Just changed a bad compressor in this unit it was originally an R-12 unit i replaced it with R-409A and the unit will not get down to temp and the compressor is kicking out on high heat i did clean the condenser coils any ideas?
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Re: Delfield bay marie M/N 18693pt S/N 65629M
Very most likely overcharged on freon. With R-409-A, you can not charge by sight glass. Do the ambient plus 30 method if it is a txv. That will get you close. If it is a cap tube, charge to an evap temp of about 20 degrees. then watch it. Make sure it makes temp and shuts off.
Hope this helps
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Ok so in this case the most likely reason the relay burnt out is because the compressor is tight and having problems starting so it burnt relay. Need to determine what LRA (locked rotor amps) is by looking on data plate on compressor and see if amp draw is at or very near the LRA spec. if it is the compressor is bad
If the fans run we know it aint the defrost timer and you are getting power to the compressor so that means you have a wire done burned off one of the compressor terminals hopefully or ya might need a compressor. Probably just a burnt wire. These are pretty tough units. Diagram and run info
In every case I've been exposed to in this situation, it is a result of the units location. Hot air from the compressor and condenser coil moves across the unit and heats it. Usually the unit is stuck in a "Hole" under a counter where air circulation is very poor. Check this out.
Possible solution to original question at top of page: Recently worked on a Delfield F2FH with the exact same problem. Would get to 12 degrees and then go up and down either to -10 degrees or up to 12 to 55 degrees. Although I cleaned the condenser coil of some dust it was not the problem. There was no icing of the evaporator either. The defrost timer was also working. There was icing of the lines coming off the compressor but this was simply a symptom of the real problem. After checking everything out carefully and talking more with the customer about how the unit was fluctuating in temperture I noticed something that I had not paid much attention to as a possible factor in the problem. It seems a previous technician had worked on the unit and was very sloppy in his work as he did not put many of the screws back in place after taking the unit apart. Two screws that he did not put back were the ones that secure the overhead outside front panel where the door switches are located. As a result the switches were only making a hap hazard connection with the striker pads on the top of the doors. Whenever the owner moved the unit or, wiped the panel or, even opened the door the top service panel would move slightly out of allignment causing one or both door switches not to contact the striker plates. This in turn shut down the evaporator fans inside the freezer compartment which then only allowed cold air to drift to the bottom of the inside of the unit. The temp control sensor, mounted inside at the top near the evaporator fans, was reading tempertures inside the freezer compartment warmer at the top as all the colder air was at the bottom. On this unit there was only about a half inch of tolerance on the door striker plates so if they were not alligned properly the fans did not come on. So, check your door switches and see if they are engaging. One or both of your doors may have dropped to low to fully engage your door switches due to worn bushing or hinges (each door will only turn half the fans on inside); your striker plates may be worn cracked or out of allignment; your top panel is loose and moving the strikers out of allignment. Don't forget to manually test the evaportor fans to see if they are all working. Do this by opening both doors and pressing both door switches. If the fans do not come on suspect a bad switch which controls the fans which failed. If all the fans come on the problem is in the contact of door to striker plate. If one or even two fans do not come on test the fan itself. The air must circulate insde to keep a proper temperture. I hope this was helpful.
GDM-41 would be the unit model number???
If you want to get a compressor model number that would be on the compressor tag on the compressor itself. I would not bother with a True part number just get the Copeland or Tecumseh number off of the compressor and get a replacement from a local wholesaler. On this old box do not rule out brittle or shorted wires. I haven't had success with converting a box like this to R-134a unless I change the entire condensing unit and would tend to go with an interim replacement like Hot Shot or R-409A or something like that. The box probably won't last long enough to make R-134a conversion viable.
I wouldn't recommend R-134A for an existing unit conversion. The head pressure will probably be a bit high and a complete oil change will be necessary. I don't know what model you have or what the nickel plating on the plate looks like now but an R-12 machine will be pretty old. If you must convert I would use one of the interim replacements for R-12 such as R-414B also known as Hotshot, possibly R-409A, or Frig-12 that was made as a interim for the automotive a/c applications. Not knowing your availability to these various refrigerants I might also recommend checking the automotive a/c replacements to see what is available. As for amounts with such a small system and a TXV metering device I would just add 22oz as long as the head pressure doesn't get over say 175psi during freeze mode.
How was this unit originally equipped? TXV? Use only a TXV OF CORRECT size. In refrigeration if you have a 6000btu rating you do not use a 1/2 ton valve you use a 1/4 ton (3000btuh) at most and would need consulting with an engineer to arrive at the correct valve.
SO was the TXV the other fellow replaced an OEM valve? If not this may be the problem as most TXV's off the shelf are designed for walk-in refrigeration Not Reach ins. An OEM valve may be the trouble here.
Now not to stress the TXV but also the compressor (what was the original model?) Make sure it is designed for the particular heat range and size for this application. As you probably know 1 size compressor designs for AC will not be OK on Refrigeration at same BTU rating.
Call Del field and verify what they are using or recommending for this unit. model and Seal no required and the existing model and SN.
Also to my knowledge a receiver is not required and in fact will only add to your trouble. Receivers are for changes (wide differences) in condensing temperature and pressure. Never saw an application for one with a condenser designed from factory for indoor use with either type of expansion device.
If you need Del fileds number email me at email@example.com and in th subject line enter delfield?.
You can clean the condenser while it is running or you can unplug unit . most of the time you can use a nylon brush to brush off the condenser. If it has not been cleaned in a while you may need some sort of compressed air to blow through it. If units are in restaurant and by fryers or have greasy buildup on them you will need to unplug unit and spray some degreaser on it then rinse with water. It is important to clean the condenser, the part with fins and is located by compressor, because a dirty condenser will shorten the life of the compressor.
I would expect at the very least a heater circuit around the freezer door. Some of the commercial units also have sprung doors to keep the doors firmly shut which you could check by opening the doors. Door heater circuits are normally very reliable and it would be worth checking the voltage is getting to them, they are also a pain to change out.
Hope this helps.