A variety of factors can cause the failure of the air conditioner compressor to start or switch on.
Some may be easier to fix than others. Still, the reality is that we must pay attention when these types of failures occur because we must examine both electrical and mechanical components to determine the root reason why the air conditioner compressor won’t turn on.
It’s incredibly likely that something is wrong with the compressor or that some of its electrical components have failed and need to be replaced.
Let us keep in mind that the usable life of any electrical gadget decreases over time. Also, it falls on you to maintain your air conditioner. For that, you must know how to clean a split AC, and how to clean a window AC, depending on which appliance you have.
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Why AC compressor not starting?
When an air conditioning compressor fails to start, it can be due to a variety of factors, including:
- Mechanical failures
- Electrical failures
- Electronic failures
AC compressor does not start due to mechanical failure
The air conditioner compressor is one of the most important components of an AC unit, and it needs to be in good working order for the unit to function properly. Unfortunately, compressors can sometimes fail due to mechanical issues. If the compressor does not start, the AC unit will not be able to cool the air properly. In some cases, the compressor may need to be replaced.
1. Compressor with damaged coil
High voltages, age, and high temperatures inside the compressor can all cause damage to the coils. The electrical coils will not work correctly as a result, and the air conditioner will not start or switch on.
When the air conditioning compressor cannot start due to faulty electrical coils, it will occasionally do nothing or even attempt to start. To determine whether a compressor is in good working order, the technician must be able to measure the electrical coils.
It’s bad news when a compressor’s coils are destroyed since the compressor must be replaced.
2. Locked Rotor Compressor
This is a typical compressor defect discovered when the compressor’s initial Amperage exceeds its intended limits. Amperage is on the marking plate of every compressor, often known as LRA.
A regular starting amperage consumption must be between the amperage values brought by the compressor plate. If this initial Amperage is between those reference values, the compressor is performing correctly.
When the compressor tries to start but cannot do so because it is jammed or clogged, more Amperage is consumed than is necessary, even considerably more than the starting amperage (LRA) for which it was designed.
The main causes of blockage in compressors are:
- An old compressor with a long life of use can cause wear.
- The air conditioner has an excess charge of refrigerant gas
- High pressure in the condenser due to lack of maintenance, fan stopped, etc.
Any of these problems can raise the temperature and pressure due to lack of ventilation. The solution is to check the cause of the lack of ventilation. When there is a refrigerant gas leak, the oil inside the compressor is also lost, which is responsible for lubricating its parts.
3. Damage to the compressor itself
The compressor itself could be faulty. However, this is usually not the case.
Before replacing the compressor, check the most commonly failed components, particularly the compressor’s overload protector and capacitor.
The compressor protects itself from overheating. When the air conditioner does not start due to a lack of ventilation in the external unit, the thermal protector opens to turn off the compressor, avoiding permanent damage since it increases pressure, amperage, and temperature.
Air conditioner won’t start due to electrical failure
Many air conditioners use electricity to operate, so it’s not surprising that electrical problems are a common cause of AC failures. If your unit won’t start, the first thing you should check is the power supply. Make sure that the unit is plugged into a working outlet and that the circuit breaker hasn’t tripped. If you’re not comfortable troubleshooting electrical problems, it’s best to call a qualified technician. With a little investigation, most electrical issues can be quickly resolved, and your air conditioner will be up and running again in no time.
1. Problems with low voltage
To measure the voltage in an air conditioning unit, a multimeter can be used. By doing this, you will obtain accurate measurement of the voltage that reaches the equipment.
There are a few things that can cause low voltage, including loose connections, damaged wiring, or a problem with the power supply.
To fix this problem, first check all the connections to make sure they are tight. Next, check the wiring for any damage. If you find any damage, you will need to replace the damaged section of wire. Finally, check the power supply to make sure it is providing enough power to the air conditioner. If the power supply is not working properly, you will need to replace it.
2. Damaged fan and compressor capacitors
The function of a capacitor in the compressor and in the fan is to help maintain a constant working speed. The capacitor is connected to the compressor by means of electrical cables. If the capacitor burns out, the compressor will not work. To find out if the capacitor is damaged, use a tester to test its value in microfarads. If it is bad, replace it.
If the capacitor of the fan is damaged, the fan will start to rotate slower than normal. If the fan does not work properly the compressor will overheat and shut down due to thermal protector protection.
In either case the capacitor must be replaced.
3. Overheated and broken terminals
Cables and connections are the ones that suffer the most from high voltages and overheating. Over time, the connections wear out, which can cause the air conditioner to not start or turn on.
The solution to this problem is to visually inspect all the wiring of the equipment and detect which cables are damaged in order to replace them.
4. Damaged thermal protector
The thermal protector has two stages of operation – to supply voltage to the compressor and to protect the compressor from overheating and high amperage.
If it is damaged, the compressor will not receive the correct amount of power. As a result, the air conditioner will not be able to start up.
If you suspect that your air conditioner’s thermal protector is damaged, you should take it to a qualified technician for repair. In the meantime, you can try to start the air conditioner by resetting the circuit breaker. If this does not work, you may need to replace the thermal protector.
5. Damaged thermostat
The temperature control thermostat has electrical connections inside it that can burn out over time. If the air conditioner is a window unit and the air conditioner does not start, it may be because the thermostat has been damaged.
If the thermostat is damaged, it will need to be replaced. The first thing to do is check the power supply to the air conditioner. Make sure that the circuit breaker is turned on and that there is power to the unit. Next, check the wiring to the thermostat. If the wiring is loose or damaged, it will need to be repaired or replaced. Finally, check the thermostat itself. If it is cracked or broken, it will need to be replaced.
Air conditioning does not start due to electronic failure
Electronic controls are responsible for telling the air conditioner when to turn on and off, as well as regulating the temperature. If these controls fail, the air conditioner will not be able to operate properly. Most electronic failures require the intervention of trained technicians
1. The PCB is damaged
A PCB in AC is a Printed Circuit Board. It is a board that is used to connect electronic components together. The PCB allows for electrical signals to flow between the different components that are connected to it.
If the PCB is damaged, it can cause the electronic components to stop working properly and prevent the compressor from turning on.
If the PCB is damaged, it can often be repaired. This is because the PCB is made of conductive material that can be soldered. If a trace on the PCB is damaged, it can often be repaired by soldering a jumper wire to bypass the damaged trace. However, if the damage is severe, the PCB may need to be replaced.
2. Damaged contact and well thermistors
The thermistor is a sensor connected to the control board that detects the outside air temperature. It is made of semiconductor material. The resistance of thermistor increases with the increase of temperature. The contact between the two leads of thermistor can be damaged due to overheating. This will cause the air conditioner to malfunction.
If the thermistor does not have continuity, it prevents the compressor or equipment from turning on. To determine if the thermistor is failing, use a multimeter to test its continuity. If the thermistor has no continuity, replace it.
3. Air conditioning transformer and relay
The relay board provides voltage to many of the air conditioning components. If the board is faulty, it may stop sending voltage to the compressor.
Before replacing the board, be sure to check the most commonly faulty parts, in particular the overload protector (Fuses), the compressor capacitor, and the compressor itself.
The transformer is responsible for powering the electronic card, when it is damaged the electronic card is left without electricity, that is, it is out of operation.
To know if the transformer is working well, you must use an ammeter and measure that the output of the transformer has the voltage output that the equipment needs.
What are the signs and symptoms of a bad AC compressor
If your AC compressor is going bad, you’ll likely notice some of the following signs and symptoms:
- Your air conditioner is making strange noises. A healthy compressor should run quietly, so if you start to hear loud, unusual sounds coming from your unit, it’s a sign that something is wrong.
- Your air conditioner is leaking refrigerant. If you see any type of refrigerant leak, it’s a sure sign that your compressor is going bad and needs to be repaired or replaced.
- Your air conditioner is not cooling your home as well as it used to. If you’ve noticed that your air conditioner isn’t cooling your home as efficiently as it used to, it could be a sign that your compressor is on its way out.
- Your air conditioner’s cycle times are longer than normal. If it’s taking your air conditioner longer to cycle on and off, it could be a sign that the compressor is struggling to do its job.
If you notice any of these signs or symptoms, it’s important to call a qualified HVAC technician right away. They will be able to diagnose the problem and recommend the best course of action. In some cases, a bad compressor can be repaired, but in other cases, it will need to be replaced.
When the air conditioner compressor won’t turn on, the first thing you should do is check if there’s power going to the unit. If there is, then the problem may be with the compressor itself or with one of the components connected to it. In some cases, the compressor can be repaired, but in other cases, it will need to be replaced.
If you notice any strange noises coming from your unit, refrigerant leaks, or if your air conditioner isn’t cooling your home as well as it used to, call a qualified HVAC technician right away. They will be able to diagnose the problem and recommend the best course of action.
Frequently Asked Questions (FAQs):
1. How do I get my AC compressor to kick on?
There are a few things that could be preventing your AC compressor from kicking on. First, check to make sure that the unit is properly plugged in and receiving power. Next, check the thermostat to make sure it is set to cooling mode. Finally, check for any loose wires or debris that may be blocking the unit. If you still cannot get the unit to turn on, you may need to call a professional for assistance.
2. How do you reset an AC compressor?
There are a few ways that you can reset an AC compressor. One way is to simply turn the power off to the unit for a few minutes, then turn it back on. This will usually cause the compressor to reset itself. Another way is to unplug the unit from the wall outlet, then plug it back in. This will also usually cause the compressor to reset itself. Finally, if neither of these methods work, you can always consult your owners manual for specific instructions on how to reset your particular model of AC compressor.
3. How do I test my AC compressor?
If your AC compressor is not working properly, it can be tested for a number of different issues. To test your AC compressor, you will need a voltmeter, an ammeter, and a multimeter. First, use the voltmeter to check the voltage at the compressor’s terminals. If the voltage is too low, the compressor may not be getting enough power. Next, use the ammeter to check the current draw of the compressor. If the current draw is too high, the compressor may be overloaded. Finally, use the multimeter to check the resistance of the compressor’s windings. If the resistance is too high, the compressor may be overheated.
4. How long does it take an AC compressor to reset?
It typically takes about 30 minutes for an AC compressor to reset. However, this can vary depending on the make and model of the compressor. If your compressor has a built-in reset button, you may be able to shorten the reset time. Always consult your owner’s manual for specific instructions on resetting your particular model of AC compressor.
5. Why is my outside unit not turning on?
There are a few reasons why your outside unit may not be turning on. One possibility is that the power to the unit has been shut off. Another possibility is that the thermostat may not be set properly. Finally, it is also possible that there is a problem with the unit itself. Check whether the unit is receiving power or not. See the wiring to see if there are any loose connections. If you have checked all of these things and the unit still does not turn on, you should contact a qualified technician to help diagnose and repair the problem.
6. What causes an AC compressor to lock up?
One of the main reasons an AC compressor can lock up is because of low refrigerant levels. If there isn’t enough refrigerant in the system, it can cause the compressor to overheat and eventually lock up. Other potential causes include a dirty or restricted filter, a faulty pressure switch, or a problem with the electrical system. In some cases, a locked up compressor can be repaired by simply adding more refrigerant or fixing the underlying issue. However, in other cases, the compressor will need to be replaced.
7. How long does it take for an AC compressor to turn on?
It typically takes around 3-5 minutes for an AC compressor to turn on. However, this can vary depending on the specific make and model of the compressor. If you notice that your compressor is taking longer than usual to turn on, it may be a sign that it needs to be replaced.
8. What is the most common cause of compressor failure?
The most common cause of compressor failure is overheating. When a compressor overheats, it can cause the oil to break down, which can lead to increased wear and tear on the internals of the compressor. Additionally, an overheated compressor can cause the seals to fail, which can allow refrigerant to escape and potentially damage other components in the system.
9. How do I know if my AC compressor has power?
There are a few ways to tell if your AC compressor has power. One is to check the fuses or circuit breakers. Another is to look for a light on the control panel that indicates power is present. Finally, you can try turning on the unit and feeling for air coming out of the vents. If none of these methods work, it’s possible that the compressor itself is not getting power. In this case, you’ll need to contact a qualified technician for further diagnosis.
10. How do you tell if a compressor is burnt out?
If your compressor is burnt out, it will usually show signs of wear and tear. The most common sign is a loss of power. Your compressor may also produce strange noises or smells, and it may overheat. If you suspect that your compressor is burnt out, take it to a professional for inspection.