpiece charging jackets?
I can't say from personal experience, but they are viable.
GFM
Only for txv
thanks for this vid...
Here in western Washington if you waited until it was 70 degrees or higher to do just maintenance calls you’d be waiting until heat wave when no cool calls come in. What do you think about doing maintenance/tune calls around 55degrees outdoor ambient minimum? I know it’s not desired but would you say it’s acceptable?
I also have that problem, (not quite as bad) in eastern Wa. 55F is pushing it, but I have done it. Blocking of condenser necessary, but there is no way to simulate a load on the structure. There will be times when you will miss a charge issue,
GFM
So if putting a temp probe inside the airflow of the condenser to see what the temp split be be ok too? If its a 20 degree diff from the indoor it can be another verification?
You can check the split across the outdoor coil but it will be much lower than the indoor coil.
GFM
This might be a dumb question What ambien temperature are you mimicking when blocking half of the condenser fan?
You are trying to imitate 80F+ ambient. The way to determine this is to increase the head pressure as read in condensing temp to 20 to 25 degrees above an ambient temp of 80F.
Hope this helps.
GFM
do u need to warm r22 freon in conditions under 60 degrees because having hard time pumping in freon in these 55 degree weather or below
If you are charging gas in low ambient, you may indeed need to warm it. The best way to do so is to place the cylinder into a bucket of warm water. Hope this helps.
GFM
thanks
I think this may have answered my son's question who keeps asking me if the refrigerant is always moving the same speed through the system.
I think what I got out of this video is the greater the compression ratio then the more refrigerant that's being moved. The lower the compression ratio then the less refrigerant that's being moved. Am I correct or am I misunderstanding something?
GFM I think you didn't understand what I was getting at I do understand as you describing your last text your troubleshooting methods what I'm saying is you can only use the subcooling method on an expansion valve job and not on a fixed orifice or capillary tube
Can you also use your nice gauge set that has a sight glass ? To figure out if it needs charge.
Guy Hakverdi I can't think of any way to run the refrigerant thru the set. Also, fixed orifice device air conditioners sometimes will have bubbles in the sight glass when the charge is right.
GFM
What head pressure should I try to achieve at low ambient temperatures with R410A and a piston ?
In the absence of manufacturer instructions, I would be looking for a condensing temperature of 20F + ambient.
GFM
Thanks bro
GFM, what do you feel is the lowest indoor temp you can have to do this? Thanks for all the vids
I really don't like below 75F.
GFM
Got it thank you
whats your opinion on fieldpiece charging jacket.
Works good.
GFM
I love it
I'm a rookie in the field so I am coming across things I haven't experienced before. a few days ago I checked a system that had the same superheated (25) and sub cool (18) as the system you have in this video , but it was a warm day. I had a saturation of 40 degrees. what is causing my high sub cool and super heat
Have a question can i email u
Hi l am look were the temperature probe of my air conditioning is . The make of the air is domestic 2200
Since when can you do subcooling on a fixed orifice system expansion valve job yes
Since 1977 when I got into this business. Subcool tells you another part of the system health. When I am servicing a system, I am looking for anything out of the ordinary. It leads me to problems that may not be obvious at first glance.
GFM
This would explain why the window unit in my computer room ices up on a cooler 70 degree day.
ESDI80 Computer room units need to have head pressure controls to work properly. Hope this helps.
GFM
I'll never forget this old building, 1900s, at my work place that had a room with a few server racks full of servers. They had two large Carrier window units to keep the room and equipment cool. I will never forget when I found one of the units with over an inch of ice on the evap coil! It was iced up to the point the front bezel couldn't be removed! I was very happy when all those servers were moved to a proper facility with proper computer room HVAC equipment! LOL
ESDI80 I'll bet you were happy.
GFM
Adding a Fan cycling in the condenseur unit can solve this problem?
Head pressure control yes. Fan cycling control, no. Worst possible method of controlling head pressure.
GFM
grayfurnaceman why the fan cycling Is not good. Can u explain me pls? Thnx :)
I have been meaning to do a video on this. The head pressure varies so widely that suction pressure cannot be controlled.
GFM
grayfurnaceman with a piston, i agree but i Will Wait for this video ;) thnx for ur Time and tutorial
every time i get a unit with low suction pressure, and high head its always one of these trane units you are showing in this video.
***** Uhh, low discharge pressure and high head? Please explain.
GFM
55 psi on the low side and 225 psi on high side with a dry bulb of 72
This tells you absolutely nothing about if the system is appropriately charged. Not liking your numbers? Just slide the board over a little more until you like the numbers smh. He even gives so far as to say you should come back when it's warmer to check again.
If your company has you out there checking AC's in Temps lower than 65F instead of using this time to prepare your tools for the season ahead just bail
What head pressure should I try to achieve at low ambient temperatures with R410A with EEV?
I would be looking for around 300#.
GFM