DJMAL and inversion of parameter CDJ

What is the indication of DJMAL?

It is a dry contact input that can be connected to the auxiliary contact of the motor circuit breaker to indicate its state.

For the commutator motor to start operating, it is necessary that, in addition to the command signal, the motor protection circuit breaker is closed. Since the circuit breaker can open, taking the motor out of operation for various reasons, it is important to know its state to assess the readiness of the motor.

The dry contact input that already exists between pins 18 and 30 of the IDM/SDM serves exactly this purpose, and should be wired as follows:

The IDM/SDM has the CTDJ indication in its display, which shows the state of the auxiliary contact of the motor breaker, open or closed. Since this contact is usually supplied with NC logic (closed when the breaker is off), the alarm will be triggered if the CTDJ indication is CLOSED.

CDJ parameter

CDJ is the parameter that allows choosing the mode of the auxiliary motor contact (normal or reversed).

With the inverted logic (INVE in the display), the alarm will not be activated when the CTDJ indicator is OPEN if the auxiliary motor contact is in the closed position.

For a better understanding, the table of indications of auxiliary contact DJMAL follows: