Schweitzer Engineering Laboratories SEL-351 - Settings Ranges (51 PT Element Example)

Date Code 20001006 Overcurrent, Voltage, Synchronism Check, Frequency, and Power Elements 3-17
SEL-351 Instruction Manual
Settings Ranges (51PT Element Example)
Besides the settings involved with the Torque Control Switch operation in Figure 3.14, the 51PT
phase time-overcurrent element has the following settings:
Table 3.2: Phase Time-Overcurrent Element (Maximum Phase) Settings
Setting Definition Range
51PP pickup 0.50 - 16.00 A secondary (5 A nominal phase current
inputs, IA, IB, IC)
0.10 - 3.20 A secondary (1 A nominal phase current
inputs, IA, IB, IC)
51PC curve type U1 - U5 (US curves) see Figure 9.1 - Figure 9.10
C1 - C5 (IEC curves)
51PTD time dial 0.50 - 15.00 (US curves) see Figure 9.1 - Figure 9.10
0.05 - 1.00 (IEC curves)
51PRS electromechanical
reset timing
Y, N
51PTC SELOGIC Control
Equation torque
control setting
Relay Word bits referenced in Table 9.3
or
set directly to logical 1 (=1) - see note below
Note: SELOGIC Control Equation torque control settings (e.g., 51PTC) cannot be set directly to
logical 0.
See Section 9: Setting the Relay for additional time-overcurrent element setting information.
Courtesy of NationalSwitchgear.com