Wye Versus Delta Voltage Transformers; Frequency Protection (81); Frequency Protection Settings - Eaton Cutler-Hammer FP-5000 Instructions Manual

Page 8-10

8.7 Wye versus Delta Voltage Transformers

The FP-5000 requires setting of system configuration parameters
for proper operation of all system functions (see programming
Section 5.1). All voltage settings are based on the VT input
configuration. Both wye (φ - G) and Delta (φ - φ) voltage connections
are supported. For wye-connected systems, the voltage settings are
based on phase-to-ground voltages. Voltage settings are based on
phase-to-phase voltages for delta-connected systems.

8.8 Frequency Protection (81)

The FP-5000 includes protective functions for detecting
under-frequency and over-frequency conditions. Two elements
are provided for each function so alarm and trip levels can be set
independently. Each of the frequency protection functions has
a Threshold and a Delay setting. The time delay is provided for
coordination with other devices. If the voltage on phase A drops
below 10 volts, the under-frequency and over-frequency functions
are disabled.
An over-frequency pickup occurs when the measured frequency
exceeds the over-frequency Threshold setting. The over-frequency
trip is set when the over-frequency condition exists for the delay
time specified. The over-frequency pickup and trip are reset when
the frequency drops below the over-frequency Threshold setting.
An under-frequency pickup occurs when the measured frequency
drops below the under-frequency Threshold setting. The under-
frequency trip is set when the under-frequency condition exists for
the delay time specified. The under-frequency pickup and trip is
reset when the frequency raises above the under-frequency
Threshold setting.
The settings for the over-frequency and under-frequency functions
are shown in Section 5, Programming and are repeated in Table 8.5.
Table 8.5 Frequency Protection Settings
Parameter Range
81U-1 Under 45 to 65 Hz,
Frequency Disabled
Threshold
81U-1 Under 0 to 9999 Cycles
Frequency
Time Delay
81O-1 Over 45 to 65 Hz,
Frequency Disabled
Threshold
81O-1 Over 0 to 9999 Cycles
Frequency
Time Delay
81U-2 Under 45 to 65 Hz,
Frequency Disabled
Threshold
81U-2 Under 0 to 9999 Cycles
Frequency
Time Delay
81O-2 Over 45 to 65 Hz,
Frequency Disabled
Threshold
81O-2 Over 0 to 9999 Cycles
Frequency
Time Delay
IL17569
Step
0.1 Hz
1 Cycle
0.1 Hz
1 Cycle
0.1 Hz
1 Cycle
0.1 Hz
1 Cycle
Effective June, 2001