Helios Fans KRD 355÷4÷60÷35

The Helios KRD 355÷4÷60÷35 is a rectangular centrifugal fan engineered for direct installation in rectangular duct systems. It features a backward curved impeller and a compact housing made of galvanized steel with flanged connections on both ends. The unit is designed with a swing-out motor and impeller assembly, enabling easy access for cleaning and servicing. Models from size 450 and up include an additional locking mechanism for the swing-out unit.

The fan is equipped with a high-performance centrifugal impeller constructed from impact-resistant polymer and galvanized steel, dynamically balanced to Class G 6.3 as per VDI 2060 and ISO 1940 standards. It operates with a totally enclosed, 3‑phase external rotor motor integrated with thermal protection and connected to an IP55 terminal box. The motor supports speed control via a 5‑step transformer, a stepless electronic controller, or a Helios frequency inverter with sinus filter on all poles. Maintenance-free, low-noise ball bearings with lifetime sealing and tropical protection of the windings ensure long-term, reliable operation.