Lovato ADXT0084 84 A Soft Starter

Soft-start and soft-stop up to 84 A without a separate bypass contactor

The ADXT0084 is an ADXT-series electronic soft starter from Lovato Electric, rated 84 A and intended for standard and heavy-duty applications. A bypass relay is built in, so the thyristors only carry the motor current during ramp-up and ramp-down; once the motor is at full speed the bypass takes over and heat in the panel drops. The starter is supplied for a three-phase network of 380-690VAC and needs a separate control supply of 110-120VAC / 220-240VAC.

The ADXT0084 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 84 A, which Lovato translates into 45 kW at 400 V in line and 55 kW at 400 V when connected inside the delta of the motor winding.

Technical specifications

Sizing the starter for your motor

Because the rated starter current is 84 A, heavy-duty starts with long ramp times may need the next size up; the datasheet gives the IEC ratings (for example 45 kW at 400 V) for 40 degC ambient and states a derating factor beyond that.

Order-code reading, derived from the catalogue entry: the characters after ADXT give the current size (84 A for this code), with the standard auxiliary-supply version covering 110-120VAC / 220-240VAC.

Applications and installation notes

In practice this class of starter is chosen for booster pumps, ventilation fans, crushers and belt conveyors. A soft stop reduces water hammer in pumped lines, and the kick-start function helps loads that need a short torque boost to break away.

Physical data: 152x336x233 mm, 5.5 Kg, IP20. The starter has 4 digital inputs and 3 digital outputs, enough for start, stop, reset and a line-contactor command without an interface relay.

In-line or inside-delta: choosing the connection

The ADXT0084 can be wired in two ways, and the choice changes the motor size it can handle at 400 V.

Inside-delta is often chosen when an existing star-delta starter is being replaced, because the six motor cables are already in place. In-line is simpler to wire and to troubleshoot. In both cases the motor protection settings on the starter must match the motor nameplate current.

Choosing the control mode

• Voltage ramp – the simplest setting, suited to lightly loaded fans and machines where a soft mechanical start is the main goal.
• Current ramp and constant current – limit the starting current to a set multiple of motor current, useful where the supply transformer or generator has limited capacity.
• Adaptive control – shapes the acceleration and deceleration profile, which helps reduce water hammer when stopping centrifugal pumps.

Practical points for Oman and GCC sites

Soft starters are widely used on borehole pumps, booster sets, compressors and fans in the region, often supplied from diesel generators or long rural feeders. Limiting the starting current reduces voltage dips that would otherwise trip other loads. Because the built-in bypass carries the running current, heat in the panel is low once the motor is at speed, but the enclosure must still handle the losses during ramping and high summer ambient. Check the ambient rating and the number of starts per hour in the Lovato catalogue against the duty, and derate where the panel runs hot.

What to include in your RFQ

• Order code ADXT0084 and quantity.
• Motor power, full-load current and the planned connection (in-line or inside-delta).
• Control supply voltage available in the panel.
• Load type, starts per hour and any communication or remote keypad accessories required.

Documents and quotation

Attached is the English datasheet that Lovato Electric’s online catalogue generates for ADXT0084; the specification table above reproduces its values. Check the motor nameplate current and starting duty, the main supply voltage, the auxiliary control voltage and the ambient temperature at the panel against your own drawings first; the manufacturer may update datasheet figures without notice. Browse motor soft starters for alternatives. To order ADXT0084, submit the quotation form with your quantity and site; Seven Star LLC, an independent supplier in Muscat, handles the reply.