Starting resistors

Resistors are also used for motor starting to limit the inrush current. Even if electronic starters, softstarters and AC variable speed drives, have reduced the need for starting resistors, there are still applications when the resistor is a practical and cost-effective solution. We can supply resistors for most starting applications.

Wound rotor motor starting resistors
Wound rotor rotors with slip rings are still used in weaker networks or when the required load torque is very large. During start-up multiple sets of resistors are connected across the slip rings to control the starting current. We can supply rotor starting resistor for both low and medium voltage motors.

Closed transition resistors for Star-Delta starters
Star-delta is a commonly used reduced current starting method. However, one disadvantage is that a voltage spike occurs during transition from star to delta position. The voltage spike can be reduced by using three small resistors that are shortly put in circuit during start. The method is called “Closed Transition” and is commonly used in North America. We can supply resistor elements to be installed in the starter.

DC motors
DC motors are commonly used in critical applications, supplied direct from batteries. The starting resistor limit the starting current to the required level. Starting resistors can be supplied as loose resistor elements on mounting brackets or as enclosed starting resistors, ingress protection IP 20.