Basler Electric BE1-11m - Manual (Page 93)

9424200996 Rev L 81
Assuming polarity current and voltage connections as shown in Figure 55, forward power is defined as
flowing into the Area EPS and reverse power is defined as flowing into the Local EPS. For this
application, the 32 element should be set to trip for minimum underpower in the reverse direction (to the
Local EPS). Therefore, the settings would be Reverse, Under, and 1 watt. To increase sensitivity, mode
selection should be 3 of 3 which requires each phase power to fall below
⅓ of the three-phase power
setting or 0.33 watts. Assume that normal power absorbed by the load is 4 kW in the reverse or negative
direction on our scale. If load is suddenly lost at the industrial plant while the peak shaving generation is
running, power may flow towards the Area EPS depending on the load to generation ratio. What was a
negative 4 kW passes through 0 watts on its way to some positive power level. However, in doing so,
passes through the negative underpower trip threshold of Reverse, Under, 0.33 watts/phase, resulting in
a 32 trip and opening of the intertie circuit breaker. From negative 0.33 to positive infinity, the 32 element
remains in a picked up condition as shown in Figure 56. A trip time delay should be included to ensure
that the 32 element does not operate for a transient power condition.
Pickup and Trip
The Pickup output occurs first, followed by the Trip output.
Pickup
The Pickup output occurs when the calculated real power increases above or decreases below the
threshold established by the Pickup setting. In BESTlogicPlus, the Pickup output can be connected to
other logic elements to annunciate the condition, control other elements in logic, and start the fault
recorder (logic element FALTTRIG).
Assertion of the Pickup output initiates a definite timer that begins timing to a trip. The duration of the
timer is established by the Time Delay setting. A Time Delay setting of zero (0) makes the 32 element
instantaneous with no intentional time delay.
If the pickup condition subsides before the element delay expires, the timer and Pickup output are reset,
no corrective action is taken, and the element is rearmed for any other occurrences of over/under power.
Trip
The Trip output becomes true if a power pickup condition exists for the duration of the element Time
Delay. In BESTlogicPlus, the Trip output can be connected to other logic elements and to a physical relay
output to annunciate the condition and to initiate corrective action. If a target is enabled for the element,
the BE1-11m will record a target when the Trip output becomes true. See the Fault Reporting chapter for
more information about target reporting.
Element Blocking
Fuse Loss
The fuse loss (60FL) element of the BE1-11m can be used to block 32 protection when fuse loss or loss
of potential is detected in a three-phase system.
If the 60FL element trip logic is true and Block Power/Power Factor is enabled, all functions that use
power measurements are blocked. See the
Fuse Loss (60FL) chapter for more information on the 60FL
function.
Protective elements blocked by 60FL should be set so that trip times are 60 milliseconds or greater to
assure proper coordination of blocking.
Block Logic Input
The Block input provides logic-supervision control of the element. When true, the Block input disables the
element by forcing the Trip and Pickup outputs to logic 0 and resetting the element timer. Connect the
element Block input to the desired logic in BESTlogicPlus. When the element is initially selected from the
Elements view, the default condition of the Block input is a logic 0.
BE1-11m Power (32) Protection