The Rittal roof-mounted cooling unit SK 3387540 is an industrial-grade climate control device designed for mounting on enclosures or similar housings. It is used to cool electronic and electrical components in enclosed control panels, ensuring a constant operating temperature and extending the service life of the equipment. The unit is constructed from sheet steel and finished in RAL 7035, enabling robust and visually uniform integration into industrial environments. The roof-mounted design allows for easy installation on the top of the enclosure, with air intake and exhaust occurring through the upper section.

Applications
This cooling unit is designed for use in industrial environments, particularly in enclosures used in production facilities, automation systems, or power supply technology. Due to its low noise level, it can also be used in office applications where quiet operation is required. The operating temperature range of +10 °C to +55 °C and the storage temperature range of -40 °C to +70 °C make the unit suitable for a wide range of environments, including outdoor areas with varying weather conditions.

Features and Equipment in Detail
The unit includes an integrated e-Comfort controller, factory-set to +35 °C, which automatically regulates the temperature inside the enclosure. The adjustable range is between +20 °C and +55 °C, allowing the cooling capacity to be adapted to specific requirements. The integrated electric condensate evaporation system ensures that any condensate formed is automatically evaporated, reducing maintenance needs. The condenser is coated with a hydrophobic RiNano coating, which reduces moisture and dirt accumulation and improves heat transfer. The unit is pre-wired with a plug-in terminal block, simplifying installation. The package also includes a drilling template and mounting hardware to facilitate installation.

Technology Explained Simply
The cooling capacity is 3.8 kW at 50 Hz and L35 L35 operation, and 4.0 kW at 60 Hz. The rated power (Pel) is 1.7 kW (50 Hz) or 2.03 kW (60 Hz). Energy efficiency is described by the Energy Efficiency Ratio (EER), which is 2.24 at 50 Hz and 1.97 at 60 Hz. This means the unit produces 2.24 or 1.97 kWh of cooling per kWh of electrical energy consumed. The airflow rate is 3,870 m³/h in the outdoor circuit and 1,420 m³/h in the indoor circuit, ensuring efficient air circulation within the enclosure. The unit operates with refrigerant R-513A, which has a quantity of 1.8 kg and a Global Warming Potential (GWP) of 631. The maximum operating pressure is 28 bar, ensuring safety under high pressure loads. The duty cycle is 100 %, meaning the unit can operate continuously.

Compatibility and Accessories
The cooling unit is compatible with the SK-Bus system, allowing it to be networked with other devices. For connectivity with an IoT interface, the Blue e IoT adapter is available, enabling remote monitoring and control. Compatible accessories include, among others, the SK Controller (controller board for SK3387540), a condensate hose (12 x 2 mm, 10 m), a quick-change frame for Rittal TopTherm roof units, a door position switch, caps for the indoor air outlet, an air duct system, metal and filter mats, and lifting eyes for freight shipping.

Installation and Mounting
Mounting is done on the top of the enclosure. The drilling template and mounting hardware included in the package simplify installation. Electrical connection is made via a plug-in terminal block, enabling a secure and quick connection. The rated operating voltage is 400 V, 3~, 50 Hz or 460 V, 3~, 60 Hz. The maximum rated current is 4.1 A (50 Hz) or 4.5 A (60 Hz), with a maximum inrush current of 17 A (50 Hz) or 19 A (60 Hz). A fuse in the form of a motor protection switch rated 6.3 to 10 A is provided.

Operational Advantages
The unit offers high cooling capacity with good energy efficiency. The integrated condensate evaporation and hydrophobic RiNano coating reduce maintenance requirements. The factory-set e-Comfort controller at +35 °C ensures reliable temperature control. Compatibility with the SK-Bus system and IoT interface enables intelligent monitoring and control. The robust construction from sheet steel and protection ratings of IP 34 (outdoor circuit) and IP 54 (indoor circuit) ensure safe operation in industrial environments. Dimensions are 796 mm (width) × 470 mm (height) × 580 mm (depth), allowing for compact installation.