Operating Time Check For Idmt Curve; Testing Idmt - Toshiba GRE110 Instruction Manual

Operating time check for IDMT curve

The testing circuit is shown in Figure 6.5.2.
Single-phase
current
source
+
DC
power
−
supply
Start
Time
counter
Stop
OV
(∗), (∗∗) :
One of the inverse time characteristics can be set, and the output signal numbers of the IDMT
elements are as follows:
Fix the time characteristic to test by setting the scheme switch MOCI on the "PF prot." screen.
"Set.(change)" sub-menu → "Protection" screen → "Change set. (Act gp.= ∗)" screen → "Group∗"
screen → "Trip" screen → "Scheme sw" screen → "PF prot."
The test procedure is as follows:
•
Enter the signal number to observe the operating time at a binary output relay as shown in
Section 6.5.1 and press the ENTER key.
•
Apply a test current and measure the operating time. The magnitude of the test current should
be between 1.2 × I s to 20 × I s , where I s is the current setting.
•
Calculate the theoretical operating time using the characteristic equations shown in Section
2.1.1. Check that the measured operating time is within 5%.
A
Connect the terminal number corresponding to the testing element.
Figure 6.5.2 Testing IDMT
Element Signal No.
OC1-A 51
54
OC2-A
 167 
6 F 2 T 0 1 7 2
GRE110
TB1
∗
- (
)
∗
- (
)
TB2-
∗
BO
TB1 -13
-14
-12
∗∗
( )
∗∗
-
( )