GE C70 User Manual

7-2 C70 CAPACITOR BANK PROTECTION AND CONTROL SYSTEM – INSTRUCTION MANUAL
COMMANDS MENU CHAPTER 7: COMMANDS AND TARGETS
7
7.1.1 Capacitor bank automatic setting
7.1.1.1 Menu
The relay provides for automatic calculations of proper balancing (matching) factors of the sensitive capacitor bank
protection functions. The following screens display the suggested values of the balancing factors and prompt the user to
apply them. If applied from this command level, a given value is placed into the setting file and applied instantaneously in
all setting groups of the relay with the same source as the active group during the auto-setting procedure.
7.1.1.2 Voltage differential
COMMANDS  CAPACITOR BANK AUTO SETTING  VOLTAGE DIFFERENTIAL  VOLTAGE DIFFERENITAL 1(3)
Use the automatic setting feature when the capacitor bank is online and the 87V function is enabled. For security reasons,
consider applying less sensitive settings during the auto-setting process. Switching temporarily to a different setting group
with less sensitive pickup thresholds is a way to provide the extra security.
The feature can be used with a manual acceptance of the auto-calculated coefficients (the
VOLTAGE DIF 1 AUTO SETTING
command switched to “Manual”), or with an automatic acceptance of the calculated factors (the
VOLTAGE DIF 1 AUTO
SETTING
command switched to “Auto”).
The feature is used as follows.
Application with manual supervision of the automatically calculated factors
When the VOLTAGE DIF 1 AUTO SETTING command is switched to “Manual”, the auto-setting screens, one for each phase,
display the values that balance best the function in a given phase and prompt for permission to apply the calculated value
as a new setting. When confirmed, the auto-selected value gets applied to all setting groups configured with the same
source as the active group during the auto-setting procedure.
After consent to apply the calculated coefficient is received, the "k =?.???? APPLIED" confirmation message displays for the
duration of the flash message time in the second line of the screen. The time-out period is provided for the field staff to
make a note of the newly applied coefficient. However, it is possible to navigate from this screen immediately. The new
setting values can be viewed under the setting menu at any time.
After the process finishes, it is recommended to disable the auto-setting feature. If not disabled by the user, the feature
disables itself when user-initiated front panel interface activity ceases and the C70 display dims itself.
Certain security conditions are checked during the auto-setting process. This includes deviation from the nominal
frequency and verifying that the magnitudes of all three bus voltages are between 0.85 and 1.15 pu. If these conditions are
violated. the SUPV FAIL message displays in the second line.
 CAPACITOR BANK
 AUTO SETTING

 VOLTAGE
 DIFFERENTIAL
See below

 NEUTRAL VOLTAGE
 UNBALANCE
See page 7-3

 PHASE CURRENT
 UNBALANCE
See page 7-4

 NEUTRAL CURRENT
 UNBALANCE
See page 7-5
 VOLTAGE
 DIFFERENTIAL 1

VOLTAGE DIF 1 AUTO
SETTING: Disabled
Range: Disabled, Manual, Auto

V DIF 1A k=####.####
APPLY IN PHS A? No
Range: Yes, No

V DIF 1A k=####.####
APPLY IN PHS B? No
Range: Yes, No

V DIF 1A k=####.####
APPLY IN PHS C? No
Range: Yes, No

GE C70 Specifications

General

Brand	GE
Model	C70
Category	Protection Device
Language	English