THINGS TO CHECK IF THE COMPRESSOR WILL NOT START BUT THE FAN RUNS:
High voltage wiring. Turn off the power to the unit and check all electrical wiring to the compressor. Check particularly for burned wires at the CONTACTOR, the RUN CAPACITOR, and inside the COMPRESSOR TERMINAL BOX on the side of the compressor. Check to see if the actual CONTACTS of the contactor are not damaged to the point they do not work. Make sure no insects have been trapped under the contacts and thus impeding the flow of current.
|Examine the contactor for unwanted object under the contacts or improper "making" (closing) of the contacts. The compressor may be getting voltage, but not the proper current.|
- Run capacitor. Examine the run capacitor or capacitors for "bulging" or for burned terminals or burned wires. If you suspect a problem with the capacitor, take it to an air conditioning contractor or supply house of air conditioning parts and ask them to check the INTERNAL capacitance of it.
- Stuck Compressor. You may have to replace the compressor or the condensing unit because of
this problem, but there are some attempts at repair to be made. By this, we mean that the motor or the pump inside the compressor
is bound and will not turn even with the correct amount of voltage and current supplied to it. There are several ways to possibly
remedy this and some are a more permanent repair than others, but most are only temporary fixes if the cause is binding of parts
internally or bad INTERNAL BEARINGS. Don't laugh at the solutions I give. They will possibly gain you a few days of warm heat pump
air or cool air conditioning:
- Start assist component. Add a capacitor, bleed resistor and start relay to the compressor if none are already on it. If these already are in place and it is working but will not start the compressor, then you might try changing the capacitance of it to a larger size. Notice the relay. Terminals 2 and 1 have a set of contacts that are closed until the coil of terminals 2 and 5 is energized and activated. This set of contacts will remain closed until voltage is applied to the coil of the relay AND the compressor gains enough speed. This is a second or less. While the contacts are closed and the voltage is applied, the capacitor is supplying another type of voltage to the compressor windings. This gives the compressor extra ability to start and run and it does so more quickly. Examine the start capacitor, if the unit has one, and look for a blown port or burned wires or loss of particles or fluid from it. You will need a capacitance checker to know if it is good otherwise and may need to take it to a service shop for testing. Take the relay as well. You can purchase a complete replacement kit for less than forty dollars if this is the solution. If you really want to know the working theory of these components, see start kits section.
- Thermistor controlled "boosters".
You might get by with one of the new thermistor controlled "boosters" if the compressor has no start assistance at present. Just push on the terminals for the booster onto the compressor's capacitor terminals as shown. They are good for "soft starts", but once energized will take several minutes to cool before they will work again.
- Overheated compressor. Don't mistake an overheated compressor for one that is stuck. If a compressor is overly hot it will trip an internal protector and when it cools down it will re-set itself. If you turn off the electricity to the unit, you can cool it until it re-sets with a fairly small amount of water from a hose. Be careful not to create an electrical hazard with the water. Standing in water will increase your chances of a fatal electrical shock many times over.
- Jolting it loose. If you could pick up the compressor and jostle it rudely, you might could get some of the internal parts of it to move just a bit and thus get off that impeded position it might be in, but this is unlikely that you can do this. The next best thing is a "shock treatment". Use a large sledge hammer and literally bang it briskly from a horizontal blow close to the top of the compressor. If this causes it to start working, it will fail again, but maybe not until you can get it replaced.
- Compressor oil. This is a less likely cause maybe, but maybe not.
When a unit freezes up the oil will be washed out of the compressor and rest in the tubing and cooling coil.
- One solution to this problem is to pack the compressor in ice for several hours and hope the migration of oil back to the compressor will be sufficient to lubricate it until it can recover enough the proper way while it runs normally. If you do this, you will need to leave the unit off, but with the power supply on for eight hours minimum after the ice is removed. This will let the compressor warming get the refrigerant back out of the compressor while allowing the oil to remain. This is a long-shot, but it may work if you have the time.
- You could temporarily PUMP SOME OIL into the compressor, but this is probably beyond your scope and will require a service technician. If you do get the compressor running, you can recover the stranded oil more quickly if you shut the DISCHARGE VALVE considerably, but not closed, for a period of minutes and it will cause the system to run "starved" and will draw the oil back with the aid of the very low SUCTION PRESSURE and the very high pressure in the condenser coils.