External Bias Control

The accessory input enables adjustment of the regulation setpoint through

application of a bias signal from an external device. Any external device that

provides a bias signal within the range of ±3 Vdc may be used. Examples of

external biasing devices include var/power factor controllers, excitation limiters,

and synchronizing/load sharing modules. When the AVC receives a positive voltage

(terminal 2 positive, terminal 3 negative) at the accessory input, the regulation

setpoint decreases. A negative voltage (terminal 2 negative, terminal 3 positive)

at the accessory input increases the regulation setpoint. Figure 9 illustrates

interconnection of the AVC accessory input with an SCP 250 Var/Power Factor

Controller and an EL 200 Minimum/Maximum Excitation Limiter.

When using an external biasing device, ensure that it is configured properly for

use with the AVC63-12 or AVC125-10.