GE C70

CHAPTER 5: SETTINGS GROUPED ELEMENTS
C70 CAPACITOR BANK PROTECTION AND CONTROL SYSTEM – INSTRUCTION MANUAL 5-205
5
The C70 contains protection elements for neutral time overcurrent (ANSI device 51G), neutral instantaneous overcurrent
(ANSI device 50G), and neutral current unbalance (ANSI device 60N). A maximum of six ground time overcurrent and 12
ground instantaneous overcurrent elements are available, dependent on the CT/VT modules ordered with the relay. Three
neutral current unbalance elements are available.
5.7.4.2 Neutral time overcurrent (ANSI 51N, IEC PTOC)
SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  NEUTRAL CURRENT  NEUTRAL TOC1(6)
The neutral time overcurrent element can provide a desired time-delay operating characteristic versus the applied current
or be used as a simple definite time element. The neutral current input value is a quantity calculated as 3Io from the phase
currents and can be programmed as fundamental phasor magnitude or total waveform RMS magnitude as required by the
application.
Two methods of resetting operation are available: “Timed” and “Instantaneous” (see the Inverse TOC Curve Characteristics
section for details on curve setup, trip times, and reset operation). When the element is blocked, the time accumulator
resets according to the reset characteristic. For example, if the element reset characteristic is set to “Instantaneous” and
the element is blocked, the time accumulator clears immediately.

 NEUTRAL TOC 6


 NEUTRAL IOC 1

See page 5-206


 NEUTRAL IOC 12


 NEUTRAL
 DIRECTIONAL OC1
See page 5-207

 NEUTRAL CURRENT
 UNBALANCE 1
See page 5-212


 NEUTRAL CURRENT
 UNBALANCE 3
 NEUTRAL TOC1


NEUTRAL TOC1
FUNCTION: Disabled
Range: Disabled, Enabled

NEUTRAL TOC1 SIGNAL
SOURCE: SRC 1
Range: SRC 1, SRC 2, SRC 3, SRC 4, SRC 5, SRC 6

NEUTRAL TOC1
INPUT: Phasor
Range: Phasor, RMS

NEUTRAL TOC1
PICKUP: 1.000 pu
Range: 0.020 to 30.000 pu in steps of 0.001

NEUTRAL TOC1
CURVE: IEEE Mod Inv
Range: see Overcurrent Curve Types table

NEUTRAL TOC1
TD MULTIPLIER: 1.00
Range: 0.00 to 600.00 in steps of 0.01

NEUTRAL TOC1
RESET: Instantaneous
Range: Instantaneous, Timed

NEUTRAL TOC1 BLOCK:
Off
Range: FlexLogic operand

NEUTRAL TOC1
TARGET: Self-reset
Range: Self-reset, Latched, Disabled

NEUTRAL TOC1
EVENTS: Disabled
Range: Disabled, Enabled