Ground Fault Current Functions; Rtd Measurement Tests; Table 5-1: Rtd Resistance Vs. Temperature - GE 269Plus Instruction Manual

GROUND FAULT CURRENT FUNCTIONS

The ground fault current function uses digital current information converted from the analog ground fault CT
input. The 269Plus must read the injected ground fault current correctly in order for the ground fault function to
operate properly. Using factory default setpoints to test the ground fault input circuitry, pass a phase current
conductor through the ground fault CT window as shown in Figure 5–1: SECONDARY INJECTION TEST (AC
INPUT TO 269Plus). The actual injected current should then be the same as the
play in Actual Values. If the injected cur-rent is adjusted to over 4.0 A for longer than 10.0 seconds the ground
fault alarm should become active. If over 8.0 A is injected for more than 50 ms, a ground fault trip should occur.
These tests can be performed for other CT ratios and setpoints.
The correct operation of each of the RTD inputs can be tested by simulating RTDs with potentiometers. To test
a 269Plus configured for use with 100 Ω platinum RTDs, 100 Ω potentiometers and resistors can be used.
These should be connected to each RTD as shown in Figure 5–1: SECONDARY INJECTION TEST (AC
INPUT TO 269Plus) on page 5–2. The table below shows RTD resistances for various temperatures. Individ-
ual, actual stator and bearing RTD temperatures can be viewed in Actual Values page 2.
Table 5–1: RTD RESISTANCE VS. TEMPERATURE
TEMP
(°C)
100 Ω Ω Ω Ω P
0 100.00
5
10 103.90
20 107.79
30 111.67
40 115.54
50 119.39
60 123.24
70 127.07
80 130.89
90 134.70
100 138.50
110 142.99
120 146.06
130 149.82
140 153.58
150 157.32
160 161.04
170 164.76
180 168.47
190 172.46
200 175.84
Note: * = DIN 43760. To test overtemperature trip/alarm functions the simulated RTD potentiometers should be
adjusted to correspond to high RTD temperatures. Stator RTD Voting in Setpoint Values page 5 should be
defeated first. This allows for individual trip/alarm overtemperature testing.
5-
4
Courtesy of NationalSwitchgear.com
RESISTANCE
120 Ω Ω Ω Ω N 100 Ω Ω Ω Ω N
*
T I
120.00
127.17
134.52
142.06
149.79
157.74
165.90
174.25
182.84
191.64
200.64
209.85
219.29
228.96
238.85
248.95
259.30
269.91
280.77
291.96
303.46
269Plus Motor Management Relay
5.4 GROUND FAULT CURRENT FUNCTIONS
10 Ω Ω Ω Ω C
I U
100.0 9.04
105.6 9.42
111.2 9.81
117.1 10.19
123.0 10.58
129.1 10.97
135.3 11.35
141.7 11.74
148.3 12.12
154.9 12.51
161.8 12.90
168.8 13.28
176.0 13.67
183.3 14.06
190.9 14.44
198.7 14.88
206.6 15.22
214.8 15.61
223.2 16.00
231.6 16.39
240.0 16.78
5 RELAY TESTING
G R O U N D F A U L T C U R R E N T

5.5 RTD MEASUREMENT TESTS

GE Power Management
dis-