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Electrical Preventive Maintenance Can Prevent Many HVAC Problems

Many conscientious building owners follow a prescribed HVAC preventive maintenance program to a “T”, performing monthly and quarterly PM activities on a regular basis. Electrical preventative maintenance, however, is overlooked all too often.


With 78-80% of HVAC failure relating to electrical issues, it is wise to incorporate electrical PM with HVAC preventive maintenance. UPS systems and standby backup generators that serve critical equipment are often the culprit when problems occur. UPS batteries fail or don’t recharge properly, leaving HVAC systems unprotected and without uninterrupted power when needed most. Generators need to be exercised weekly and have their batteries tested and replaced as required. Starters and contactors should be checked for wear and possible arcing on the contactors. Motors 20 HP and require vibration testing on a yearly basis and should be megger tested to determine the condition of their windings. VFDs should be checked for accumulated dust and dirt and cleaned when necessary. Using a thermal camera to check for hotspots in motors, compressors and breakers can ward off much bigger problems.


Case in point: one afternoon last summer, MSC received an emergency service call from a New Jersey university. A major charity event was scheduled for that evening, but the cooling system was not working and temperatures were starting to rise. It turned out that the uninterruptible power supply had failed to kick in when a momentary electrical blip occurred earlier in the day. The UPS hadn’t been maintained, and the batteries were dead. This caused the I/O to an important control panel to shut off, which in turn shut down pumps, which then caused chillers to shut down, leaving the building without cooling. MSC was able to get the pump VFDs operational to establish flow and reset the chillers in time for the evening’s event, and a new local UPS system was ordered and installed the following week.