IS200EAUDH1A

IS200EAUDH1A is an Excitation Control High-Speed Contactor Driver Board manufactured and designed by General Electric as part of the EX2100e Series used in GE Excitation Control Systems. When the EX2100e Excitation Control High-speed Contactor Driver (EAUD) board is a daughterboard put on the EX2100e Excitation Control Auxiliary Interface (EAUX) board as an accessory. It provides high-speed pickup and dropout capability for the two 41DC contactor driver circuits on the EAUX board. One or two contactors with unique low-voltage coils are utilized with the EAUD. As opposed to the standard 125 V dc rating, these coils typically have a voltage rating of 30 V to 32 V dc. Due to the reduced voltage rating, the entire 125 V dc bus voltage can be applied for the first 150 ms after the EAUX issues the proper command. As a result, the contactor armature can close more quickly and consistently.

INSTALLATION:

When an application is created in a factory, the EAUD board is typically provided pre-mounted to the EAUX board. If the EAUX and EAUD are provided as part of a field-installed kit, they need to be installed in a sterile area where they won't be subjected to heat-generating machinery, electromagnetic interference, or environmental circumstances that go beyond what the board is designed for. Additionally, they must be put in a place where people won't be exposed to the excitation equipment's shock or arc flash threats.

OPERATION:

The following combinations and operating modes for EAUX and EAUD are acceptable for controlling either one or two 41DC contactors in the EX2100e: EAUX versus EAUD The contactor coil receives consistent 125 V dc from the EAUX (s). EAUD and EAUX The EAUX have boost start and high-speed dropout modes and controls contactor coil current to 1.5 A dc. The switching MOSFET (transistor) is gated on constantly to apply 125 V dc to the contactor coil when EAUX is operated without EAUD.

To enable PWM control of the coil when EAUD is present, EAUD seizes control of the MOSFET gating. For 150 milliseconds at the beginning of each start, a full 125 V dc is supplied to the coil to make sure the contactor is engaged. Then, using a 1.5 kHz PWM control circuit, the EAUD circuitry adjusts the coil current to 1.5 A utilizing coil current feedback. EAUD supplies a low-impedance flyback circuit for effective coil current freewheeling during the PWM off-state. The coil quickly de-energizes through the discharge resistor on EAUX when the flyback circuit is disengaged during stop mode.