Synchronization Voltage

Voltage is applied to this input and passed through the synchronizing transformer. These voltage signals

are used to define the time reference for the rectifier chassis SCR control pulses. The voltages are also

used for generator voltage metering in applications where the rectifier chassis operating power is supplied

from the generator output (if the Internal mode of the generator voltage sensing is selected (for three

phase applications only)).

Terminal labeling for the synchronization voltage input varies according to the model of IFM-150 (single

phase or three-phase control).

The single-phase IFM-150 accepts synchronization voltage at terminals A1 and B or A2 and B. Terminals

A1 and B are used for synchronization voltage in the 240 Vac or 480 Vac range. Terminals A2 and B are

used for synchronization voltage in the 120 Vac range.

The three-phase IFM-150 accepts synchronization voltage at terminals A, B, and C.

Generator Voltage (B2. B3)

The dc output from the transducer, used to sense the generator voltage, is applied to this input. This

signal is used for generator voltage metering if the external generator voltage sensing mode is selected.

Gate Drive Block (BL+, BL–)

When a contact closure is sensed at this input, SCR firing is blocked and the IFM-150 output is disabled.

Full Invert (INV+, INV–)

The pulse outputs are forced to their maximum delay when a contact closure is sensed at this input. This

results in maximum negative voltage at the exciter output until the field current decays to nearly zero. The

Full Invert contact input is used only on full-control bridges.