[icemeister]

My thought was when I get my SH in decent the I would go the Evp and tune it in.(any thought on this line of thinking? )

You want to get the compressor suction superheat between a minimum of 20ºF and a max of about 40ºF. If it exceeds this range and the evaporator SH is already at 6-10ºF, then you need to address the heat gain in the suction line. If the compressor SH is too low and the evaporator SH is between 6-10ºF, then you either need to adjust the evap SH higher or add a suction/liquid heat exchanger.

On 1 time looking at the system slowly add (0.25 lb each time and waited 20 min after each 0.25 lb ) up 2.25 lb (giving a totally systems charge of 10.15 lbs (7.9+2.25) a with only a 8 f drop to SH (81 f – 8 F = 73 F) in the end.

System trip on high HP let set 45 min turn back on ran apx 2 min and trip on high HP.

Recovered 0.5 lbs at next, wait 30 min SH 73 F.

SC of 54 F with OA 71 F Hi side 182 Low 12 SH 51

Hold the phone there Skippy.

You're saying you kept adding refrigerant to get the superheat down? ...and the unit tripped on the HP control? ...and you had to receiver 1/2 lb to keep it running? ....and then you had 51ºF of liquid subcooling?

You need to review how a commercial refrigeration system with a TEV and a receiver is properly charged and adjusted. I suggest reading the Heatcraft Refrigeration Systems Installation and Operation Manual (H-IM-64) starting with p.32.

When you charge a system like this, if the ambient is below 75ºF block the condenser enough to get the head pressure over 200# or so (to insure the Headmaster is not bypassing) and add enough refrigerant to just clear the sightglass. This is your minimum operating charge. Then (if the system has a Headmaster type condenser flooding control), you'll need to add more refrigerant for cold weather operation. That's included in the Heatcraft manual as well.

These systems will only give you up to about 5ºF liquid SC and that is all the subcooling you're ever going to get no matter how much refrigerant you add....until you get to the point where the receiver is 100% full and you start stacking up liquid in the condenser. This is apparently where you were at when the HP control tripped.

Get a new, correctly sized TEV in there and start over from the top of the page.

 

[fcs]

Box is full of product that variable found past records doesn’t (inventory is pretty constant).

Records show in past every time OA has a major Temp change they rest Defrost cycles.

We (they)want is get box so it not having trouble every 6 or 7 times or more time a year.

Pre Mrg of Kitchen (been there since building open) Box is runs fine for a month maybe more then it goes up to 30 F or 45 F many work “OK” for a few weeks or months then trouble Mrg said thing ran fine till the comp burn.

This kitchen crew I is good about not leavening door open.

Use Inferred thermo walls and door seem ok inside and out. Tape K probe to walls for 1 hr seem ok 3 month ago box seams where check and resealed. Door seal looks good.


As for SC I have a only 1 note for SC and that was near the end Heatcraft Tech Support told me “this is low Temp we don’t worry about subcool” so I didn’t . I thought this was strange, any thought .

I wrote to the side at the end SC 54 I believe it was 54 temp give a SC of 77 F

Again sorry for my bad note.

 

[rayr]

Wondering why you would waste the time and effort weighing in charge on a field charged system?????? Superheat settings should be taken and adjusted (if necessary) after box is stabilized and almost at setpoint.

 

[fcs]

Hold the phone there Skippy.

You're saying you kept adding refrigerant to get the superheat down? ...and the unit tripped on the HP control? ...and you had to receiver 1/2 lb to keep it running? ....and then you had 51ºF of liquid subcooling?


Yea I did and when I did it I said this is stupid.
In my defense, and if this were a trail I would say that is a p!$$ poor defense. I got focused on get it up and running

So for that move I ask for a charge of desperate and in a hurry And Plead guilty to 1 count of 1st degree Count of Stupid. I’m sure there may be more to follow.

 

[fcs]

Wondering why you would waste the time and effort weighing in charge on a field charged system?????? Superheat settings should be taken and adjusted (if necessary) after box is stabilized and almost at setpoint.
__________________

System had been work several times in past and Ref added. wanted to see were she was.

And Pre Heatcraft tech support she was over.

 

[icemeister]

Yea I did and when I did it I said this is stupid.
In my defense, and if this were a trail I would say that is a p!$$ poor defense. I got focused on get it up and running

So for that move I ask for a charge of desperate and in a hurry And Plead guilty to 1 count of 1st degree Count of Stupid. I’m sure there may be more to follow.

Mistakes are a big part what experience is made of.

Stupidity is not asking questions and not learning from your mistakes.

Because you're here asking and learning, you're OK.

 

[yotaman16]

per heatcraft means NOTHING because as was stated you need to add charge for your proper winter operation, and heat craft doesn't no exactly how much u need to add.. So the unit probably wasn't overcharged when u said extra gas was in there it was probably the winter charge

 

[sarpanch2001]

23 deg SC that will tell you got full liqued going to txv .overcharge . what cause proper ref not flowing back to pump ? only thing left txv

 

[fac 213]

Okay Mr Air 2 spare, Maybe I was not completely correct, when I said their might be the wrong piston. The correct name in a nozzle, Each Bohn coil comes with two. They are in a little plastic bag inside the coil, located in the TEV section.One is for R-12, and the other is for R-502, R-22 .If you do not have the correct NOZZLE, you will not have the proper refrigerant flow into the coil.

 

[fcs]

Got call into the building on another situation and got the Comp unit model #
Heatcraft Model LHT014L6C

 

[powell]

Got call into the building on another situation and got the Comp unit model # Heatcraft Model LHT014L6C

This model is the capacity I mentioned in post # 16 so no need to repeat it again. It is an outdoor unit that comes standard with CC HTR, Head Pressure control flooding valve, 5.5 lbs receiver @ 90%, 5/8 x 3/8 line connections. Could have other options that were added.

Change the TXV to optimize the performance. I still think it will struggle, in the hotter ambients, to maintain -10.

 

[sarpanch2001]

This model is the capacity I mentioned in post # 16 so no need to repeat it again. It is an outdoor unit that comes standard with CC HTR, Head Pressure control flooding valve, 5.5 lbs receiver @ 90%, 5/8 x 3/8 line connections. Could have other options that were added.

Change the TXV to optimize the performance. I still think it will struggle, in the hotter ambients, to maintain -10.

do not waste time follow POWELL

 

[sumdumguy]

If you recover the refrigerant in a clean jug you can reuse it. Set the system for a 110 degree head temp.

trick: i keep a cylinder in a deep vacuum @ all timesx2