Electric motor 280 kW, 740 rpm, 400 V / 690 V, H17RL 355X2-8 LV

Load fluctuations, long starts and the demands of continuous operation can quickly reveal a weak point in pump and fan assemblies. The H17RL 355X2-8 with an output of 280 is therefore designed to support efficient operation of a low-voltage drive in the 700-750 rpm segment and to provide a stable reserve for tasks where not only running, but also operational discipline and energy balance are monitored. In practice, this is a low-voltage asynchronous electric motor intended for environments where reliable starting, long-term load and sensible energy costs per energy consumer over the entire production cycle matter.

How the 700-750 rpm segment helps keep the drive in stable operation

In the 700-750 rpm speed segment, the motor operates at a rated speed of 740 rpm, which is suitable for technological assemblies with higher inertia and a need for smooth run-up. The rated torque of 3614 Nm provides a reserve during starting and when transitioning between operating states, while the starting torque ratio of 120 % and the breakdown torque ratio of 200 % help in applications where transient peaks appear on the shaft. The starting current ratio of 650 % must be taken into account when designing the power supply, especially if the operation works with limited network reserve or with frequent starting of large units.

The electrical design assumes a rated current of 533 A in a delta 400V connection and a current of 309 A in a star 690V connection. This combination makes it easier to size switchboards, protection devices and cable runs in plants where a 400 V / 690 V electric motor meets different levels of distribution infrastructure. An efficiency of 95.1 % and a power factor of 0.8 support the decisions of operators who monitor every kilowatt hour and need to keep losses under control during long-term operation. For tasks where energy-saving electric motors are compared, such a balance of output and operational discipline is important from the very first drive design.

A compact high-power solution for technical teams

A compact high-power solution is, in this model, supported by a frame size of 355 mm, which makes it possible to use space in the plant room without unnecessarily oversizing the assembly. The centre height in this class helps with integration into both new and modernised lines, where power density is monitored in relation to installation possibilities. The H17RL Compact PRO is also an 8-pole electric motor, which gives the operation a logical basis for technologies with higher torque demand and lower shaft speeds.

The modern design created using Hi-TECH technologies is reflected in a construction that supports long-term stability in operation with higher thermal and mechanical loads. Insulation class F together with temperature rise B create a suitable framework for longer duty cycles, where both the thermal reserve of the winding and the ambient conditions are monitored. The rotor cage is designed as a solid aluminium cage, which helps with robust torque transmission in demanding applications and during repeated load changes.

Choice of mounting design for industrial assemblies with limited space

The choice of mounting design is key in modernisations, where the original assembly is changed without intervening in the entire technological unit. The construction supports the available IM B3, B35, B5 and V1 versions, so the technician can adapt the installation according to the shaft position, flange type or mounting requirement. In conjunction with a weight of 2750 kg and an external starting inertia of 369 kg·m², this is a solution that must be correctly included in both the static and dynamic drive design.

The moment of inertia GD² 36,4 kg·m² is relevant when assessing starting behaviour and when choosing starting elements. For operations with pumps, fans, compressors and large machines, it is important that the motor behaves predictably even under variable load and that the assembly does not require unnecessarily frequent service interventions. VYBO Electric uses its own research and development in this segment, which is reflected in how the individual design details are aligned with long-term operational load.

Construction that supports long operation in harsh conditions

Electric motors in this class belong to the Heavy Duty process performance category and are intended for heavy industry, where the drive is expected to deliver long life, repeatable starting and a stable load profile. Standard equipment includes a cooling cover made of steel, reinforced bearing mounting including steel shielding and high-temperature grease, a terminal box in a metal design and reinforced bearing end shields for a more stable construction. Bearing DE 6322C3 and bearing NDE 6222C3 complement this design with a solution suitable for long service intervals and controlled operation at higher load.

In applications with a variable profile, sensitive monitoring of the condition of the winding and bearings also proves effective, because these are the points that determine premature wear in demanding operation. With the correct design of the connection and protection logic, the motor can be used in dewatering pumps, cooling fans, process fan units, screw compressors, blowers, mixers, high-inertia conveyors, rolling drives, extruders, crushers, briquetting presses and heavy machine units. Such deployment corresponds to the way operations plan long-term availability and the minimisation of unplanned downtime.

VYBO Electric, a verified manufacturer and distributor, provides technical advice for this series, helping to match the motor selection to the real operating conditions. If you need to fine-tune the sizing for a specific start, load or network conditions, please request a quotation.