Rooftop BESS Chiller (40 kW / 40+30 kW)

Both sides of the unit are intake grilles and the top carries axial fans — 7 on the 40 kW model, 12 on the 40+30 kW model. Air is drawn in at the sides, passes the condensers and is blown upward by the fans. On the roof, keep the space in front of both intakes open rather than against a sun canopy, cable tray or neighbouring equipment; where enclosures stand side by side, set their spacing for intake air and service access together. Fan guards and side grilles are blown clean with compressed air every two months.

The unit occupies 2506 × 1842 mm and weighs about 700 kg; on the 40 kW outline drawing, 20 Φ10 slotted holes fix the base to the mounting surface. On a 20 ft BESS enclosure it sits within the roof outline with room left around it for cabling and service. At the enclosure design stage ETENZ lays out the roof mounting beams from the unit weight and hole pattern, and issues the roof-to-beam connections, penetration positions and watertight seals on the same drawings, so the chiller can be installed and tested with the enclosure in the factory.

All connections are at one end. The 40 kW model has one Φ64 quick-clamp coupling each for supply and return, plus a CQC14 fill port; the 40+30 kW model has Φ64 on the battery side and Φ50.5 on the PCS side. The external junction box holds three terminal groups: three-phase 380 V power in, a commissioning output and an RS485 communication output. The dual-loop model draws 38 A at full load and is protected by a 50 A four-pole circuit breaker, fed through 10 mm² single-core power cable with an earth conductor of the same size. The enclosure's auxiliary distribution reserves this circuit, and the pipework enters at the roof penetration to reach the battery-rack manifolds and the PCS cooling connections.

Control is on supply temperature: the battery side defaults to 18 °C, can be set between 15 and 35 °C and is held within ±1 °C. In normal operation the unit follows BMS commands and switches to local automatic control if communication is lost. With a cooling demand the compressor and pump run; with a heating demand the pump and electric heater run, delivering 12 kW of heat; with neither, or on a BMS self-circulation command, the pump keeps turning at low speed. Cooling takes priority over heating, the two never run together, and switching is time-delayed. On the 40+30 kW model the 8 L reservoir starts topping up when return pressure falls below 0.3 bar and stops when pressure recovers to 0.8 bar or the reservoir level runs low.

Same footprint as the dual-loop model, 269 mm tall and with one coolant loop — the fit for enclosures whose PCS is air-cooled and where only the batteries need liquid cooling. At 45 °C ambient it supplies 18 °C coolant for 40 kW of cooling, with more than 240 L/min of flow, more than 20 m of external head and a cooling COP above 1.8. Electrical components are rated IP56 and the corrosion class is C4-⁠M; above 2000 m capacity is derated by 3% for every further 1000 m, up to 4000 m.