What is the Starter 3-Phase Star-Delta?
The HPzenAi Starter 3-Phase Star-Delta (SP-3P-SD) is a complete smart motor starter for large three-phase induction motors that require reduced-voltage starting. It uses the star-delta (Y-Δ) starting method: the motor windings are first connected in star (Y) at reduced torque and current, then automatically switched to delta (Δ) for full-power operation. The SP-3P-SD includes three contactors (main, star, delta), an overload relay, and a built-in MX-3P-SD IoT module with configurable star-delta transition timer, phase-loss protection, and HPzenAi gateway connectivity.
Complete Star-Delta Assembly
Main, star, and delta contactors plus overload relay pre-wired and assembled — connect 6-wire motor and three-phase supply
Reduced-Voltage Starting
Star-delta starting reduces motor starting current to approximately 1/3 of full DOL starting current — protects supply infrastructure from current spikes on large motors
Configurable Transition Timer
Adjustable star-to-delta transition time via the HPzenAi app — set per motor type and load to ensure smooth transition without torque dip or current spike
Phase-Loss & Overload Protection
Built-in phase-loss detection plus adjustable thermal overload relay — full hardware and software motor protection in one assembly
Product Specifications
| Attribute | Detail |
|---|---|
| Assembly Type | Complete star-delta starter — main, star, and delta contactors + overload relay + MX-3P-SD IoT module |
| Motor Phase | Three-phase, 415V AC |
| Motor Wiring | 6-terminal motor (U1, V1, W1, U2, V2, W2) — required for star-delta connection |
| Supply Input | R, S, T (three-phase from switch-disconnector) |
| Contactor Channels | 3 channels: MAIN, STAR, DELTA — sequenced by built-in MX-3P-SD timer |
| Star-Delta Timer | Adjustable 2–30 seconds via HPzenAi app (factory default: 8 seconds) |
| Overload Relay | Thermal overload relay with adjustable FLA dial — set to motor nameplate current at delta (full-load) |
| Phase-Loss Detection | Built-in — trips on loss of any phase |
| IoT Module | Built-in MX-3P-SD — RS485 Modbus RTU, 12V DC control supply |
| Gateway Compatibility | HPzenAi GW-W1 (Wi-Fi) · GW-XR1 (SIM/RF) |
| Status Indicator | Multi-colour LED: green (running), amber (fault), red (phase loss), blue (pairing) |
Applications & Use Cases
| Application | Description |
|---|---|
| Large Three-Phase Pumps (15–75 kW) | Reduced-voltage starting for large centrifugal and submersible pumps where DOL starting current is too high for the supply infrastructure |
| Compressors & Air Handling Units | Star-delta starting for large air compressors, blowers, and AHU fans with high-inertia loads |
| Agricultural Pump Stations | Smart remote-controlled star-delta starting for large irrigation pump motors in rural areas with limited supply capacity |
| Industrial Motor Control Panels | IOT-enabled star-delta motor starter for production machinery, conveyors, and industrial fans |
| OEM High-Power Panel Builds | Complete smart star-delta assembly for OEM panel builders — IoT ready out of the box |
Available Models
SP-3P-SD-18
Star-Delta Starter — 18A (up to 11 kW)
SP-3P-SD-32
Star-Delta Starter — 32A (up to 22 kW)
SP-3P-SD-65
Star-Delta Starter — 65A (up to 45 kW)