When troubleshooting any refrigeration or air conditioning system in Palma de Mallorca, its important to have a good understanding of how the system works. It doesn’t matter if its on a superyacht, commercial hotel or domestic house or apartment. These are a great place to start your diagnosis.
Initial checks for any air conditioning unit should always include the following:
Firstly, lets start with the basics.
1. Are the filters on the indoor unit clean?
All indoor (Evaporator) units should have a filter installed to prevent the cooling coil from becoming blocked or dirty. This is definitely the first thing to check, as it is easily cleaned and can greatly affect the performance of the unit. It will reduce the amount of airflow across the coil
2. Is the coil on the outdoor air cooled condenser clean?
This is also very common. Especially when located in a dusty environment. Simply switch the power off to the unit and brush it down with a soft bristled brush. Take care not to damage the aluminium fins on the coils, as this can then reduce the airflow through the condenser. You can also wash it down with a hose and water but take care to keep the water away from any electrical components. Some indicators that a dirty condenser could be the problem, would be a hot (to touch) liquid line and also the compressor.
3. Is the fan running on the outdoor unit? The fan is used to help reject the heat out of the system via the condenser. If this isn’t running then the heat will stay in the refrigerant and reduce the efficiency. It also raised the pressure of the refrigerant and can cause it to trip out on the high pressure safety switch.
4. Is the suction line cold and sweating? Sweat on the suction line is a good indication that the system is working correctly. It tells us that the evaporator is cooling efficiently and that there is sufficient cooling coming back to the compressor.
5. If the unit has a sight glass is it bubbling?
Bubbling in the sight glass can be caused by a number of things so don’t just assume it is short of refrigerant (although this is the most common cause). The problem with bubbles in the sight glass is that it means there is a two-phase mix (liquid and gas) at the inlet of the expansion valve. This will cause the expansion valve to freeze up and also starve the evaporator of refrigerant.
6. Is the fan running on the indoor unit? If the indoor fan fails, then less heat will be absorbed by the evaporator and the suction pressure will fall. This can cause the system to trip on low pressure but more importantly it runs the risk of liquid refrigerant coming back to the compressor and causing damage.
7. Is the unit running? Check power to the unit. Is the circuit breaker tripped? It might seem obvious but always worth a quick check.
8. Is the liquid line solenoid valve energised? If the system has a solenoid valve, then its worth checking that its working correctly. Common problems include:
• Valve is stuck in the closed position.
• Coil is burnt out
• Wrong voltage coil ie a 240V coil has been used on a 24V supply
• No signal to open – check thermostat or other source of supply.
9. Is the system Overcharged?
A system with too much refrigerant can cause serious issues. To start with the pressures become too high and there is also a risk of liquid refrigerant causing damage to the compressor. It also increases the amount of current drawn from the compressor and if this goes above the maximum rated current of the compressor then it can eventually burn out.
10. Is the system short of refrigerant?
Shortage of refrigerant is either caused by poor commissioning or that the system has a leak and it has been released into the atmosphere. Whenever a shortage of refrigerant is found then you must suspect there has been a leak. And this means removing the remaining refrigerant, pressure testing and repairing the leak before evacuating and recharging the system. It is illegal to ‘Top the system up’.
11. Blocked liquid line drier
– If the filter becomes blocked, it reduces the amount of refrigerant that can reach the expansion valve and subsequently starves the evaporator, resulting in poor cooling capacity. Look for temperature different across the filter.
12. Are the safety devices tripped
Check the following:
• High pressure safety tripped – Overcharged, non-condensables in refrigerant, condenser blocked, condenser fan failure
• Low pressure safety tripped – Short of refrigerant, filter drier blocked, faulty or blocked expansion device
• Oil pressure switch tripped – low oil level, low oil pressure, high suction pressure, faulty oil pressure switch
• Compressor and fan overloads tripped – electrical fault, failed or siezed bearings
A lot of these faults can be prevented by simple and regular service and maintenance visits. If you would like Tradewinds to look after your refrigeration and air conditioning equipment then please don’t hesitate to give us a call.