Ak900 Negative superheat

[petersami]

I just got these guages, and i'm loving them so far, but i'm kinda at a loss as to why the superheat is reading negative. i read the manual and it said something about the dew point being lower than it should, if i understood correctly. I'm a new tech and loving it so far. I'm just trying to do my very best and just a little nervous about going digital.


thanks for any help

[IceWhiteice]

Make sure you have it on the right refrigerant. Im not being funny, but I have done it. Enjoy them, I know you will.

[jtrammel]

Make sure it's on the right refrigerant. You can't have negative superheat.

[itsiceman]

If you have a blend it might be seeing a negative number but it's not negative SH.
I think digis are the only ones I've seen that will display a negative number vs a blank in either the SH or SC value but since others don't display a calculation you wouldn't be able to easily read a discharge line super heat with other styles

[petersami]

i only do residential r22//410, so far on r 22 i've seen a negative super heat. i know in the manual it says something about the temp being below the dew point for the refrigerant or something to that effect. im just paranoid about these gauges, they're totally new to me and nobody i work with has heard of digi cool. i got them because of all the praise they receive on here, and they seem to be rather sturdy and accurate.

also any tips on getting the clamps to read a little faster. i got the uei package with the clamps, but they seem to adjust a little slow, longer than the 2 minutes the manual says.

thanks for any input.

[IceWhiteice]

Dont worry, these gauges are the best on the market. It might take a week or two to get used to them but when you do, they will make you a more accurate and better tech. Dont worry about the name- you made a great choice.

[petersami]

i appreciate it. i put them on my titan 4's oddly yesterday when i was finishing up at a clients house, i couldnt return any refrigerant back into the system. suddenly my manifold would "drain" out of the vapor line. odd as hell. i've just got some paranoia going on because its a whole new system and i dont have anything to check against. other than my old analogs.

i'm a green tech like i said i'm just trying to the best i can. i know these gauges have some awesome reviews and like i said thats why i got them. they're so simple to use, i love that!

[rayr]

In the first place you do not "Read" superheat. You read temp, pressures, (SST) and then calculate the superheat. You cannot have "Negative superheat". CDave would have a field day with this. (Trying to figure out what dew point has to do with superheat??)

[petersami]

In the manual for the Ak900 it explains why you get a negative superheat reading. the explanation is what is over my head. I understand how to calculate superheat. i'm trying to understand better why my 900's gave me a negative reading.

[marc5180]

Firstly Are your sensors in the correct position to read superheat?


Im wondering if you have liquid flood back to your compressor? I've seen mine go to a negative superheat before and that's normally the case.

[jtrammel]

In the first place you do not "Read" superheat. You read temp, pressures, (SST) and then calculate the superheat. You cannot have "Negative superheat". CDave would have a field day with this. (Trying to figure out what dew point has to do with superheat??)

The dew point of the refrigerant is the suction saturation temperature, the bubble point is the condenser saturation temperature. This comes into play when you use blends that have a temperature glide. Dewperheat and Bubcooling.

[petersami]

so should i be concerned about my gauges doing this. yes ive got my hoses hooked up right and yes ive got the temp probes on correct lines.

[lytning]

So what happens when you put the gauges on an other system?

so should i be concerned about my gauges doing this. yes ive got my hoses hooked up right and yes ive got the temp probes on correct lines.

[jtrammel]

so should i be concerned about my gauges doing this. yes ive got my hoses hooked up right and yes ive got the temp probes on correct lines.

How exactly is it reading? Something like SST 36, SLT 35, SH-1?

[petersami]

So what happens when you put the gauges on an other system?

ive tired it on other systems and it didnt do it. but then on my last call yesterday i left it on a system for while and when i left it showed negative sh.

[petersami]

How exactly is it reading? Something like SST 36, SLT 35, SH-1?

yes exactly but more like SST 66 SLT 77 Sh-22


I'm just making up numbers but i know theyve been higher. i know my probes are kinda slower than i prefer, it took them about 10 minutes (literally) to adjust to take the temp split over a filter dryer.

[Core_d]

Your flooding negative SH... Also known as SC

[jtrammel]

yes exactly but more like SST 66 SLT 77 Sh-22


I'm just making up numbers but i know theyve been higher. i know my probes are kinda slower than i prefer, it took them about 10 minutes (literally) to adjust to take the temp split over a filter dryer.

Sounds like Something's wrong with it. Email Doug Lockhardt at Digi-Cool.com.

Something's also wrong with the system if you have a SST of 66*F

[petersami]

even with high pressure like 130psig my sst is going to higher, correct?

[petersami]

also i'm using the ak900s on my titan manifold. could i have done something wrong when swapping them?