ABB Relion 650 Series Technical Manual page 201

1MRK 506 326-UUS B
Table 104: UC2PTUC (37) Non group settings (basic)
Name Values (Range)
GlobalBaseSelector 1 - 6
6.8.6 Operation principle
Time delayed 2-step undercurrent protection (UC2PTUC, 37) function generates output signals
PICKUP and TRIP. The 2-steps in the function are identical, hence, only step1 is explained below.
UC2PTUC (37) function compares the magnitude of the measured current with a set current level,
I1< . The undercurrent function operates and generates output signals, PICKUP and PU_ST1, when
the magnitude of the measured current is smaller than the set current level
The low current condition also starts a definite time delay,
based on a selected number of phases involved for operation according to setting parameter,
I1Mode . When the low current condition continues for longer time than the set time t1 , the
UC2PTUC (37) function generates trip signals, TRIP and TRST1. The lengths of these signals are
controlled by a pulse timer,
or time delay with the time setting,
An included blocking step is used to block UC2PTUC (37) when the power is shut off. The blocking
step operates when all three phase currents are below the set value of
Step 2 is exactly designed as step 1. All corresponding output signals and settings of step 2 are
suffixed with '2'.
6.8.7 Technical data
Table 105: UC2PTUC (37) Technical data
Function
Low-set step of undercurrent limit, (step 1)
High-set step of undercurrent limit, (step 2)
Time delayed operation of low-set step, (step 1)
Time delayed operation of high-set step, (step 2)
Reset ratio
6.9 Thermal overload protection, one time constant LPTTR
(26)
Line distance protection REL650
Technical manual
Unit Step
- 1
tPulse . The PICKUP and TRIP output signals can be reset instantaneous
tReset1 .
© Copyright 2011 ABB Power Grids. All rights reserved
Default Description
1 Selection of one of the Global Base Value
groups
t1 . The current measuring condition is
Setting range
5.0-100.0% of
steps of 1.0%
5.0-100.0% of
steps of 1.0%
0.000-60.000 s in steps
of 1 ms
0.000-60.000 s in steps
of 1 ms
<105%
Section 6
Current protection
GUID-BCB46004-6306-4876-99AE-7180E00F8351 v2
I1< .
IBlk .
GUID-5051858A-0D3A-40F0-B2E5-199EE0F964D3 v2
Accuracy
IBase in
± 1.0 % of I
n
IBase in
± 1.0 % of I
n
± 0.5 % ± 25 ms
± 0.5 % ± 25 ms
IP14512-1 v4
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