Protection of HVAC Building Heating and Cooling Systems Against Sudden Overvoltage

Protection of HVAC Building Heating and Cooling Systems from Sudden Overvoltages, HVAC equipment is critical for maintaining building environmental control, but power problems caused by the grid, sudden overvoltage impulses, or lightning impulses pose real threats to these systems. VFDs (Variable Frequency Drives) running chillers, cooling towers, air compressors, pump controllers, and other high-value devices are particularly sensitive to failures caused by electrical surges.

Safetec Iskra surge arrester

• VFDs control the speed of AC induction motors, and standard VFDs have six diodes connected to the input terminals that are sensitive to sudden voltages.
• The cumulative damage produced by sudden overvoltage impulses in diodes is irreversible and eventually causes the diodes to fail.
• This situation causes the breakdown of the input diode bridge, which stops the system. It is essential to ensure long life for critical VFDs and to protect these systems in places like hospitals, hotels, shopping malls, universities, etc.

Drive systems must be protected from sudden overvoltage impulses.

The repair cost includes not only hardware replacement costs but also the labor cost of maintenance crews. Labor costs vary from city to city, and the cost of expert technicians and travel expenses can range from 1000 to 4500 TL per breakdown.

You May Be Interested In: Type 1+2+3 LV Surge Arresters

So How Are HVAC Systems Protected?

When a lightning impulse comes, it prevents physical deformation primarily and then electrical faults by not transmitting the impulse to the system. Even if the lightning impulse strikes a very distant point, HVAC and pump systems, which are generally located on the ground floors of the building and utilize the building ground, can be directly exposed to the impulse. Therefore, they should be protected with Type 1+2+3 LV Surge Arrester systems to be selected according to the continuous voltage level, number of phases, and system feature in HVAC panels. If there are Type 1+2+3 protection products in the building main panel, Type 2 LV surge arrester systems with Safetec technology can be used in motor panels. For drive parts, the correct surge arrester should be selected according to the voltage they are fed. For 3-phase AC fed drives, products available up to 440 Volts can be used according to the voltage level again. Also, 24 V energy protection surge arresters can be used for the communication and PLC part.