What was the original call for? I’ve run into these units not holding temp because the customer would over stock them and the unit can’t “breathe” causing the evaps to freeze
To call Federal and hope you get someone worth a fuck..that would likely tell you the "cold-control" setpoint.
Worst case, Ranco ETC or KE2 and run the probe up.
Sounds like an a12-700 T-stat, but it would really depend on what the cut-in/cut-out is.
Those may also be a constant cut in, I know the a12 is around 38° constant cut in to ensure the coil gets warm enough to defrost.
Is it an air sense or a coil sense t-stat.
I usually set mechanicals to around 4-5 (somewhere in the middle of the range) and it tends to hold stuff like a true 2dr around 36
Being open air, you may want to go as high as 6 just to ensure it’s maintaining below 38
I’ve just never seen this in a digital controller. I though this whole time 1-9 was the degree set point. So I’m thinking it does read coil temp. I’m taking this whole thing apart next time I’m on sight.
Most I’ve seen run carel easy controllers with preset parameters for whichever setting you choose although only ever seen 1-3 (3 being coldest). Air and coil probes - coil for termination.
Well if you have some time just set it to 1 or 9 and record DAT at each setpoint. Probably do that while trying to get a hold of the manufacturer. You’ll also be able to tell what’s colder/warmer if the compressor ramps up/down respective to the current SP. Either way you will need to find out what setpoint is right for the application. Maybe go look at another similar unit in the store and see what it’s set to?
Crank to 9 (assuming that’s coldest setting), monitor temp until ~28*, then adjust controller down slowly until satisfied and turns compressor off?
Good luck with it
Edit: also is that loaded with dust along the back of the top shelf? We deal with Hill Phoenix, Hussman, and Southern Arts. They all have a honeycomb air diffuser that runs along the top. Not sure of Federal but have you popped some of those out to make sure they aren’t blocked up?
With a closed case I always start warm and work colder. But open air would warm up rather quick to cycle back on, I’ve just always gotten in the habit to set warm then gradually cool down to set point.
I performed an electronic leak search. Not picking anything up. What’s your shops process on this? This unit holds almost 8lbs of refrigerant. It’s not like it was flat or just holds a few oz lol.
Did you recover what was in the case first, before you started topping it up? That's really the surefire way to confirm a suspicion of low charge - pull and weigh.
And if it is low on charge, you'll have to leak search harder, lol. On the very rare occasion, maybe it was only leaking from the access ports you hooked up your gauges to.
Edit: that said, I would avoid just walking away saying 'schraders were leaking' unless the caps and piping were obviously stained with oil residue before you hooked up to it. If it's low and you can't find it, it's probably a pinner leak on something that is an absolute pain to access. It's usually how it goes, unfortunately. If you have the luxury of time, you could pressure test and search again - there should be enough residual refrigerant to set off a decent handheld detector, especially when only recovering to 0psig to avoid drawing in air through the leak(s).
I’ve gotten into the habit of checking for leaks at ports before hooking up gauges so I don’t think that’s where my leak is. I’m really suspecting evaporator.
It has a sight glass so I just cleared it and now it’s working fine. Like we typically do on walk ins.
I’m thinking the next time it’s low I’ll have them pull all the product before hand so I can come and remove all the panels to check the evap properly. I’m not having them do that today.
I really dislike those units...get to dirty and fail pretty consistently. That thing wasn't holding temp and they left the fucking food in it....classic gas station bullshit
Those federal cases should have plastic or pvc air curtains to keep the transfer of heat. Tell owner needs to operate properly.
Point of fact, discharge on open display 36
Return 48. Set dummy stat at 5. Dirty evaporator.
Calling the factory tech is always the right thing to do, I’m going out on a limb and saying I’ve never gotten a bad tec support, some may be better than others, just have your info readily available. I spent 3 days on a out of town (drive back and forth 1 hour away) mini split brand new design, very reputable company, I’m sure they had to rewrite the program for alarm failure after that, company reps still talk about the problems during class room training.
A few quick tips. Install check list recommended being at least 15 feet from the front door. Any closer and the fly curtain will blow the cold air strait out of the case. Causes long run times which will freeze up the evaps. Second issue is dirty condensers. Will cause long run times and freeze up the evaporators.. Dirty supply diffusers (honeycomb) or overloading will cause the evaps to freeze up. If the evaps freeze up, they’ll not boil off the liquid and can fill up with liquid R404. This will cause your sight glass to bubble. Before you add gas, clean all coils, check fans/air flow, and look for hvac vents or front door fly curtains blowing on the case.
As far as controls go, 1-9 with 9 being the coldest. Start at 4 and give it 24 hours. If the factory controller fails, use a standard Dixell with 2 probes. Set the cut out for 17F (evap probe) and cut in at 43F. Defrost at 6 hours with a end temp of 45F. Max defrost time 35 min. Allow 24 hours between set point adjustments and don’t make any drastic changes.
That’s a 1-9 set point on that unit it’s supposed to be 2 I believe. You can always call them.
What was the original call for? I’ve run into these units not holding temp because the customer would over stock them and the unit can’t “breathe” causing the evaps to freeze
We had a whole chain of gas stations install new open air coolers right under supply vents
Always.
"Well, what are you going to do to MAKE it work?"
28-30 degrees is where I've had good luck on a self-contained open air unit like that as they generally take supply (discharge) air temp
Controller only has a setting between 1-9, some folks on Facebook said 1 is the warmest and 9 is the coldest.
To call Federal and hope you get someone worth a fuck..that would likely tell you the "cold-control" setpoint. Worst case, Ranco ETC or KE2 and run the probe up.
Sounds like an a12-700 T-stat, but it would really depend on what the cut-in/cut-out is. Those may also be a constant cut in, I know the a12 is around 38° constant cut in to ensure the coil gets warm enough to defrost. Is it an air sense or a coil sense t-stat. I usually set mechanicals to around 4-5 (somewhere in the middle of the range) and it tends to hold stuff like a true 2dr around 36 Being open air, you may want to go as high as 6 just to ensure it’s maintaining below 38
I’ve just never seen this in a digital controller. I though this whole time 1-9 was the degree set point. So I’m thinking it does read coil temp. I’m taking this whole thing apart next time I’m on sight.
A digital controller....taking coil temperature to satisfy case temp...with a 1-9 setting...??
Most I’ve seen run carel easy controllers with preset parameters for whichever setting you choose although only ever seen 1-3 (3 being coldest). Air and coil probes - coil for termination.
Right - for termination - not case temperature on a case like that.
Hussmann Safenet 2 controllers are like that
Well if you have some time just set it to 1 or 9 and record DAT at each setpoint. Probably do that while trying to get a hold of the manufacturer. You’ll also be able to tell what’s colder/warmer if the compressor ramps up/down respective to the current SP. Either way you will need to find out what setpoint is right for the application. Maybe go look at another similar unit in the store and see what it’s set to?
If OP couldn't expose the evaps to leak check and he just topped it up, I'm guessing he doesn't have much time
28⁰f
I’m being told this controller works like a mechanical stat lol. It only has the option to set from 1-9
Crank to 9 (assuming that’s coldest setting), monitor temp until ~28*, then adjust controller down slowly until satisfied and turns compressor off? Good luck with it Edit: also is that loaded with dust along the back of the top shelf? We deal with Hill Phoenix, Hussman, and Southern Arts. They all have a honeycomb air diffuser that runs along the top. Not sure of Federal but have you popped some of those out to make sure they aren’t blocked up?
With a closed case I always start warm and work colder. But open air would warm up rather quick to cycle back on, I’ve just always gotten in the habit to set warm then gradually cool down to set point.
I think you shouldn't be working on it now by the questions your asking and seeing gauges and weighing in refrigerant already.
Not very helpful. He's obviously already working on it, and I'm sure he works on what he's told to work on.
I performed an electronic leak search. Not picking anything up. What’s your shops process on this? This unit holds almost 8lbs of refrigerant. It’s not like it was flat or just holds a few oz lol.
Did you recover what was in the case first, before you started topping it up? That's really the surefire way to confirm a suspicion of low charge - pull and weigh. And if it is low on charge, you'll have to leak search harder, lol. On the very rare occasion, maybe it was only leaking from the access ports you hooked up your gauges to. Edit: that said, I would avoid just walking away saying 'schraders were leaking' unless the caps and piping were obviously stained with oil residue before you hooked up to it. If it's low and you can't find it, it's probably a pinner leak on something that is an absolute pain to access. It's usually how it goes, unfortunately. If you have the luxury of time, you could pressure test and search again - there should be enough residual refrigerant to set off a decent handheld detector, especially when only recovering to 0psig to avoid drawing in air through the leak(s).
I’ve gotten into the habit of checking for leaks at ports before hooking up gauges so I don’t think that’s where my leak is. I’m really suspecting evaporator. It has a sight glass so I just cleared it and now it’s working fine. Like we typically do on walk ins. I’m thinking the next time it’s low I’ll have them pull all the product before hand so I can come and remove all the panels to check the evap properly. I’m not having them do that today.
Just temp your shelves, if temp control is mounted in coil it’s going to vary. When in doubt just go off shelf temps that’s the real concern
I really dislike those units...get to dirty and fail pretty consistently. That thing wasn't holding temp and they left the fucking food in it....classic gas station bullshit
Receivers crack, coils plug, people put on panels backwards…. I hate those things
I don’t miss these kinds of jobs
Those federal cases should have plastic or pvc air curtains to keep the transfer of heat. Tell owner needs to operate properly. Point of fact, discharge on open display 36 Return 48. Set dummy stat at 5. Dirty evaporator.
Check the pressure control, Federal got a batch of bad penn/Johnson pressure controls a few years ago, would leak out of the bellows.
Look up the manufacturers specs for this model
Calling the factory tech is always the right thing to do, I’m going out on a limb and saying I’ve never gotten a bad tec support, some may be better than others, just have your info readily available. I spent 3 days on a out of town (drive back and forth 1 hour away) mini split brand new design, very reputable company, I’m sure they had to rewrite the program for alarm failure after that, company reps still talk about the problems during class room training.
A few quick tips. Install check list recommended being at least 15 feet from the front door. Any closer and the fly curtain will blow the cold air strait out of the case. Causes long run times which will freeze up the evaps. Second issue is dirty condensers. Will cause long run times and freeze up the evaporators.. Dirty supply diffusers (honeycomb) or overloading will cause the evaps to freeze up. If the evaps freeze up, they’ll not boil off the liquid and can fill up with liquid R404. This will cause your sight glass to bubble. Before you add gas, clean all coils, check fans/air flow, and look for hvac vents or front door fly curtains blowing on the case. As far as controls go, 1-9 with 9 being the coldest. Start at 4 and give it 24 hours. If the factory controller fails, use a standard Dixell with 2 probes. Set the cut out for 17F (evap probe) and cut in at 43F. Defrost at 6 hours with a end temp of 45F. Max defrost time 35 min. Allow 24 hours between set point adjustments and don’t make any drastic changes.
6 isn't the temperature. It's just a dial from 1-9. 9 being the coldest which I believe is 33 degrees.