531X305NTBAPG1 NTB/3TB Terminal Board 531X Series

531X305NTBAPG1 is an NTB/3TB Terminal Board developed by GE under the EX2000 Excitation system. The drive (or exciter) cabinet houses the 531X305NTB (NTB/3TB) board. The drive’s (or exciter’s) connection terminals for the majority of external signal-level I/O are located on the board, along with passive interface circuitry. Plugs 6PL and 8PL from the drive control board, plugs 2PL and 4PL from the power supply board, plug COMPL from the terminal board 3TB, and plugs 2PL and 4PL from external equipment connect to the NTB/3TB.

531X305NTBAPG1 Power Supply

For external use, the NTB/3TB provides the following power outputs:

• Regulated voltages of +5 V dc and 15 V dc, each with a 300 mA current capacity
• Unregulated dc 24 V, 500 mA current capacity
• 120 V ac, 0.5 A of current capacity

Encoder Interface

• A differential A-quad-B encoder interface with a marker channel is included in the NTB/3TB and can be used to connect to the drive.
• On the drive control board, this circuit is optically isolated.
• Jumpers are included in the NTB/3TB to allow the interface to be set up for +5 V or 15 V encoders.

531X305NTBAPG1 Digital Control Inputs

• The NTB/3TB transmits a variety of control inputs to the drive control board. There are 12 general-purpose control inputs (up to 24 V dc) and special-purpose digital inputs (such as RESET and CONTROL ON).
• Depending on whether positive or negative logic is employed, hardware jumpers are used to bias disconnected inputs to +24 or -24 V dc.