Basler Electric BE1-11m - Manual (Page 91)

9424200996 Rev L 79
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.
Note
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 bad.
Overpower and/or underpower 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
In Total Power mode, if total power is above or below pickup, and in the set direction, the element will pick
up. In modes 1 of 3, 2 of 3, or 3 of 3, a single-phase power pickup value is automatically calculated based
on the three-phase power setting. If the single-phase power is above or below the calculated pickup value
(1 of 3, 2 of 3, or 3 of 3) and in the set direction, the element will pick up. The element will remain in the
picked-up condition until power flow falls below the dropout ratio of 95% of the actual pickup.
To clarify the difference between 3 of 3 and Total Power modes, assume that 3 of 3 mode has been
selected and the three-phase pickup setting is 30 watts. Therefore, the BE1-11m will pick up when each
phase exceeds 10 watts (three-phase setting/3). Alternately, if two phases are zero (0) watts and the third
phase is 50 watts, the BE1-11m will not pickup because two of the phases have not exceeded the single
phase pickup threshold required for 3 of 3 operation. All three phases must exceed the single-phase
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
+ 50 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.
BE1-11m Power (32) Protection