This year’s summer has again been hot and some areas have experienced exceptionally heavy rainfall and high humidity. Consequently, enclosure air conditioners have had their work cut out keeping electrical enclosure temperatures and humidity under control. With cooler weather coming on, this is a good time to perform end-of–summer maintenance checks and make sure that everything is ready for winter.
Here are seven maintenance tips that will ensure that your air conditioners are in good condition and help you to identify anything that needs further attention.
1. Check Air Conditioner Operation
As a first step, check the current operation of the unit and make sure it’s cooling properly. It helps if you have records of the actual enclosure and ambient temperatures so that you can identify if the enclosure air conditioner is not performing as it should. Make sure the circulation fans are running and take note of any strange noises that may indicate worn bearings or other potential problems. In particular, listen for unusual mechanical noises emanating from the compressor and make sure it’s not too hot. Under normal conditions the compressor temperature should be such that it is just possible to touch the compressor. Ensure that all piping is properly secured. If the unit is fitted with a heater, make sure the heater cuts in. You may need to wait until a cool morning to do this because the heater will not normally cut in unless the enclosure temperature drops below 52°F. Alternatively, you can adjust the heater thermostat setting on the digital controller.
2. Check and Clean Filters
The air inlet filter for the condenser should be removed and checked. If blocked, it should be replaced. Alternatively, if it is washable, clean it using the correct filter treatment spray that is available either in an aerosol can or a spray bottle. If the filter is heavily soiled, it is possible that the dust load is too high and consideration should be given to installing a high-capacity filter that is designed for very dusty conditions.
3. Clean the Condenser Coil
Although the condenser coil is protected by the filter, some dirt will get past the filter and the coil should be cleaned. Care must be taken when cleaning the condenser coil not to puncture any pipes or flattening any cooling fins, so avoid using sharp implements or wire brushes. Compressed air and a small soft brush may be used if necessary. If using compressed air, wear protective goggles.
4. Check the Condensate Recovery System
Make sure that the condensate evaporation system is working properly. This can be confirmed by ensuring that the hot gas pipe is correctly positioned in the tray and that the water level is below the emergency overflow pipe. If there are signs of mold, empty the pan and treat it with a small quantity of diluted bleach. Ensure that the emergency overflow pipe is clear.
5. Inspect for Refrigerant Leaks
Although specialist equipment is needed to verify that the unit contains the correct amount of refrigerant, it is possible to check for refrigerant leaks. Refrigerant gas contains small amounts of lubricating oil from the compressor and, if there is a leak, there is usually an oil residue deposited in the area around the leak. If any leaks are found, do not attempt to repair the leak, but shut the unit down and call a refrigeration technician.
6. Verify Enclosure Sealing
Enclosure air conditioners operate on a closed loop cooling cycle, and it’s essential the electrical enclosure is properly sealed. Check that the enclosure doors close properly and that the door seals are in good condition. Also ensure that the air conditioner enclosure is securely attached to the electrical enclosure and that the sealing gasket is in good condition. Confirm there are no holes in the enclosure. Reasons for this could include the removal of redundant conduits and cables. If any holes are found, they should be sealed.
7. Seek Technical Assistance
If the enclosure air conditioner is not working properly or there are other indications that all is not well, contact a competent refrigeration technician or the Thermal Edge Support Team for advice and assistance.