Running Pressures!

[G_Young]

Hi, im new to air conditioning, and after a month ive been left for a while just on maintenance...

Wondering if somebody could sort me out with a list of good running pressures for gases when in cooling.
i,e R22-60 psi on lowside etc...

R404A, R407c, R410A, R22, FX56, R134A etc... please?! thanks.

[rbartlett]

Hi, im new to air conditioning, and after a month ive been left for a while just on maintenance...

Wondering if somebody could sort me out with a list of good running pressures for gases when in cooling.
i,e R22-60 psi on lowside etc...

R404A, R407c, R410A, R22, FX56, R134A etc... please?! thanks.

best use temperatures rather than pressures

cheers

richard

[slingblade]

This is entirely dependant on the running conditions of whatever plant you are working on at the time of measurement. if you have a chiller on r22 for example running with a suction of 100 psig and del. of 250 psig with water at +18 deg c, it will differ to an identical chiller with water at +8 deg c, or -8 deg c. pressures and temps. are very relative to each other and a good understanding comes from practical experience, which does not come overnight.

i understand that you would like a kind of quick reference guide for guage readings but im afraid it does not work that way. best bet is to log every plant you work on and jot it in a diary. the more you see the more you will gain in knowledge. it's how i started.

[puddleboy3]

As already pointed out its not that simple. Try checking the suction superheat and the discharge superheat to make sure your system is operating correctlly. Simple and effective if you know how. Problem i think with new engineers comming up the ranks are that they are missing the basic refrigeration points. Whats your thoughts?

[US Iceman]

Try checking the suction superheat and the discharge superheat to make sure your system is operating correctly. Simple and effective if you know how.

Darn good advice. Those two readings and the pressures will provide a lot of good information if it is interpreted correctly.

The key point is to check pressures and temperatures on any system. You are doing that when you determine the suction and discharge superheat.

[Andy]

best use temperatures rather than pressures

cheers

richard

I would advise not connecting gauges to splits at all

Measure the air on and off the indoor unit, compare this to the suction temperature. On the condenser side measure the liquid temperature and the hot gas temperature.

Then if you have a noticable problem it's time for the gauges.

Otherwise if you do a maintenance once a year, connect and disconnect gauges the charge will end up a bit short over a few years (even with quick disconnects).


Hope this helps

Kind Regards Andy

[rbartlett]

I would advise not connecting gauges to splits at all

Measure the air on and off the indoor unit, compare this to the suction temperature. On the condenser side measure the liquid temperature and the hot gas temperature.

Then if you have a noticable problem it's time for the gauges.

Otherwise if you do a maintenance once a year, connect and disconnect gauges the charge will end up a bit short over a few years (even with quick disconnects).


Hope this helps

Kind Regards Andy

Indeed Andy

At gatwick as part of Carriers' onsite team we were forbidden to fit gauges to splits during routine maintenance

cheers

richard

[leftjobrunning]

I would advise not connecting gauges to splits at all

Measure the air on and off the indoor unit, compare this to the suction temperature. On the condenser side measure the liquid temperature and the hot gas temperature.

Then if you have a noticable problem it's time for the gauges.

Otherwise if you do a maintenance once a year, connect and disconnect gauges the charge will end up a bit short over a few years (even with quick disconnects).


Hope this helps

Kind Regards Andy

Well said. And a lot of customers are now looking for a maintenance every 3-4 months!!!
This advice should apply to all smaller equipment, in fairness most faults can be diagnosed without ever putting the guages on.

[SkyWalker]

o.k guys i completely understand where you are coming from but there must be some sort of guide pressures ou are looking for, i mean if you go on a LG MultiV or Daikin VRV2 course's they say your looking for about 115 psi suction, 400 psi discharge, i beleive daikin actually recommend slightly higher but the difference is like 10 psi! (R410a) would you guys look for this pressure always on R410a?

what about R22 and R407c????? i understand this pressure is only a guide but hey if you visually check the system and can find no faults and you get to the gauge stage you need to know what pressures to look for.

also on the new Bigger air con kit you can measure the voltage off the pressure sensors and with a nice little graph read the pressures = no refrigerant wastage + no bloody burn, i mean everyone hates connecting to R410a right

[Brian_UK]

o.k guys i completely understand where you are coming from but there must be some sort of guide pressures ou are looking for, <snip>

You are back to the "use temperatures" statement.

[taz24]

o.k guys i completely understand where you are coming from but there must be some sort of guide pressures ou are looking for, i mean if you go on a LG MultiV or Daikin VRV2 course's they say your looking for about 115 psi suction, 400 psi discharge, i beleive daikin actually recommend slightly higher but the difference is like 10 psi! (R410a) would you guys look for this pressure always on R410a?

what about R22 and R407c????? i understand this pressure is only a guide but hey if you visually check the system and can find no faults and you get to the gauge stage you need to know what pressures to look for.

also on the new Bigger air con kit you can measure the voltage off the pressure sensors and with a nice little graph read the pressures = no refrigerant wastage + no bloody burn, i mean everyone hates connecting to R410a right

You seem to know what there is to know. You have asked for advice and it has been given. Either use your own skill, kowledge and experience or listen to what people say to you.

taz.

[SkyWalker]

what about R22 and R407c?????

i was helping the guy out while also asking a question to save on a new thread! only trying to help and be helped!

Either use your own skill, kowledge and experience or listen to what people say to you.

i am here to learn as is everyone else and i am more than willing to listen to what people have to say!!

[puddleboy3]

There are to many factors to take into consideration to be able to say a A/C system should be running @ this pressure or temperature! Going way back to the start of the thread suction superheat and discharge superheat are a good point to start if there are both ok then your evaporator and condensor are working to there full potential no matter what type of refrigerant you are working on or what type of system you are working on. On the Daikin VRV II course they only state pressure/temperature comparrisons between the refrigerants not what the Daikin systems should be running at. On the course i was on they did let you connect a service checker to the training room system to let you see what it was running @.