GE350 Feeder Protection System

the equipment

Contact inputs

External contacts can be connected to the relay’s ten (10) digital inputs. These contacts are 

wet only.

The inputs can be programmed to different thresholds depending on the DC voltage (17, 

33, 84, 166).

CAUTION: Ensure correct polarity on contact input connections and do not connect any contact 

input circuits to ground or else relay hardware may be damaged.

A wet contact has one side connected to the positive terminal of an external DC power 

supply. The other side of this contact is connected to the required contact input terminal. In 

addition, the negative side of the external source must be connected to the relay’s DC 

negative rail at Terminal C11. The maximum external source voltage for this arrangement 

is 300 V DC.

Trip and Close output relays

The 350 relay is equipped with seven electromechanical output relays: two special relays 

designed for Breaker trip and close (Relay 1 “Trip”, Relay 2 “Close”), four general purpose 

relays (Auxiliary Relays 3 to 6), and a Critical Failure relay. The special purpose relays have 

fixed operating characteristics and the general purpose relays can be configured by the 

user.

Operation of the Trip and Close output relays is designed to be controlled by the state of 

the circuit breaker as monitored by a 52a or 52b contact.

• The Trip and Close relays reset after the breaker is detected in a state corresponding 

to the command. When a relay feature sends a command to one of these special 

relays, it will remain operational until the requested change of breaker state is 

confirmed by a breaker auxiliary contact and the initiating condition has reset.

• If the initiating feature resets, but the breaker does not change state, the output relay 

will be reset after a default interval of 2 seconds.

• If neither of the breaker auxiliary contacts, 52a nor 52b, is programmed to a contact 

input, the Trip Relay is de-energized after either the delay programmed in the Breaker 

Failure feature, or a default interval of 100 ms after the initiating input resets. The 

Close Relay is de-energized after 200 ms.

• If a delay is programmed for the Trip or Close contact seal-in time, then this delay is 

added to the reset time. Note that the default setting for the seal-in time is 40 ms.

Breaker monitoring (Trip and Close coil monitoring) is performed by a built-in voltage 

monitor on Form A output relays: #1 Trip, and #2 Close. The voltage monitor is connected 

across each of the two Form A contacts, and the relay effectively detects healthy current 

through the circuit. In order to do this, an external jumper must be connected between 

terminals A2 and A3 for Trip coil monitoring, or/and B4, and B5 for Close coil monitoring.

As long as the current through the Voltage Monitor is above the threshold of the trickle 

currents (see Technical Specification for Form A output relays), the circuit integrity for the 

Trip (Close) coil is effectively normal. If the Trip (Close) coil circuit gets disconnected, or if in 

general a high resistance is detected in the circuitry, a Trip (Close) alarm will be set and the 

“ALARM” and “MAINTENANCE” LEDs will be on.

Example 1: The figures below show the two different connections of the breaker trip (close) 

coil to the relay’s trip output #1 terminals (output #2 Close coil monitoring) for both no 

voltage monitoring and voltage monitoring of the trip (close) circuit integrity.

NOTE

NOTE: To monitor the trip coil circuit integrity, use the relay terminals A2 and B3 to connect the 

Trip coil, and provide a jumper between terminals A2 (optional voltage) and A3.

IRIG-B

IRIG-B is a standard time code format that allows time stamping of events to be 

synchronized among connected devices within 1 millisecond. The IRIG time code formats 

are serial, width-modulated codes which can be either DC level shift or amplitude 

modulated (AM) form. The type of form is auto-detected by the 350 relay. Third party 

equipment is available for generating the IRIG-B signal; this equipment may use a GPS 

satellite system to obtain the time reference so that devices at different geographic 

locations can also be synchronized.

The uncovered communications cable shield connected to the common terminal should 

not exceed 1” (2.5 cm) for proper EMC shielding of the communications cable.

350 Feeder Protection System

Chapter 3: Interfaces

Interfaces

There are two methods of interfacing with the 350 Feeder Protection System.

• Interfacing via the relay keypad and display.

• Interfacing via the EnerVista 3 Series Setup software.

This section provides an overview of the interfacing methods available with the 350 using 

the relay control panels and EnerVista 3 Series Setup software. For additional details on 

interface parameters (for example, settings, actual values, etc.), refer to the individual 

chapters.