Basler Electric BE1-11m - Manual (Page 571)

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Figure 394. Protection, Current, Instantaneous Undercurrent (37) Screen
Protection - Voltage
Two undervoltage protection elements are used to monitor undervoltage conditions.
Undervoltage (27P-1) Sag
When the motor is running, undervoltage conditions can jeopardize production (motor speed), cause the
synchronous motor to slip a pole, or affect electronic and digital controls. When running voltage dips
occur, the motor should be disconnected quickly. Set the 27P-1 protection element active in running
mode only for 90 percent per the NEMA MG-1 standard. A delay of 100 ms will ride through fast voltage
transients and prevent false tripping. The pickup setting is calculated in Equation 78.
𝑃𝑖𝑐𝑘𝑢𝑝 = 90% ∙ 𝑁𝑜𝑚𝑖𝑛𝑎𝑙 𝑉𝑜𝑙𝑡𝑎𝑔𝑒 ∙
1
𝑃𝑇𝑅
= 0.90 ∙ 12,000 ∙
1
100
= 108 𝑉 𝑠𝑒𝑐𝑜𝑛𝑑𝑎𝑟𝑦
Equation 78. 27P-1 Pickup
There is no need to set the Inhibit Level because the element is active only during the running mode as
shown in the logic, Figure 406.
Select Three of Three mode, set the Pickup setting to 108 V. The delay should be set as short as
possible, and longer than the start time of other motors on the bus. Because there are no other motors in
this example, set the Time Delay to 100 ms as shown in Figure 395.
BE1-11m Settings Calculation Examples