GE D60 Instruction Manual page 282

5.6 CONTROL ELEMENTS
b) DIRECT UNDER-REACHING TRANSFER TRIP (DUTT)
PATH: SETTINGS CONTROL ELEMENTS
DUTT SCHEME
5
This scheme uses an under-reaching Zone 1 distance element to key a transfer trip signal(s) to the remote end(s), where
on receipt, the DUTT pilot scheme operates without additional protection supervision. For proper operation of the scheme
the Zone 1 phase and ground distance elements must be enabled, configured, and set per rules of distance relaying.
In single-pole tripping applications, the scheme uses local fault type identification provided by the Phase Selector together
with information received from the remote terminal(s). The latter may be coded into one, two or four bits over the communi-
cations channel.
The scheme generates output operands (
signals to the remote end(s). Choices of communications channel include remote inputs/outputs and telecommunications
interfaces. When used with telecommunications facilities the output operands should be assigned to operate output con-
tacts connected to assert the individual bits at the interface.
To make the scheme a fully operational stand-alone feature, the scheme output operands must be configured to interface
with other relay functions, output contacts in particular. Typically, the output operands should be programmed to initiate a
trip, breaker fail, and autoreclose, and drive a user-programmable LED as per user application. When used in conjunction
with the Trip Output, the scheme is pre-configured to initiate trip, breaker fail, and single-pole autoreclose actions.
• DUTT SEAL-IN DELAY: The output FlexLogic™ operand (
A seal-in time delay is applied to this operand for coping with noisy communication channels such as a power line car-
rier. The
DUTT SEAL-IN DELAY
Trip Table of the DUTT scheme, the trip operands
• DUTT NO OF COMM BITS: This setting specifies the number of bits available on the communications channel. With
only one bit available, the scheme sends the direct under-reaching transfer trip command on bit no.1 (
and) and responds to the direct trip command received on bit no. 1 (
fault type identification provided by the Phase Selector to assert the output operands
Chapter 8: Theory of Operation for details on the use of communication channels).
• DUTT RX1 through DUTT RX4: These settings allow the user to select the FlexLogic™ operands that represent the
receive signals for the scheme. Typically input contacts interfacing with a signaling system are used.
5-192
PILOT SCHEMES
DUTT SCHEME
FUNCTION: Disabled
DUTT SEAL-IN
MESSAGE
DELAY: 0.010 s
DUTT NO OF COMM
MESSAGE
BITS: 1
DUTT RX1:
MESSAGE
Off
DUTT RX2:
MESSAGE
Off
DUTT RX3:
MESSAGE
Off
DUTT RX4:
MESSAGE
Off
DUTT SCHEME TARGET:
MESSAGE
Self-Reset
DUTT SCHEME EVENTS:
MESSAGE
Disabled
through
DUTT TX1
is a minimum guaranteed duration of the
D60 Line Distance Relay
DUTT SCHEME
Range: Disabled, Enabled
Range: 0.000 to 65.535 s in steps of 0.001
Range: 1, 2, or 4
Range: FlexLogic™ operand
Range: FlexLogic™ operand
Range: FlexLogic™ operand
Range: FlexLogic™ operand
Range: Self-Reset, Latched, Disabled
Range: Disabled, Enabled
) that are used to transmit the direct under-reaching
DUTT TX4
) is produced according to the DUTT scheme logic.
DUTT OP
DUTT OP
, , and are sealed-in for the same period of time.
DUTT TRIP A B C 3P
DUTT RX1
5 SETTINGS
pulse. As this operand activates the
DUTT TX1
setting). The scheme uses only local
, , and
DUTT TRIP A B C
GE Multilin
oper-
(see
3P