ReplyYou need to add more info. If you are saying the one liquid line temp is hot compared to the other that should point you in the right direction. Make sure coils are clean, condenser fan motors opperating and get super heat and subcooling
Regular Guest
Guys I have a 20ton Carrier package unit.Has 4 scroll compressors 2-per circuit (R22)and its couple of yrs old.#1 runs fine and #2 after 15mins goes into this alarm.It being a RTU and 100 plus(outside of Houston,Tx),my suction is 80psi w/both compressors running and 325 high side.Feeling the liq line and compareing to the other circuit it is just alittle warm where the other is hot.For a RTU,I think that the pressures is close,but when the unit shuts off my gages indicate under charge(suction does not peg,only 80-90).Guys I know that my descriptions amounts to someone just rambling on but for now this is what I have.
If someone could explain what causes this alarm and why the unit did not trip on high super heat which (I think) is the suction line being to hot for both.I want to try and understand HSST is.The unit is 48/50AJ w/VFD and has the Comfortlink controls.Does this unit show what the SST is on the display?Thanks for any directions from a misfit----CJ
More info to come Monday afternoon
Professional Member
You need to add more info. If you are saying the one liquid line temp is hot compared to the other that should point you in the right direction. Make sure coils are clean, condenser fan motors opperating and get super heat and subcooling
Professional Member*
Read the manual. The answers to your questions are in there.Originally Posted by CJ Courtney
Professional Member
I don't know about your unit, but it sounds like it's monitoring suction pressure via~transducer and doing a conversion to temperature (hence the high SST alarm)
this alarm would lead me to believe that your controller thinks the suction pressure is above it's alarm parameters for a set time.
Regular Guest
unit uses thermistors. you cannot troubleshoot refrigerant problems without information. what is your superheat, what is your subcooling. are thermistors accurate. comfortlink will show you what the tempertures of the thermistors are, if the machine is using exvs it will show you % open. so first off get the manual and read it then check your thermistors and get subcooling and superheat.
Professional Member*
I suppose he'll need the manual. Should be one of these.
Comfortlink version 2.x:
http://www.docs.hvacpartners.com/idc.../48_50a-2t.pdf
Version 3.x:
http://www.docs.hvacpartners.com/idc.../48_50a-3t.pdf
Version 4.x:
http://www.docs.hvacpartners.com/idc.../48_50a-5t.pdf
Version 5.x (Current):
http://www.docs.hvacpartners.com/idc.../48_50a-9t.pdf
Regular Guest
I would agree that reading the manual to familiarize yourself with the unit should be your first step. In the alarms and alerts section it will give you possible causes to your issue. I have alot of time on this particular unit so if you can provide more accurate details (sh/sc etc) i'm sure we can help you.
Professional Member*
Well CJ I would be willing to bet you have a version 2 or version 3 software in there . There are actual pressure transducers on the suction of the compressors but thermistors on the condenser giving you that discharge pressure reading. Start your unit up earlier in the morning when it`s cooler I think your alarms are happening at start-up. Yes it show`s the SST in temps.And just confirm your suction pressure transducers for accuracy.
Last edited by Dallas Duster; 08-28-2011 at 01:12 PM.
Regular Guest
Just a thought, this thing have hot gas??
Regular Guest
Thanks for all the replys and it has the verison 5 controls and does not have hot gas.This is the very first problem with this unit since it was installed about 2yrs ago right before school started.I did not know about the transducers,I will check that out and see what the actural gage psi is and see what the display shows.In the book under alarm code T123 all it says is high load(which the other circuit will run)and TXV problem.Guessing what "Goodlistener" is saying that the transducer is off from actural gage pressure.Thanks for some guidence and I will go through the manual and read alittle.Hope the school dist. appreciates the outside help,I do---Carroll
Professional Member
Hey CJ,
if it hasn't been done yet, you can increase your Hi SST alert delay from the factory setting of 10 minutes up to 30 minutes. this will allow the logic to give the unit a little more time to start bringing the RAT down before it begins to think the load is greater than the unit can handle.
Regular Guest
Where can I take alook at that?Guessing Configuration,just for my own info---CJ
Professional Member*
Configuration---Cool-----H.SST usually this will knockout both circuits sounds like there is something else going on to me. Good luck.
Also checkout the REV.R right before H.SST and make sure it says Yes, might save you some nuisance alarms in the future.
Regular Guest
Will guys I finally got a chance to check alittle futher into my alarm T-123.I have to say thanks to all for the advice of checking more and reading the book.This unit does not have a HSS temp sensor but it does have a suction transducer which looking at the display reading 183psi w/actural gage psi of 90 w/unit off.At the beginning of school just to many calls and not enought people to go around.thegoodlistener thanks for helping again and I will go back and check the display setting.Tks----CJ
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