2.3.3 Cooling system types for inverter enclosure From the enclosure that contains the inverter, the heat of the inverter and other equipment (transformers, lamps, resistors, etc.) and the incoming heat such as direct sunlight must be dissipated to keep the in-enclosure temperature lower than the permissible temperatures of the in-enclosure equipment including the inverter. The cooling systems are classified as follows in terms of the cooling calculation method.
• Cooling by natural heat dissipation from the enclosure surface (totally enclosed type) • Cooling by heat sink (aluminum fin, etc.) • Cooling by ventilation (forced ventilation type, pipe ventilation type) • Cooling by heat exchanger or cooler (heat pipe, cooler, etc.) 26 2. INSTALLATION AND WIRING 2.3 Installation of the inverter and enclosure design Cooling system Enclosure structure Comment Natural Natural ventilation (enclosed ventilated type) INV This system is low in cost and generally used, but the enclosure size increases as the inverter capacity increases. This system is for relatively small capacities.
Natural ventilation (totally enclosed type) INV Being a totally enclosed type, this system is the most appropriate for hostile environment having dust, dirt, oil mist, etc. The enclosure size increases depending on the inverter capacity. Forced air Heat sink cooling Heatsink INV This system has restrictions on the heat sink mounting position and area. This system is for relatively small capacities. Forced ventilation INV This system is for general indoor installation. This is appropriate for enclosure downsizing and cost reduction, and often used. Heat pipe Heat pipe INV This is a totally enclosed for enclosure downsizing.