Lovato ADXT0034 34 A Soft Starter

A 34 A soft starter with built-in bypass

ADXT0034 is a 34 A soft starter from the Lovato Electric ADXT range. The built-in bypass relay carries the running current after the ramp, which keeps the thyristors cool; the power circuit is for 380-690VAC, and a control supply of 110-120VAC / 220-240VAC is required.

The ADXT0034 controls 3 phases of the motor circuit and limits the inrush through constant current, current ramp, voltage ramp, adaptive control. In the catalogue it is rated 34 A, which Lovato translates into 18.5 kW at 400 V in line and 22 kW at 400 V when connected inside the delta of the motor winding.

Technical specifications

Choosing the right rating

Pick the starter from the motor nameplate current rather than the kilowatt figure: 34 A is the rated starter current Ie, and the motor full-load current in your duty (standard or heavy) should not exceed it. The in-line IEC rating of 18.5 kW applies at 400 V and 40 degC.

Order-code reading, derived from the catalogue entry: the characters after ADXT give the current size (34 A for this code), with the standard auxiliary-supply version covering 110-120VAC / 220-240VAC.

Where it is used and how it is installed

The usual homes for a starter like this are pump stations, cooling-tower fans and material-handling lines. The ramp functions listed in the table let you tune acceleration and deceleration separately, which is useful where pipework or conveyed product is sensitive to sudden changes.

Installation is by screw-fixing. At 4.8 Kg and 152x336x233 mm the unit fits a normal panel; the protection degree is IP20, so it needs an enclosure where dust or moisture are present.

Key features of the ADXT0034

• Three-phase control: all three phases are controlled, which gives a balanced start compared with two-phase controlled starters.
• Inside-delta capability: connected inside the motor delta, the same 34 A unit covers 22 kW at 400 V instead of 18.5 kW in line.
• Four start methods: constant current, current ramp, voltage ramp and adaptive control.
• Five stop methods: including adaptive control and DC braking, useful for pumps and high-inertia loads.
• Comprehensive protection: motor, supply and starter protection functions plus a PTC thermistor input.
• Graphic LCD: menu-driven setup in 6 languages.

In-line or inside-delta connection

In the in-line connection the soft starter is placed in the three supply lines to the motor and carries the full line current. In the inside-delta connection it is placed in series with each motor winding inside the delta, so it carries only the phase current, which is about 58 percent of the line current. This is why the same unit is rated for a larger motor inside delta. Inside-delta wiring requires a motor with six accessible terminals and a line contactor, and is typically used to replace existing star-delta starters where the six motor cables are already installed.

Using the adaptive control

For centrifugal pumps, adaptive control shapes the acceleration and deceleration to the load, which helps reduce pressure surges and water hammer when the pump stops. For fans with high inertia, constant current starting limits the inrush while allowing enough time to reach speed; the starting-too-long protection should then be set to suit the real acceleration time.

Operation in GCC heat

The ADXT is rated up to +60°C with current derating above 40°C, and the built-in bypass keeps running losses low. In Omani pump stations and outdoor kiosks where panel temperatures exceed 40°C, check the derating in the manual before using the full 34 A. The IP20 enclosure must be installed in a dust-protected panel. The thermistor input is useful for motors exposed to high ambient or poor cooling, because it measures the winding temperature directly.

Documents and quotation

Attached is the English datasheet that Lovato Electric’s online catalogue generates for ADXT0034; the specification table above reproduces its values. Ordering checklist: the motor nameplate current and starting duty, the main supply voltage, the auxiliary control voltage and the ambient temperature at the panel. Data in the datasheet is subject to change by the manufacturer. See motor soft starters for similar items. Quote request: give the exact code ADXT0034, the quantity and where it must be delivered, and Seven Star LLC (independent supplier, Muscat) will respond.