APPLICATION:

The BE3-25 series are synchronizing check relays, also known

as paralleling relays. They are used to ensure that two AC

supplies are synchronized. For a system to be synchronized,

the frequency, phase angle, and voltage must be within preset

limits. The BE3-25-****4 can monitor either utility mains bus

bar and incoming generator, or two generators. 

The BE3-25-****4 offers user adjustment of the reset voltage

from 10 to 30%. This voltage corresponds to 6 to 20 electrical

degrees. The unit compares the input voltage and phase

relationship of the bus bar to that of the generator.

When the signal is within the preset limits, the relay energizes.

The BE3-25-****5 operates as the BE3 25-****4.

but has the additional feature of a dead bus facility.

This enables the relay to energize with a generator supply

only, which is a common requirement when utility mains failure

occurs.