CU90N – Voltage regulating or equalizing unit
The CU90N unit belongs to SIGMA-N digital protection line and it performs functions as voltage regulating unit for transformers equipped with tap changer or voltage equalizing unit for generator paralleling (jointly with the SCK4N unit it performs function as automatic synchronizing and coupler device).
The user can select one of the functional modes listed below:
| FUNCTIONS | ANSI |
|
Voltage regulating unit for tap changer control |
90 |
|
Voltage equalizer for automatic synchronizing of generators |
25A |
All the functions of the unit are fully programmable by front panel keyboard or through a RS485 serial interface using a personal computer with set-up program; furthermore the relay can be programmed through a remote control and monitoring system.
Operating modes – the CU90N unit manages the following functional modes:
- voltage regulating unit for transformers equipped with tap changer
- voltage equalizer for generator paralleling
Two output relays can be programmed to issue raise (AUM) or lower (DIM) commands; the commands can be issued as:
- definite time
- dependent time (function of the voltage difference)
- continue commands
