The MLJ is a digital synchronism check relay that measures bus and line voltages,

checking: voltage differences, frequency slip, and phase angle between both voltages

Applications

Generator and network synchronism

Bus or line synchronism check

Protection and Control

Synchronism check operation

Undervoltage supervision

The relay functions in two modes:

• Continuous mode: In this mode synchronism is checked continuously.

• Manual mode: This is activated when voltage is applied through a manually activated input, thus

beginning synchronism control when voltage applied through another digital input for initial checking.

The function of synchronism (with voltage in the line and bus) can be controlled by two undervoltage units,

which allow the synchronism operation when both voltages are higher than the set value.

Additionally, it is equipped with DLDB dead line-dead bus, DLLB dead line-live bus, and LLDB live line-dead

bus, making it possible to select any combination thereof through independent settings.

The basic MLJ1000 equipment and the equipment linkable via RS-485 is mounted in a 2-inch module,

compatible with industrial MID systems, or in a 1/8 rack as an individual relay.