Low-voltage Circuit BreakersEarth Leakage Relays

• Ground fault selective coordination can be achieved by installing a time-delay type on the main line and a high-speed type on the branch.
• Time-delay types include the ZBA/ZSA/ZHA/ZLA model.
• Use the ZSA/ZHA/ZLA model if you need 415V, a built-in connection type, and also alarm output.
• The power supply for the earth leakage relay can be made separate.

To reset the system automatically

Use the ZBA/ZHA model, and connect the control power supply to the load side of the MCCB. (No earth leakage indicator)

To indicate earth leakage current

When using the ZBA/ZHA model, connect the control power supply to the line side of the MCCB or to a separate power supply. The MCCB should be turned on again after pressing the reset button.

• Use the ZBA or ZSA/ZHA/ZLA model.
• The figure shows an earth leakage indicator using the ZBA model, but to reset automatically, connect the control power supply to the load side of the electromagnetic contactor.
• Use the ZSA/ZHA/ZLA model if you need 415V, a built-in connection type, and also alarm output.

• Use the ZBA or ZSA/ZHA/ZLA model.

• Use the ZAA model in combination with a timer.
• When a ground fault is detected, the circuit is interrupted the time set on timer.
• If the ground fault ceases before reaching the time set on timer, the timer will automatically reset itself.

• In combination with measurement and control devices, leakage current values are measured.

• Use the ZAA model.
• When the ground fault ceases, the system automatically resets, and the alarm stops.