Refrigerator Commissioning. Add oil and removal
Once the system is fully charged and a set of controls, operation of the equipment in the average boiling conditions. Compressor oil-the level must then be checked.
All new compressors receive operating oil, responsible for production, but it does not allow the oil trapped in components and controls and refrigerant. This is the reason why the oil level should be checked and oil added to the system during installation or commissioning.
Only brand and grade of oil specified by the manufacturer of the compressor should be used. Oil have unique characteristics for high pressure, temperature and load, especially those used for low temperatures.
Large compressors oil-level, pointing to the inspection glass, located in the crankcase. If compressors are used in parallel, sometimes sight glass in the middle of the oil equalizer line.
During operation, the oil level in the crankcase can fluctuate. It is generally recognized that the level remains at one-third to half way up the glass satisfactory.
Before any oil is added, the system should be fully charged. This is especially important when the compressor is above the level of the evaporator. The oil level should be reviewed once the system has completed its initial pulldown, or worked for at least two hours. If the sight glass indicates foaming, make sure it's not the result of refrigerant absorbed. Systems that have this condition are likely to be equipped with crankcase heaters.
Oil can be added to the crankcase large compressors, just pumping down and reduce the pressure in the crankcase for oil to be poured out, when the filler cap has been removed. However, filler hole, usually small by some compressors and oil pump can be used.
Too much oil in the crankcase can lead to damage of the compressor through the creation of dynamic pressure at work.
The procedure for adding oil will obviously vary depending on the type of compressor.
Charging pump and easy filling
Oil pump injection is similar to the cycle of the pump and needs no explanation. The correct oil level should be achieved, and reference should be made to the manufacturer's data.
Sometimes it is enough to add oil to the compressor until she runs out of the hole to fill; the probe will be required for other types. In each case the oil level is such that it is about 25 mm (1 inch) below the crankshaft, bearings, or splashers immerse in the oil, rotation of the shaft (Fig. 110).
When the compressor has a sight glass, it is a simple task to add oil. The procedure is as follows (Fig. 111):
1. Turning off the pump in the system to reduce the pressure in the crankcase to 0.1 bar (1 psi) and front seat of both the suction and discharge valve.
2. Remove the oil filler plug and install the charging line, including valves and adapter to insert the filler hole.
3. Place the free end of the charging line in capacity with pure and uncontaminated oil from a sealed can. Crack off the intake valve from the front seat position and increasing the pressure in the crankcase to 0.1 bar.
Open the shut-off valve slowly and clean the charging line through the oil container. The front seat of the intake valve.
4. Connect vacuum pump to the sensor Union suction valve. 5 Switch on the vacuum pump and reduce the pressure in the crankcase slightly below atmospheric, that allows the oil to be drawn until the desired level is reached.
6. Stop the vacuum pump, crack off the intake valve from the front seat position, cleaning oil from charging line and close the shut-off valve. Then the front seat of the intake valve.
7. Remove the charging line and replace the oil plug.
8. Fully back seat and cracked off service valves, or install the operating position.
9 checking the tightness of the compressor.
10 Start the system and allow it to settle in average operating conditions. echeck oil level.
When charging the oil, make sure the charging line is always below the oil level in the container.
When the compressor design is such that the strainer and oil return into the Carter showed oil can be added through the intake valve pressure gauge Union the same way as described above, but use a pump to create a vacuum instead of a vacuum pump (Fig. 112).
Draining the oil in the compressor
This may be necessary when there is too much oil has been added, when the maintenance contracts allow for periodic oil change, or when the system has been contaminated.
Assuming that the compressor does not have oil drain installation and removal of base plate or plate clarifier or economically unreasonable, two simple methods that can be adopted.
This requires an airtight container or preferably a graduated cylinder so that the number of oil removed can be measured and the exact amount replace.
Pulling a vacuum container or cylinder, the oil will be removed from the compressor in the cylinder (Fig. 113). During this process, the compressor should be isolated from the system with the front seat of the service valve.
System pressure method
With a length of tubing and the adapter is equipped with a hole to fill after the pressure in the crankcase is reduced, and both valve front seated, creating a positive pressure in the crankcase the peel inlet valve from the front seat position (Fig. 114). Provided tube reaches the bottom of the crankcase or sump oil will be forced out of the compressor and the container.
Correcting the oil level
Pressure above method can be used to reduce the oil level in the crankcase in case of overload. By installing the adapter tube that ends at the right level below crankshaft oil will be forced out of the compressor crankcase pressure but only until the oil level reaches the end of the tube...