Lovato VLB30055A480 5.5 kW VLB3 Variable Speed Drive

VLB3 frequency inverter: 5.5 kW output from a three-phase mains

Variable speed from a three-phase supply is what the VLB30055A480 (VLB3 series, 5.5 kW (7.5 (Heavy load) / 10 (Standard load) HP), 13 A) provides; input 400-480VAC 50/60Hz, output 0-599 Hz. It lets a squirrel-cage motor accelerate and run at controlled speed.

Radio-frequency interference is handled by the built-in EMC suppressor cat. C2 inside the housing, and the serial port is RS485, Modbus-RTU.

Overload capacity is 150% for 60s; 200% for 3s, with a switching frequency of 2-16kHz.

Technical specifications

What to check for rating and control

Rated output is 13 A (5.5 kW); overload capacity is 150% for 60s; 200% for 3s. That is enough for typical pump and fan duty, while crushers and heavy starts should be checked against the overload figure and, if needed, a size up.

Control modes listed: V/f linear, quadratic torque, sensorless vector control, ECO mode, servo control with encoder feedback, multipoint V/f curve, V/f closed loop control with encoder feedback, torque setpoint, sensorless.

A brake chopper is built in and the safe-torque-off function is optional.

Typical duties and mounting

Typical uses are pumps and fans where a PID loop holds pressure or flow, conveyors and mixers, and small machine tools needing adjustable speed. Because the permitted motor cable length depends on the EMC category chosen, check the cable table in the datasheet when the motor is far from the panel.

Dimensions of 90 x 278 x 130 mm and a mass of 2.45 Kg make this a panel-friendly size. Protection is IP20, so place it in an enclosure suited to the environment and keep motor and control cables separated.

Commissioning the VLB3 on a pump or fan

Before power is applied, check that the supply is within the operating mains voltage range and that the motor is wired for the correct voltage in star or delta. Enter the motor nameplate values, then pick the control mode that suits the load: quadratic torque or ECO mode for centrifugal pumps and fans, and sensorless vector control where a conveyor or mixer needs good torque at low speed. Set acceleration and deceleration ramps that avoid water hammer in pipework and excessive belt slip on fans.

• For pressure or level control, wire the transmitter to one of the analogue inputs, set the input type, and tune the PID loop with small steps before relying on it for automatic operation.
• If the multi-pump function is used, confirm how the two auxiliary pumps will be started and protected outside the drive, since they run in direct mode.
• Configure the relay output for a run or fault signal so the plant control system knows the drive status.
• If Modbus-RTU is used, set the address, baud rate and parity to match the master, and terminate the RS485 line at both ends.

Troubleshooting and routine care

Record the drive parameters after commissioning so a replacement can be set up quickly. When a trip occurs, note the protection that acted before resetting: repeated overcurrent trips usually point to short ramps or a mechanical problem, while phase loss or undervoltage alarms lead back to the supply or its fuses. Keep the cooling path free of dust and check terminal tightness during planned stops.

Panel heat and dust in Oman and GCC sites

The datasheet already sets out the current derating above 45°C or 40°C depending on switching frequency, and summer panel temperatures in pump stations and rooftop plant rooms across the region often reach that zone. Choosing a lower switching frequency, adding panel ventilation or air conditioning, and shading outdoor cabinets all help keep the full 13 A available. Since the drive is IP20 and rated for pollution degree 2, install it in a sealed, filtered enclosure at dusty and coastal sites, and prevent condensation where humid sea air cools inside the panel at night.

Documents and quotation

The Lovato Electric datasheet for VLB30055A480 (English, exported from the manufacturer’s online catalogue) is attached and is the source of the figures above. Before ordering, confirm the motor nameplate current, the supply type and voltage, the EMC category needed for your cable lengths and whether a keypad or safe-torque-off option is required; datasheet values can be revised by the manufacturer. Other options are in ac drives. An RFQ for VLB30055A480 needs only the quantity and delivery location; Seven Star LLC, an independent Muscat supplier, replies with availability.