9424200996 16-1
BE1-11m Power (32) Protection
16 • Power (32) Protection
The power (32) element monitors three-phase real power (watts). The element can be configured to
protect against overpower or underpower conditions.
Element logic connections are made on the BESTlogic™Plus screen in BESTCOMSPlus® and element
operational settings are configured on the Power settings screen in BESTCOMSPlus. A summary of the
logic inputs and outputs and operational settings appears at the end of this chapter.
BE1-11m protection systems enabled for IEC-61850 communication
(style Mxxxx5xxxxxxxx) have their power protection element fixed at
one underpower element.
BESTCOMSPlus Navigation Path: Settings Explorer, Protection, Power, Power (32)
HMI Navigation Path: Settings Explorer, Protection, Settings Group x (where x = 0 to 3), Power
Protection, Power 32
Element Operation
Power protection can be used in applications where excessive power flow in the tripping direction is
undesirable. Directional power protection is desirable in applications where:
• Reduced power can indicate a loss of load on the motor.
• Power flows into the secondary of a station distribution transformer, indicating an industrial or
private customer is supplying power into the utility system.
• Excessive load has been connected to a system.
• Overload has been placed on a distribution system.
• Overspeeding is a prime concern.
• An open breaker creates an overload on a local generation facility.
Mode
Four modes of protection are available. One of Three mode activates protection when the power on one
of the three phases exceeds the Pickup setting. Two of Three mode activates protection when the power
on any two of the three phases exceeds the Pickup setting. Three of Three mode activates protection
when the power on all three phases exceeds the Pickup setting. Total Power mode activates protection
when the total power exceeds the Pickup setting. The element remains in the picked-up condition until
power flow falls below the dropout ratio of 95% of the actual pickup.
To clarify the difference between Three of Three and Total Power modes, assume that Two of Three
mode has been selected and the pickup setting is 30 watts. Therefore, the BE1-11m picks up when two of
the three phases have exceeded 30 watts. Alternately, if two phases are zero (0) watts and the third
phase is 70 watts, the BE1-11m does not pickup because two of the phases have not exceeded the
pickup threshold required for operation in Two of Three mode. Any two phases must exceed the pickup
threshold for operation to occur. However, if the 32 element was set for Total Power mode, the same
power values previously mentioned would result in a pickup condition because “Total Power” (0 + 0 + 70
watts) exceeds the three-phase pickup setting of 30 watts. For details on power calculations, refer to the
Configuration chapter.
Bus CT Configuration
On protection systems equipped with two sets of CTs, the power element can monitor CT circuit 1 or CT
circuit 2. The CT source is selected on the Sensing Transformers settings screen in BESTCOMSPlus.
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