175H7433 by Danfoss

The 175H7433 is an AC variable frequency drive manufactured by Danfoss within the VLT 3000 Variable Speed Drives series. The unit modulates the voltage-to-frequency ratio delivered to a three-phase induction motor, allowing precise speed regulation and energy matching in conveyor, pump, and fan applications. By providing controlled acceleration, deceleration, and overload handling, the drive supports continuous-duty industrial automation tasks while helping protect mechanical components and reduce electrical stress.

During constant-torque operation, the drive can supply a motor with 15 HP of mechanical power. Its inverter section sustains a continuous output of 24.0 A, while a timed overload envelope permits 38.4 A for up to 60 seconds to accommodate high starting inertia. The synthesized output frequency is adjustable from zero up to 500 Hz, enabling both overspeed and very low-speed control without cogging. Electrical installation requires a line fuse or molded-case breaker rated no higher than 63 A, and the input side may draw as much as 21.8 A under worst-case loading. When fully loaded, the conversion efficiency reaches 96%, which helps limit waste heat and reduce cabinet ventilation demand. These values set the electrical and thermal limits for the surrounding automation cabinet.

In centrifugal pump or fan duty, the quadratic-torque profile allows delivery of 20 HP while lowering current draw as speed falls to improve part-load performance. Under constant-torque conditions, the output apparent power is 17.3 kVA, rising to 23.0 kVA when variable torque is selected, which helps with transformer capacity checks. The inverter dissipates only 425 W at maximum load, so internal temperatures remain controlled during extended cycles. A programmable acceleration or deceleration ramp up to 3600 s can reduce hydraulic shock and mechanical resonance, and an integrated RFI filter simplifies EMC compliance without external modules.