How does it work?

The STS constantly monitors the power quality of both sources taking into account the customer

specified thresholds. In addition, three transfer modes are available to customers to choose from:

A9. DIR always and DIR limited.

A9: this mode is a proprietary method that is to be used only when the phase difference between the

sources is less than a user defined phase angle.

The range of this setting is adjustable up to +/– 30 degrees, and is not recommended for larger phase

differences.

DIR always: this mode allows the SuperSwitch®4 to permanently transfer using the Real Time Flux

Control approach and should result in low inrush regardless of how far the two sources are out of

phase.

DIR limited: this mode is the recommended setting for the SuperSwitch®4. In this mode, a hybrid

approach of A9 and DIR is performed depending on the phase difference between the sources.

Most customers use the recommended setting of DIR limited because the STS will auto select when,

and if, the DIR function is needed depending on the phase difference as illustrated by Figure 1 below.