9424200996 84-47
BE1-11m Settings Calculation Examples
Figure 84-59. Protection, Voltage, Undervoltage (27P-2) Screen
Overvoltage (59P-1)
The 59-1 protection element is set to trip when source voltage is too large, and is especially important in a
synchronous motor. Because the motor is a constant kVA (power) device, the result of overvoltage is to
decrease the load current and the power factor if no additional excitation is added. In addition, newer
motors use less iron in the core and therefore the V/Hz ratio can cause air-gap flux saturation and
subsequent motor heating. The Pickup setting is calculated in Equation 84-44.
= 110%
1
= 1.10 12,000
1
100
= 132
Equation 84-44. 59P-1 Pickup
Select Three of Three mode, set the Pickup setting to 132 Secondary V, and set the Time Delay to 1000
ms to avoid tripping on spikes in the system. See Figure 84-60.
To Next Page
Loading...
