Section 3: Applications And Ordering Information; Non-Pilot System; Line Measurement Techniques - ABB REL300 Instruction Manual

Section 3. APPLICATIONS AND ORDERING INFORMATION
Before energizing the relay, check jumper #3 on the Microprocessor
module for phase sequence rotation ABC or ACB. Remove jumper #3 for
system ABC rotation. Refer to Section 1.8 for ACB system.
3.1

NON-PILOT SYSTEM

The REL300 non-pilot relay system detects faults in three zones of distance, phase and
ground. Zones 1 and 2 are forward set; Zone 3 can be set to forward or reverse. There is also
a separate optional pilot zone (see Section 3.5). The fault locator can be set to indicate fault
distance in miles or kilometers.
The R-X Diagram, shown in Figure 3-1, describes the characteristics available with REL300.
Zone 1 phase and ground settings are chosen to provide substantial coverage of the protected
line without overreaching the next bus. A setting of 80% of the line impedance is typical. Faults
occurring within the reach of the Zone 1 measurement cause direct tripping without regard to
any action occurring at the remote terminal. Zone 2 settings are chosen to assure that faults
occurring on the next bus are recognized. Settings are chosen (independent of the Zone 1 set-
tings), generally to be 120 to 150% of the line impedance. Any fault occurring on the protected
line will be recognized by this Zone 2 measurement (within the fault resistance and current lim-
itations of the relaying system). Zone 2 tripping occurs with time delay (T2) or, where equipped
with pilot provisions, at high speed, subject to the constraints imposed by the pilot channel for
the particular pilot system selected. The Zone 3 measurement is directional, and may be cho-
sen to respond to forward or reverse faults. The reverse sensing option is chosen for the block-
ing system where the reverse fault carrier start function is required. It is also used in conjunction
with the T3 trip function, chosen to coordinate with adjacent terminal Zone 2 timing. The for-
ward sensing option produces time delayed backup to other devices sensing forward faults.
Blinder measurements (B1, B2, B3, B4) are available for out-of-step sensing. The inner blinder
(as a standard function) also restricts the trip zone of each of the 3-phase fault measuring units.
3.2

LINE MEASUREMENT TECHNIQUES

Line measurement techniques applied to each zone include:
• Single-Phase-To-Ground fault detection
• 3-Phase fault detection
• Phase-to-Phase fault detection
• Phase-to-Phase-to-Ground fault detection
!
WARNING
I.L. 40-385.7
3-1