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5 PERIODIC & ACCEPTANCE TESTS
3. Set the relay at the desired pickup TOC and disable the instantaneous unit by setting the instantaneous
multiplier to zero (0).
4. Apply current to the relay and verify that the Pickup LED on the front of the relay lights between 100% and
110% of the pickup TOC setting, and that the trip relay closes thereafter.
5. With the output relay closed, reduce the current applied, verifying that at a value between 95% and 105%
of the pickup TOC, the relay resets, and the Pickup LED turns off.
b) VERIFICATION OF OPERATING TIME
1. With the relay still connected as indicated in Figure 5–1: TEST CONNECTIONS, set the inverse time unit
to minimum pickup and set the corresponding time dial to 5 on a 5 A relay, or 0.5 on a 1 A relay.
2. Successively apply currents of 2, 5, and 10 times pickup TOC at a minimum, verifying that the operating
times are within the margins indicated in the table below.
Table 5–1: INVERSE CHARACTERISTIC OPERATING TIMES
TIMES
PICKUP
INVERSE
TOC
(ANSI)
2
4.28 to 4.73
5
1.93 to 2.13
10
1.32 to 1.45
5
3. For the Definite Time Characteristics, based on any current input, the time should be half of the maximum
value.
c) VERIFICATION OF TIME DIAL
1. Set the relay at the minimum pickup TOC and verify that with an input current of five times (5x) pickup
TOC, the operating time is between the margins shown in the tables below.
Table 5–2: TIME DIAL VERIFICATION – INVERSE TIME
TIME
DIAL
INVERSE
5 A (1 A)
(ANSI)
10 (1)
3.84 to 4.24
7 (0.7)
2.69 to 2.98
3 (0.3)
1.16 to 1.29
1 (0.1)
approx. 0.41
Table 5–3: TIME DIAL VERIFICATION – DEFINITE TIME
TIME DIAL
5 A (1 A)
T
max
10 (1)
1.95 to 2.05
7 (0.7)
1.35 to 1.45
3 (0.3)
0.57 to 0.63
1 (0.1)
approx. 0.20
5-
2
Courtesy of NationalSwitchgear.com
OPERATING TIMES (in seconds)
INVERSE
(BS142)
0.49 to 0.55
8.03 to 8.87
0.21 to 0.25
1.43 to 1.58
0.15 to 0.18
0.77 to 0.85
OPERATING TIMES (in seconds)
INVERSE
(BS142)
4.08 to 4.51
2.84 to 3.14
2.86 to 3.16
2.00 to 2.20
1.24 to 1.37
0.86 to 0.96
0.42 to 0.47
approx. 0.31
OPERATING TIMES (in seconds)
= 2 sec.
T
= 4 sec.
max
3.95 to 4.05
2.75 to 2.85
1.14 to 1.26
approx. 0.40
MDP Digital Time Overcurrent Relay
VERY
LONG TIME
INVERSE
INVERSE
44.8 to 49.5
19.3 to 21.3
11.7 to 12.9
VERY
LONG TIME
INVERSE
INVERSE
38.6 to 42.7
27.0 to 29.9
11.6 to 12.9
3.86 to 4.27
T
= 6 sec.
T
= 8 sec.
max
max
5.45 to 5.05
7.95 to 8.05
4.15 to 4.25
5.55 to 5.65
1.71 to 1.89
2.35 to 2.45
0.57 to 0.67
0.76 to 0.86
GEK-100682D
EXTREMELY
INVERSE
8.24 to 9.11
1.02 to 1.13
0.30 to 0.33
EXTREMELY
INVERSE
2.02 to 2.23
1.42 to 1.57
0.62 to 0.69
approx 0.24
GE Power Management
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