ABB 23BA23 Board Command Output Monitor Module Board

APPLICATIONS

The 23BA23 board is used for the remote terminal unit RTU560.

The 23BA23 board should be installed if you need to check the output circuitry for object commands before issuing the actual command.

The 23BA23 board performs an “n select 1” check. It checks whether only one intermediate relay is activated in the output circuit.

This is only feasible if all mutually exclusive relays connected to a check circuit have the same resistance value. have the same resistance value.

23BA23 The board allows two separate check circuits to be used to check two different types of interlocking relays.

The allowable tolerance ranges are defined by parameters.

A maximum of 16 23BA23 boards can be used with one RTU560.

In RTU560 systems, the 23BA23 board is only functionally and pinout compatible with the 23BA22 board.

The 23BA23 board is only functionally and pin compatible with the 23BA22 board in an RTU560 system.

The basic additional tasks are as follows

Checking the galvanic isolation of the circuit

Suppress line frequency during measurement

Characteristics

Figure 1 shows the connection of the binary output boards 23BA20 and 23BA23 at two-pole startup for (n select 1) checking.

The check circuit for measuring the relay coil resistance is galvanically isolated from the electronic voltage and the switching voltage (UD) of the intermediate relay.

This is achieved by means of galvanically isolated DC/DC converters and optocouplers.

No auxiliary test voltage is required. During the measurement, the 23BA23 board switches the corresponding check circuit (P1 or P2) to both poles, thus separating the two.

During the check (1 out of n), the 23BA23 board measures the resistance value in the output circuit and compares this value with the configured upper and lower limits.

If the resistance value is within the limit values, the selected interlock relay can be activated. The object command will be acknowledged.

If the measured resistance value is outside the permissible range, the 23BA23 blocks the output and displays an error to the CMU (CMU = communication unit).

The CMU controls and coordinates the corresponding 23BA20 and 23BA23 boards.

When 23BA20 is switched on, 23BA23 receives the check command and outputs the target command.

The 23BA23 switches the output circuit to the check circuit via relay k3 (check circuit 1) or relay k5 (check circuit 2).

The output constant current is determined by the configured upper coil resistance. If the measured resistance value is within tolerance.

then relay k3 (k5) is switched off and relay k2 (k4) is switched on. Subsequently, relay k1 switches the selected intermediate relay and releases the object command.

The limit values for the coil resistance of the interlocking relays can be adjusted by means of parameters in the range from 100 ȍ to 10 000 ȍ in steps of 10 ȍ.

The line frequency ripple voltage will be filtered by the A/D converter.

By using an additional booster relay, it is possible to activate the process relay on the electrical device (isolator, circuit breaker) directly (fig. 2).

At the command output, it is not k1 that switches the output circuit itself, but the boost relay (KB).

The boost relay connects the switching voltage UD1 to the process relay with the higher switching current via relays kB and k2 (k4).

This ensures that relay contacts k2 (k4) of the 23BA23 and k01 to k18 of the 23BA20 are switched without load.

The selection of the booster relay depends on the switching capacity of the electrical equipment. Consideration must be given to not exceeding the relay characteristics of the output boards 23BA20 and 23BA23.

For diagnostic purposes, switching of the switching voltage can be inhibited by pressing the LOCAL key (LOC). Relays k2 (k4) and k1 will be blocked.

All other output functions (including 1 out of n times) will be performed.

To ensure proper output, the board performs several monitoring functions before and during the commanded output:

Monitors output duration and resets in the event of a fault.

Monitors switching voltage before and during commanded outputs