Ex d Star Delta starter

A Flameproof Star Delta Starter is an essential component in industrial settings where explosion-proof equipment is required to enhance safety. This specialized starter is designed to minimize the risk of ignition and explosions in hazardous environments by containing any potential sparks or flames that may result from electrical faults. These starters are constructed with robust enclosures that can withstand and contain any internal explosion, thus preventing it from causing harm outside the enclosure.

The Star Delta Starter is an essential electrical device that plays a pivotal role in the efficient and smooth operation of large induction motors. In the realm of electric motors, most smaller to moderately sized induction motors are conventionally started directly on the line, connecting them directly to the power source without any additional components. However, this method becomes impractical and even problematic when dealing with very large motors, typically characterized by their substantial power requirements.

The crux of the issue lies in the considerable starting current surges that occur during the initiation of these massive motors. The starting process for such motors draws a significant amount of current, which can lead to voltage disturbances on the supply lines. These voltage disturbances can not only cause a dip in the supply voltage but can also result in fluctuations and variations that might negatively affect other equipment and devices connected to the same electrical system. This is particularly critical in industrial settings where downtime and disruptions to the manufacturing process can lead to substantial losses.

To mitigate this issue, the Star Delta Starter comes into play. It offers a method of reducing the inrush current during the starting of large induction motors. The Star Delta Starter operates in two distinct configurations, the “star” (Wye) configuration for initial starting and the “delta” configuration for normal operation. During the starting phase, the motor is initially connected in a star configuration, which reduces the voltage across each winding and consequently decreases the starting current. This lower starting current not only alleviates the voltage disturbances on the supply lines but also prolongs the lifespan of the motor by reducing mechanical stress.

Once the motor reaches a certain speed, the starter switches to the delta configuration for continuous operation. In this way, the Star Delta Starter provides a practical solution to the challenges posed by very large induction motors, ensuring a smoother startup process, minimizing voltage disruptions, and enhancing the overall efficiency and reliability of the electrical system, especially in industrial and commercial applications.

Additional information

Product Certifications

NEC 505(North America)
NEC 500(North America)

Area Clasification

Gas: Zone 1 & 2
Dust: Zone 21 & 22
Gas group IIA,IIB, IIC

Standards / Norms

IEC / EN 60079-0
IEC / EN 60079-1
IEC / EN 60079-14
IEC / EN 60079-31

Applicable Industry / Area


Application Examples

Dosing pump
Recovery pump
Conveyor belt
Hydraulic lift
Shale shaker
Degasser pump