ZEB – Electronic overload relay with wide-range overload protection

Moeller® series

Motorschutzrelais ZEB

The electronic overload relays ZEB are the perfect solution for enhanced motor protection. The standard motor protection functions such as the protection against overload currents as well as the detection of phase failure and phase unbalance are complemented by the advantages of the electronics.

The electronic overload relays ZEB are self-supplying and draw the energy for the internal electronics from the motor current of the three main phases. Accordingly, connection of an additional power supply is unnecessary, whereby the electronic overload relays can be used as an alternative to conventional bi-metal relays used up to now.

The wide overload setting range of the motor rated current facilitates, in contrast to bi-metal overload relays, a wide-range protection of the motors concerned. The selectable tripping classes up to CLASS 30 also provide optimum protection under normal as well as heavy duty starting conditions. This results in a significant reduction of the number of device variants, leading to savings in inventory costs as well as to simplification in type selection and engineering.

The device variant (ZEB…-GF) also features selectable integrated earth-fault detection to provide additional system protection.

Enhanced availability is ensured, as automatic or manual reset can be set as well as activation or deactivation of the phase loss sensitivity and phase unbalance detection.

Overload relays of the ZEB series are available for motor rated currents up to 100 A for separate mounting or for direct mounting on the contactor DILM.


Motorschutzrelais ZEB
  • Self-supplying electronics avoid the requirement for an external power supply
  • Low number of device variants reduces inventory costs and simplifies selection during engineering
  • Adjustable tripping classes for optimum protection with varying starting conditions
  • Direct mounting on the contactor DILM saves space in the control panel
  • Adjustable automatic / manual reset for enhanced availability
  • Selectable single-phasing sensitivity for enhanced availability
  • Visual device LED overload early warning
  • Integrated earth-fault protection