Prime Series — Star DeltaThree Phase Motor Starter · Fully Automatic

A Star Delta starter is a motor starting method that first connects the motor windings in a Star configuration to limit inrush current, then switches to a Delta configuration for full-voltage running once the motor has picked up speed.

Star Delta starters are typically recommended for three-phase induction motors from around 7.5 HP upward, where a Direct-On-Line (DOL) start would draw too much inrush current for the supply or upstream protection.

Yes. It is suitable for submersible and centrifugal pump motors within its 7.5 HP to 125 HP range, in addition to compressors, HVAC and general industrial motors.

Yes, Prime Series — Star Delta is suitable for three-phase compressor motors within its rated HP range.

7.5 HP to 125 HP, across 14 model references.

A DOL (Direct-On-Line) starter connects the motor straight to full line voltage, giving a simple start but a higher inrush current. A Star Delta starter starts the motor in Star first to reduce that inrush current, then switches to Delta for full running torque — better suited to larger motors or weaker supplies.

Single phasing, reverse phasing, phase unbalance, over voltage, under voltage, overload and short-circuit protection are built in, with dry run protection available as an add-on.

Dry run protection is available as an optional add-on, not a standard inclusion — see the add-ons list for pricing.

It means dry-run protection (which stops the motor when a pump loses prime or runs without load) is available if you request it, at an additional cost, rather than being fitted on every unit by default.

Yes, Prime Series — Star Delta supports remote trip and external command signals, so it can be integrated with SCADA, a BMS, or a level controller.

Yes, Subtech offers custom panel manufacturing — enclosure size, ratings, and add-ons like dry-run sensing can be adapted to your requirement.

Standard models typically ship within 3-5 working days; customised configurations may take 7-15 working days depending on complexity.

Yes, Subtech provides installation guidance and technical support, with on-site commissioning support available for bulk orders.

Yes, it is suitable for agricultural motor loads such as larger irrigation pumps within its HP range.

Yes, it is designed for general industrial and factory motor loads, including conveyors and processing machinery.

The relay range is the adjustable current band (in Amps) that the overload relay is set to protect a specific motor's full load current — each model in the selection guide lists its relay range.

An MCB (Miniature Circuit Breaker) is used on the smaller-rated models for overload/short-circuit protection, while an MCCB (Moulded Case Circuit Breaker) is used on higher-rated models where higher current-carrying and breaking capacity is needed — see the selection guide for which each reference uses.

SDP30L or SDP30 (30 HP, 22 kW) — SDP30L uses MCCB protection in a compact enclosure, while SDP30 uses a larger enclosure; check the selection guide for exact relay ranges.

SDP75 (75 HP, 56 kW, MCCB protection) is the reference for a 75 HP motor.

Listed MRPs are ex-GST and ex-installation; contact our sales team for a full quote including applicable taxes.

Yes, we offer competitive bulk pricing for dealers, distributors, contractors and project orders.

Yes, it is suitable for HVAC blower and compressor motors within its rated HP range.

Yes, the Star-Delta starting method reduces inrush current compared to a direct-on-line start.

Yes, reverse phasing protection is a standard built-in protection on Prime Series — Star Delta.

Use the 'Get Best Price' quote form on this page with your required HP and quantity, or contact our sales team directly for a project quote.

Subtech provides a standard manufacturer warranty on this product; terms may vary by model and configuration — contact our sales team for details.

A 2-piece sensor set for water level control is available as an add-on for pump automation use cases — see the add-ons list for pricing.

The 85 HP, 100 HP and 125 HP references (SDP85, SDP100, SDP125) are built-to-order and priced On Request, while 7.5 HP to 75 HP models have listed MRPs and standard pack quantities.