Protection Schemes
745
Transformer Management Relay
Commission
ing
http://www.GEindustrial.com/multilin
7–11
GE Multilin
Analog Outputs
1. The analog output settings are located in the
S2 SYSTEM SETUP
!"
ANALOG OUT-
PUTS
setpoints section.
2. Connect a milliammeter to the Analog Output contacts: COM on A5 and Analog
Output 1 on A6, Analog Output 2 on A7, Analog Output 3 on A8, Analog Output
4 on A9, Analog Output 5 on A10, Analog Output 6 on A11, or Analog Output 7
on A12.
3. From the settings used for the tested Analog output, determine the mA range
for the output and the driving signal and its range for the full range of output
current.
4. Apply the input signal and vary its amplitude over the full range and ensure the
Analog Output current is the correct amplitude. Record the results in the table
below. Duplicate as required for each Analog Output.
Tap Position
1. The Analog Input used to sense tap position is programmed with the
S2 SYSTEM
SETUP
!"
ONLOAD TAP CHANGER
setpoints.
2. To verify the operation of this circuit, connect a variable resistor across
terminals A3 and A4. The resistor range should cover the full range of resistance
produced by the tap changer mechanism. The tap position is displayed in
A2
METERING
!"
TAP CHANGER
!
TAP CHANGER POSITION
.
3. Adjust the resistance to simulate the minimum tap position and verify that a “1”
is displayed. Now gradually increase the resistance up to the value which
represents the maximum tap value, verifying that the tap position indicator
tracks the resistance.
Protection Schemes
Precautions
Keep track of modifications/changes made to settings during the
course of these commissioning steps and ensure that all settings are
returned to the ‘in-service’ values at the end of the tests.
Harmonic Restrained
Percent Differential
a) Description
The harmonic restrained percent differential element setpoints are located in
S4
ELEMENTS
!"
DIFFERENTIAL
!
PERCENT DIFFERENTIAL
. Disable all other protection
elements to ensure that trip relay(s) and auxiliary relays are operated by element
under test only. With a multimeter, monitor the appropriate output contact(s) per
intended settings of the FlexLogic™. Refer to the relay settings to find out which
relay(s) should operate when a given element operates.
Table 7–2: Analog Output Calibration Results
Analog Output Number: __________
Analog Output Min.: ______________
Analog Output Value: ___________
Analog Output Max.: ___________
Analog Output Range: ____________
Input Signal Amplitude
(% of full range)
Expected mA Output
Measured mA Output
0
25
50
75
100
CAUTION
Summary of Contents for Multilin 745
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