3-4
BE1-32R, -32 O/U FUNCTIONAL DESCRIPTION
Sensing Input Types
Type A, Single-Phase Sensing
Refer to Figure 3-6. Type A sensing configurations monitor line-to-neutral voltage and a single-phase current
of a three-phase, four-wire circuit, and calculate the power flowing in the tripping direction. These relays can
also be applied in a three-phase, three-wire system using phase-to-ground voltages. Type A sensing
configurations are not phase rotation sensitive. The range switch for this type sensing is calibrated in single-
phase watts.
Figure 3-6. Type A Sensing
Type B or V, Single-Phase Sensing
Refer to Figure 3-7. Type B or V sensing configurations monitor line-to-line voltage and a single-phase current
of a three-phase, three-wire circuit and calculate the power flowing in the tripping direction. The power equation
assumes balanced conditions. Because the input voltage leads the input current by 30
(assuming unity power
factor), a 30
lagging phase shift network is designed into the voltage input circuit. Type B or V configurations
are phase rotation sensitive. The range switch of this type sensing is also calibrated in single-phase watts.
Figure 3-7. Type B or V Sensing
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