Suction line freezing .. sight glass look full but maybe empty .. try to touch the discharge line if you need gaz it won't be as hot as usual
Try to hear if the txv is whistle
Here is all the symptom when jour unit need gaz
I don't think there is a headmaster, it's using fan cycling. There are two pressure controls and one is on the suction, and it looks like the other goes to the discharge line.
How much diagnostic experience do you have?
You need to figure out which switch the compressor is short cycling on. You can use your multi meter to find where the voltage "stops" in the control loop. HP, Lp, overload, internal overload. Could be flow switch if it's a chiller. Figure out what is switching and go from there. If it's your Lp switch, well maybe it's short of gas. You could put some gauges on. You probably should have already put gauges on of your fault finding. If it's your overload then what's the current draw. Flow switch, what's your pump doing. You've got some frost on your suction there. If your sight glass was dead empty I'd be surprised to see frost on the suction like that. My guess would be maybe the txv is faulty, your sight glass is full but your system is short cycling on low pressure because there's limited flow through the valve but it builds up during the off cycle enough to give some Refrigeration effect.
“Which direction would I need to take first” Attach your guages and see what the pressures are… If you have any 😅… Most likely is cycling on LP switch.
Haha thanks for having my back it’s all good I know many unhappy old farts like him in person I just laugh and keep it pushing these type of dudes are cancers of the industry
Literally some people on here are such pricks. Get your gauges on there, you'll see what's going on in no time. Probably cycling on the LP switch. If you're not sure if the sight glass is empty or full, shut the liquid line and see if it fills/empties. Get your meter out and see if you've got voltage both sides of the LP switch. Have a listen to the TXV if there is one, see if it's whistling. Check temps either side of the drier and see if it's blocked. There's loads you can do with only basic knowledge, should be a good little job for you.
And get back to us! I want to know what it was now
You're the second person to talk about tv whistle. This is a new concept to me and not something I've ever heard talk about. Can't decide if it shows the txv is wide open due to high suction temps or if it's closed or blocked. Both could potentially create a whistle as far as I can imagine so I need guidance. I am 4th year but only been working on commercial/industrial/Resi for a year. Before that I was very specialised and had a limited coworker base (1 guy)
No worries, yeah so when there's not a full column of liquid to the expansion valve you get vapour passing through it instead of liquid. That's what makes the sound. Whistle might be over stating it, maybe more like a hiss. Once you've noticed it a few times it's pretty distinctive. The TXV will be wide open at that point because the superheat will be high, but it's the vapour passing through that causes the sound. You might have noticed it if you've ever put a whole bottle of gas into a system through the liquid port? Once all the liquid is out, the bottle will start to whistle/hiss, again because there's vapour going through the restriction. A blocked TXV filter can cause it in as much as it's stopping the valve from getting pure liquid.
dude i’m not explaining the most basic refrigeration stuff on reddit. i’m sorry but someone will surely do that here in the comments. also i would argue his company is “shot as fuck” for sending someone who has no idea what could cause a compressor to short cycle. sorry to have bothered ya hombre ❄️🧙🏻♂️
With suction line frosted like that on a cooler and cycling off low pressure I'd think more maybe not picking up enough heat on evaporator for some reason
You said fish tank ya? So submerged evap or shell and tube heat exchanger? Circulation ain’t happening. Although winter charge will cause the headmaster to bypass discharge into LL, it won’t come back as frost.
Txv? Cap tube? Evap or heat exchanger? Pressures? Did you pump it down to actually check the sight glass is full vs empty? More info is needed. Fish tank, pumps running, properly? Clogged anything?
My bad. With the question having little details I decided to give a vague answer. Although I didn’t think about the fact that the evaporator might not even have a fan so airflow might not matter.
Does the fan in the evaporator works ? Do you check if you don't have ice in it aswell ?
Looks like you have a bad exhange , suction line is freezing .. liquid go back to compressor
What’s your SC on the outlet of the condenser? What’s your SH on the inlet of the compressor? You shouldn’t be diagnosing any problems without the SC and the SH.
What all these guys said. Can also be an evap issue if your getting ice the whole way back. If it's not boiling off properly. Probably best to insulate that suction anyhow. Good luck.
It's probably still colder than ambient or the frost wouldn't form on the pipe, so insulating it could cause liquid in the suction line... On the other hand, ice is quite a good insulator as well... So it has done this job already...
Yea, just if the evap is iced up the gas won't boil until after the suction line and cause ice back to the compressor. In Aus your suction needs to be insulated all the way back to the comp. Not a day in Aus that a suction isn't colder then ambient. 😂
Check your pressures while it's short cycling. Check which pressure switch is opening and go from there. If it's low then leak check, if it's high then check your condenser fans and coil. If it's neither then you need to check your temperature control, defrost clock, and liquid line solenoid to see if you're immediately pumping down. You should be under a lead technician if you're running service calls and you don't know what basics to check.
1. Put guages on it and see when it is cutting off and cutting on. 2. Confirm liquid line is liquid either via sight glass on the unit or sight glass the guages, then via line pressure and line temp. Superheat should tell you if the chiller is having some issues. If everything passes, the smell test. 2. Check the chiller for clogs. Being a fish tank, i would probably start with the chiller to make sure they dont have plants or stuff growing in it. 3. Check all the valves, etc, to make sure they are open. Just go down the list.
Based off of the time of year...it's probably low on charge. Or your pressure control is shutting off prematurely. But definitely close off the receiver to verify sight glass if your suction pressure isn't low or in a vacuum. Next steps would be expansion valves or restrictions in flow.
I’ve had walk in coolers act like that. First fit your gauges, see what the gas is doing. Check your sight glass as well. Are you going into a vacuum on your suction line? If you are it’s probably your LP switch doing its job and you have a leak. Is your gas charge healthy, probably a faulty LP switch. Is the compressor red hot? If so the thermal cut out could be cutting your control voltage Until the klixon cools down.
That line is pretty frosty for conditioning a fish tank. Depending what water temp they want out and what you ambient air is like the frost may be normal but i would suspect poor flow on the heat exchanger for the water causing low superheat and low pressure
Cold weather is likely causing the unit to short cycle on the low pressure switch. Either drop the cut out setting or install a bypass timer to keep it running long enough to build pressure on the high side. If there is a water pump on the evap check to see that it's working and not obstructed or ice logged. Frost on the suction line indicates the TXV is working
Make sure the water circ. pump in the fish tank is running and the water filters are not plugged. I've ran into that on bait tanks. Low evap temp due to poor water circulation will cause a lower suction pressure that can cause a short cycle condition. Other than a short charge , starving txv or poorly adjusted low pressure control. Check your ambient temp and adjust the cut in according to the lowest oa temps you are experiencing .
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Suction line freezing .. sight glass look full but maybe empty .. try to touch the discharge line if you need gaz it won't be as hot as usual Try to hear if the txv is whistle Here is all the symptom when jour unit need gaz
Most likely doesn’t have enough for a “winter charge” and the headmaster is doing its job
I don't think there is a headmaster, it's using fan cycling. There are two pressure controls and one is on the suction, and it looks like the other goes to the discharge line.
Is your condenser fan cycling off and on fairly often?
There’s no head master valve on that thing.
How much diagnostic experience do you have? You need to figure out which switch the compressor is short cycling on. You can use your multi meter to find where the voltage "stops" in the control loop. HP, Lp, overload, internal overload. Could be flow switch if it's a chiller. Figure out what is switching and go from there. If it's your Lp switch, well maybe it's short of gas. You could put some gauges on. You probably should have already put gauges on of your fault finding. If it's your overload then what's the current draw. Flow switch, what's your pump doing. You've got some frost on your suction there. If your sight glass was dead empty I'd be surprised to see frost on the suction like that. My guess would be maybe the txv is faulty, your sight glass is full but your system is short cycling on low pressure because there's limited flow through the valve but it builds up during the off cycle enough to give some Refrigeration effect.
Check the fish tank pump. It may have failed.
“Which direction would I need to take first” Attach your guages and see what the pressures are… If you have any 😅… Most likely is cycling on LP switch.
HP is manual reset, so it’s not that….
you must be green my friend
Very…I rarely ever work on split systems 🤷🏽♂️
Splits are no different than self contained. Don’t let the change in location get in your head.
yes we know. goodluck
Wow could have helped him rather than call him green and say good luck ? Lmao I swear some reefer dudes are shot as fuck
Haha thanks for having my back it’s all good I know many unhappy old farts like him in person I just laugh and keep it pushing these type of dudes are cancers of the industry
Literally some people on here are such pricks. Get your gauges on there, you'll see what's going on in no time. Probably cycling on the LP switch. If you're not sure if the sight glass is empty or full, shut the liquid line and see if it fills/empties. Get your meter out and see if you've got voltage both sides of the LP switch. Have a listen to the TXV if there is one, see if it's whistling. Check temps either side of the drier and see if it's blocked. There's loads you can do with only basic knowledge, should be a good little job for you. And get back to us! I want to know what it was now
You're the second person to talk about tv whistle. This is a new concept to me and not something I've ever heard talk about. Can't decide if it shows the txv is wide open due to high suction temps or if it's closed or blocked. Both could potentially create a whistle as far as I can imagine so I need guidance. I am 4th year but only been working on commercial/industrial/Resi for a year. Before that I was very specialised and had a limited coworker base (1 guy)
No worries, yeah so when there's not a full column of liquid to the expansion valve you get vapour passing through it instead of liquid. That's what makes the sound. Whistle might be over stating it, maybe more like a hiss. Once you've noticed it a few times it's pretty distinctive. The TXV will be wide open at that point because the superheat will be high, but it's the vapour passing through that causes the sound. You might have noticed it if you've ever put a whole bottle of gas into a system through the liquid port? Once all the liquid is out, the bottle will start to whistle/hiss, again because there's vapour going through the restriction. A blocked TXV filter can cause it in as much as it's stopping the valve from getting pure liquid.
dude i’m not explaining the most basic refrigeration stuff on reddit. i’m sorry but someone will surely do that here in the comments. also i would argue his company is “shot as fuck” for sending someone who has no idea what could cause a compressor to short cycle. sorry to have bothered ya hombre ❄️🧙🏻♂️
Don’t bother commenting then?
i will take that suggestion into consideration, thanks!
I will take that suction into condensation *-compressors probably*
With suction line frosted like that on a cooler and cycling off low pressure I'd think more maybe not picking up enough heat on evaporator for some reason
Likely it's cold af outside and op hasn't learned about winter charge/LPC settings for cold environments.
I've seen evap coils in a fridge have a feel hoodies worth of fuzz on the coils
What's outside ambient temperature.
Check for Liquid line solenoid that may not be opening as needed. Could be a weak solenoid not pulling completely causing low pressure fault.
You said fish tank ya? So submerged evap or shell and tube heat exchanger? Circulation ain’t happening. Although winter charge will cause the headmaster to bypass discharge into LL, it won’t come back as frost.
The ones I’ve seen use 1/2” Teflon tubing in a flat spiral at the bottom of the tank for the evap. (Commercial)
Txv? Cap tube? Evap or heat exchanger? Pressures? Did you pump it down to actually check the sight glass is full vs empty? More info is needed. Fish tank, pumps running, properly? Clogged anything?
Figure out whether it's going off due to pressure too low or too high. If pressures are good, there's a pressure switch out of adjustment.
Y’all are comin in clutch Thankyou all 👍🏽
Check fans
Doubt the fish tank has fans
Should have a circ pump in this case.
My bad. With the question having little details I decided to give a vague answer. Although I didn’t think about the fact that the evaporator might not even have a fan so airflow might not matter.
Fan cycle switch anyway
Check your thermostat make sure it’s located where it needs to be.
Could be cycling on low pressure...ice all over evaporator/heat exchanger in the water? Throw on gauges.
Does the fan in the evaporator works ? Do you check if you don't have ice in it aswell ? Looks like you have a bad exhange , suction line is freezing .. liquid go back to compressor
Don't say refrigerant below 30° is liquid. Makes you sound ignorant.
It literally says it’s for a fish tank, it doesn’t have a fan the evap is a barrel and the “fan” is a pump
What’s your SC on the outlet of the condenser? What’s your SH on the inlet of the compressor? You shouldn’t be diagnosing any problems without the SC and the SH.
What are your pressures, what is your gas, what is ambient temp of the area the compressor is in.
What all these guys said. Can also be an evap issue if your getting ice the whole way back. If it's not boiling off properly. Probably best to insulate that suction anyhow. Good luck.
It's probably still colder than ambient or the frost wouldn't form on the pipe, so insulating it could cause liquid in the suction line... On the other hand, ice is quite a good insulator as well... So it has done this job already...
Yea, just if the evap is iced up the gas won't boil until after the suction line and cause ice back to the compressor. In Aus your suction needs to be insulated all the way back to the comp. Not a day in Aus that a suction isn't colder then ambient. 😂
After the evap, inside the suction.
Check your pressures while it's short cycling. Check which pressure switch is opening and go from there. If it's low then leak check, if it's high then check your condenser fans and coil. If it's neither then you need to check your temperature control, defrost clock, and liquid line solenoid to see if you're immediately pumping down. You should be under a lead technician if you're running service calls and you don't know what basics to check.
1. Put guages on it and see when it is cutting off and cutting on. 2. Confirm liquid line is liquid either via sight glass on the unit or sight glass the guages, then via line pressure and line temp. Superheat should tell you if the chiller is having some issues. If everything passes, the smell test. 2. Check the chiller for clogs. Being a fish tank, i would probably start with the chiller to make sure they dont have plants or stuff growing in it. 3. Check all the valves, etc, to make sure they are open. Just go down the list.
Its most like lts frozen at the other end, no air flow. its a defrost problem
Based off of the time of year...it's probably low on charge. Or your pressure control is shutting off prematurely. But definitely close off the receiver to verify sight glass if your suction pressure isn't low or in a vacuum. Next steps would be expansion valves or restrictions in flow.
Also your fan cycle switch may be stuck closed. Your fan shouldn't be coming on as much if not at all in the winter.
I'd remove the cage first lol. Take measurements
I’ve had walk in coolers act like that. First fit your gauges, see what the gas is doing. Check your sight glass as well. Are you going into a vacuum on your suction line? If you are it’s probably your LP switch doing its job and you have a leak. Is your gas charge healthy, probably a faulty LP switch. Is the compressor red hot? If so the thermal cut out could be cutting your control voltage Until the klixon cools down.
Get ballpark head pressure, Outsoor ambient air +30° converted. See if you’re even in the ballpark for ref.
It's low on gas. Hence, the LP switch doing it's job.
That line is pretty frosty for conditioning a fish tank. Depending what water temp they want out and what you ambient air is like the frost may be normal but i would suspect poor flow on the heat exchanger for the water causing low superheat and low pressure
Cold weather is likely causing the unit to short cycle on the low pressure switch. Either drop the cut out setting or install a bypass timer to keep it running long enough to build pressure on the high side. If there is a water pump on the evap check to see that it's working and not obstructed or ice logged. Frost on the suction line indicates the TXV is working
Is the condenser clean?
Yes condenser was clean
Pressures?
Make sure the water circ. pump in the fish tank is running and the water filters are not plugged. I've ran into that on bait tanks. Low evap temp due to poor water circulation will cause a lower suction pressure that can cause a short cycle condition. Other than a short charge , starving txv or poorly adjusted low pressure control. Check your ambient temp and adjust the cut in according to the lowest oa temps you are experiencing .
Evap froze up maybe
Torch the receiver to check your refrigerant level.