thanks everyone for good advice.
i wanted to know if anyone was even close to my location - could work out a flat fee for travel.
Check out the Site Map for a contractor in your area. A market tech would be best for you.
Vince :anyone: in the Dublin Georgia area ?
Did you pump it down and check all the TXV strainers?
A lot of good responses.
Here's my :.02:...
A possible airflow problem has been mentioned. It's possible the discharge air plenum up the back wall of the case is plugged up with dust & lint, blocked by ice buildup or both. Such blockage will reduce airflow and air velocity.
Proper discharge air velocity is critical to get these cases to run right. The velocity for this model should be around 225 Ft/min (FPM). The tech needs a proper velocity meter like an Alnor 8100 Velometer Jr to check them.
The manufacturer doesn't recommend running theses case with off-time defrost (as they are now set up since the reverse air has been disabled). I doubt that the current 25 minute defrost times are nearly sufficient...more likely they need 60 minutes, but by then your meat will have gone south.
I suggest either fixing the reverse air defrost or adding electric defrost heaters with proper termination thermostats. Hot gas defrost is a quicker defrost, but with a single compressor is asking for troubles. The manufacturer only recommends HG defrost for parallel rack systems.
Your also not going to be able to run your discharge air down to 26 degrees. With just off cycle defrost. You need those fans to reverse to melt ice, or add some heaters as Ice was saying.
You will have to settle for around 32 degree discharge air unless you do something about your defrost.
Tech came out more adjustments and DA was at 28*. He was setting the superheat by the gauges at the compressor. What I don't get is how he kept adjusting the valve to get lower DA temp and didn't even care that the tstat was set at. He was told my his manager to set 4 - 45 min defrost . The thing is it cost me $$$ just in travel time plus the time he is here. Total of 3 tech came out so far ... All have their own way of doing things... I called and told them all I want is my product temp less than 40.
I would expect to see him at the TXV if he's adjusting the superheat. It's at the entrance to the evaporator coil. That's the coil at the bottom of the case. Is he making the adjustment there ? The TXV has a stem on it to adjust with a wrench. He should have a temperature probe at the TXV sensing bulb and should also have a pressure gauge as near as possible there.
Do you know if the fans are on or off in defrost mode ?
Fans r on in defrost. I had to tell him that there is pressure gauge hook up near the TXV. But he said its fine he got gauges hooked up near the condenser . He was adjusting TXV and had the temp probe near where the bulb would be for TXV
lets invite every store manager in this site, so next time we service their stores they can show us where to hook up the gauges and check the superheat, or even better, give them a tool bag so they can do their own troubleshooting and call us only when they need some "freon":rolleyes:
You can have the bean-counter types that don't care about their equipment and how to do some preliminary and basic checks.
Those bean counters are the ones that call me out at 1AM on iced up cases when what they SHOULD be doing is taking care of it.
yeah i even told him don't you need the coil cleaned with no ice to adjust the super heat. i don't think he cared.
As soon as he walked in i told him i was superheat at 6 - 8 *. 3 different tech 3 different ways. arggggg....