How to install a home refrigerator compressor!
My father Damien William Murphy or Bill who passed away a few years ago was instrumental in helping me choose a trade and helped get me started with some fundamental skills even though he was never really a good mechanic himself. He knew enough to use his skills to promote his used appliance business. If needed he could figure out that a thermostat was bad or a defrost timer. if a refrigerator was a tad short on refrigerant he could top it of as we say in the industry. But when it came to major surgery he really struggled and had to count on people who worked for him. Installing a home refrigerator compressor was not his strong point. His skills were in other area’s.
Putting a compressor in a home refrigerator takes skill in order to do it correctly. There are so many things that can and will go wrong if your not careful.
How to install a home refrigerator compressor.
1. Get the correct compressor there are so many compressors it is easy to make a mistake. I used to have a book that gave me all the specs so it was easy for me to swap compressors when needed.
2. You must have all the right tools: recovery machine and tank, gauges, torch and correct solder and flux, charging scale or cylinder, freon, sandpaper, copper tubing tool or coupling if needed and basic hand tools.
3. Recover the refrigerant and remove the old compressor. I like to take notes to make sure everything goes back correctly, note the wires and location of the pins on the compressor. You can cut the tubing from the solder ports on the compressor just past the point where there is no solder or for people with good skills clean the joints apply the correct flux and heat and pull the tubing from the compressor ports is the most common way. Cutting the joints can lead to extra work. When pulling the tubes apply even heat, make sure there is no gas. Be prepared once and a while there will be a flare up from the oil. Keep your face away where gloves and safety glasses and once the tube does come out dont let go till it cools a little or it might stick. By the way your going to be holding the tubing with pliers not your hand and only squeeze hard enough to hold on do not distort the tubing. Some compressors have an extra set of lines to help with oil cooling when you find these cut them do not try and heat and pull. These tubes are at the bottom of the refrigerator compressor. Sometimes there is a special factory O.E.M type connection.
4. Once the tubes are removed from the compressor and everything is noted and marked so you will remember to put it back correctly pull the pins for the compressor feet or remove the screws which ever it has. if you cant do this part then stop here.
5. Place the new compressor where the old one was lock it down and remove the rubber stubs on the tubing.
6. Clean the ports on the compressor inside and out. use sand paper on the outside and a small tubing brush on the inside or use a rolled piece of emery cloth. There are 3 ports on most compressors, two are suction ports and one is high side. One suction port and high side line should line up with your tubing. Place a schraeder stub tube in the low side port that is not being used.
Do not put the tubes all the way in yet. This is where i like to put the flux on the tube so none of it gets in the system. If the tubes with solder on them already don’t go in don’t worry we are going to heat them and help them in.
7. Change the filter drier, this a another skill. Clean the tubing at both ends, cut the tubing on the inlet with a tubing cutter. Cut the capillary tube by making a grove with a sharp file and breaking it by hand the rest of the way. You might want to practice this on something else you will want to get this right.. Install the the new filter drier that has a access fitting stub on it as well as a step down for the cap tube.
I like to use 35% or better solder on home refrigerators because most of the time your joining metal to copper. You can use regular brazing rods on the copper to copper joints. Once your all brazed up put a 100 psi of nitrogen and check your joints with soap. no leaks then use your vacuum pump to evacuate down to 30 on your gauges.
8. How to charge a home refrigerator. I am going to share with you my knowledge of charging thousands of capillary tube systems in my career. You can not do it by feel or by guessing. In a pinch you can try and sometimes you’ll be OK and other times your going back several times to make adjustments.This is another part of the job that separates the technician from the hack. Are you going to get paid and get out or stay there all night trying to get the thing to cool.
You are going to need a small charging cylinder. A very good electronic scale is adaquite but there is still to much room for error.
small capillary tube refrigerators have a very small charge that must be right to work all year round in differant tempuatures. you can charge a refrigerator in the summer and it may not work in the winter.
A charging cylinder eliminates that, that is why I made so much money in the 1980’s with my service business i had the process down packed. if it says 16 oz then that’s what you put. You dont even have to wait around much when your done. Heres how to do it correctly. If you dont have a charging cylinder and your charging a R-134 system that takes about 16oz use a small can with no oil, dye or sealant from the auto store.
Put the proper amount of freon in the cylinder in liquid form with the dial set at the pressure the freon is at presently. Close your gauges and disconnect the vacuum pump. Connect the hose to the bottom of the cylinder and bleed a tiny bit of freon thru the hose. If your using self sealing hoses dont worry about this next step. If you are using self sealing hoses then open your high side valve to charge liquid into the high side connected to your filter drier. If your not using self sealing hoses then charge thru the low side and remove the high side hose soon as the pressure starts to rise up out of a vacuum. Put in the full amount in liquid and let the charge settle for a 5 or 10 minutes so the liquid can become a gas in the system. This is such a small amount of liquid it will not wash out the oil. do not stop the flow of the charge with your gauges at this point your going to want to shut the cylinder or can because the liquid in the hose is part of the charge. This is why we disconnected the high side hose if your not using self sealing gauges so that you do not loose part of the very small very critical charge.
While your waiting for the charge to settle please connect the wires correctly based on your notes. If you can please put oil in the fan motor( How to oil a sealed one piece motor). Start your paper work and start putting things in order.
When your satisfied you can start your compressor. If everything looks OK then it’s time to remove your gauges. if you used self sealing hoses then remove the high side first. Then open the high and low on the gauges in order to let the refrigerant in the hose get sucked into the low side on the compressor preserving the charge. Remove the hoses put the caps on, put back the shield if there was one. And were finished.
I hope this helps and i will edit as time goes on to add things i may have overlooked if there is any.
Getting back to the story!
I was young and still was not a full time service mechanic but I was working in a refrigeration factory building small marine refrigerators and i went to my dads shop and there he was with a local guy who helped him once and a while trying to install a household refrigerator by using a stick of 5% brazing rod and liquid low temperature flux mainly used for 50\50 or 95\5. apparently they had been at it for some time with no success. I could tell he was frustrated and his helper was surely high and not much help at all so I made sure I did not chuckle or this would not have went well! I know my father and if he was a little younger he would have thought it out better. Not that he was that old but once he got over fifty and his eyes were bothering him and he would get headaches by bending over to long there was no way this was ever getting done and it does not help to have a helper on heroin, so I offered to help.It turned out he had the right flux and solder to braze copper to metal right in his shop, it was the helper who insisted it could be done the other way. i cleaned everything up and brazed the joints with silver and paste flux. It made me happy to help and he was happy to get that little nightmare over with, of course he scolded the helper for telling him that would work when he knew it would. After all he did go to Apex!