it just shut off!!
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it just shut off!!
from 830 to 12 to drop it 8f
When it comes back on would be the best time to adjust the charge.
will the superheat skyrocket during the heat of the day? or should it stay pretty much the same?
yeah i know
so far its holding 70f in the room, but it has been overcast and raining today too. so far so good
Got a full list of temps/pressures?
nope still rainin, but its running about 35-45 minutes during cycles
Did you trim the charge to 15F superheat?
i got in contact with goodman tesh support, they said the system required a .73 orifice(which i installed) and a superheat of 22f because uf the humidity. i did this yesterday and it has worked the best today but like i said it was overcast and raining. anyways here are the reading-
suction temp=62f
liquid line=83f
condensor in=77f
condensor out=88
evap in=66
evap out=53
lowside=72psi
highside=175psi
this was taken at 10pm and it was wet, 95% relative humidity
Low delta-T's... high suction... low head... I'm thinking this compressor is inefficient.
The only other possibility would be a leaking reversing valve, but you checked the suction pressure on both sides of the reversing valve and they were identical.
I found a Goodman service manual:
http://www.hvacpartsshop.com/asc%20series.pdf
hi
ur air handler is 3.5 tons&condenser is 3 tons there is a miss match
gary tanks for the link&the way u guide him
i think every thing is clear now
The air handler is rated at 2.5 to 3.5 tons, based on 400CFM per ton. It is currently set on low speed (1000CFM) which should result in a low suction pressure... but the suction pressure is in fact high.
One more thing we can try is to measure the temps of the two cold pipes at the reversing valve. If the valve is leaking across, the temp on the side towards the compressor will be considerably higher.
would a leaking reversing valve of an inefficient conpressor still pull a vacuum when the suction line is closed?
you asked if it would pull a vacuum, it did but it didnt do it fast and it wasnt much. ive seen systems with a clogged orifice and they would pull a hard hacuum very quickly.
also as a bit of info, the tech at goodman said he didnt think the highside pressure was low. but as im learning more of how the system works, it seems it would need a higher pressure to keep the refriderant from boiling in the liquid line, right?
Where are you measuring the evap air in and air out temps? Best would be at the air handler.
the return air is right above the air handler about 1ft and the closest out is at a vent 3ft away. its a downdraft.
i cant measure the out temp right from air handler because it mounts to the floor so i have to use the closest vent
3 ft away should be accurate.
in reading your post in a/c 101, you explained that the boilding of refrigerant in the evaporator removes the heat from the air(which i understand) but i also understood it to say by raising the pressure in the condensing coil it returned the refrigerant back to a liquid(by increasing pressure and removing the added heat) so i guess my question is, is the system raising the pressure enough to maintain the proper liquid state?
my next question is, by overcharging and having the wrong orifice, could that have damaged the valves in the compressor?
R22 at 175psi gives you a saturated condensing temp (SCT) of 93F. In order for the liquid in the liquid line to boil off, its temp would have to be higher than 93F. Its temp is 83F. Not going to happen... and since the two temps go up and down together, it can't happen.
Did you measure the temps of the suction lines entering and leaving the reversing valve?
it sounds like you are closer to getting it. if not what I would do is recovery the refrigerant, return both units to goodman specs, evacuate according to goodman instructions. Then weigh in the factory charge and weigh the additional charge according to what Goodman says - for example .68 oz or each additional foot beyond 15 feet. I have seen it stated to recovery refrigerant for less then 15 feet also.
If this does not give you a good operating ac then call goodman and say what the ....
The other thing is where is the expansion valve? I do not have much experience with Goodman but it seems all manufactures have gone with txvs since the high SEER. Could you have a 13SEER Cond and a 10SEER Evap coil?
A txv might work better anyhow
the epansion orifice is in the front of the case. i am pretty sure its a 13seer handler too. and as far as it having a txv, the handler i removed had a txv and i didnt like it. i would prefer to have an orifice simply because its just less to question its functionality.
to me a txv is much easier. I've always had good luck with weighing in a charge - estimating distance if I did not install the lineset. Check subcooling and everything works out.
Since the txv meters the refrigerant by suction temp I'd think you get better performance.
As for fouling the txv it is just as likely to plug the orifice with a dirty lineset.
this is true. everyone prefers different things, ive just had better luck with orifices.
i cant see a difference in the temps on the reversing valve. also, when i would pump the system into the condensor to change the orifice, it would hold the pressure in the highside and not bleed back to the lowside, so i think the valve is fine. as for the compressor, im not sure.
Yep... everything points to the compressor.
is it likely to have 2 compressors, from 2 separate units, built by different companies, be inefficient? i guess thats my doubt.
one being used but worked when removed other than a leak in the condensing coil(which i fixed) and the other being brand new.