1.2
SEL-387-0, -5, -6 Relay
Instruction Manual
Date Code 20170601
Introduction and Specifications
Relay Functions
Relay Functions
Figure 1.1
Functional Overview
Current Differential
Protection
The SEL-387 includes independent restrained and unrestrained current
differential elements. The restrained element has a dual-slope, variable-
percentage restraint characteristic. A separate unrestrained differential
element provides faster clearance of high-magnitude, internal faults.
SEL-387-0 Relay
The relay provides security against conditions that may cause relay
misoperation, resulting from both system and transformer events. Use the
fifth-harmonic element to prevent relay misoperation during allowable
overexcitation conditions. Even-harmonic elements (second) provide security
against inrush currents during transformer energization. In the blocking mode,
the user selects either blocking on an individual phase basis or on a common
basis, as per application and philosophy. The second- and fifth-harmonic
thresholds are set independently.
SEL-387-5 Relay and SEL-387-6 Relay
These relays also provide security against conditions that may cause relay
misoperation, resulting from both system and transformer events. Use the
fifth-harmonic element to prevent relay misoperation during allowable
overexcitation conditions. Even-harmonic elements (second and fourth
∑
3
51
P
G
3
3
Combined
67G
1
3
Autotransformer
87
50
P
G
Q
51
P
G
Q
Overcurrent
- Phase
- Ground
- Neg. Seq.
Time Overcurrent
- Phase
- Ground
- Neg. Seq.
50
P
G
Q
51
P
G
Q
Overcurrent
- Phase
- Ground
- Neg. Seq.
Time Overcurrent
- Phase
- Ground
- Neg. Seq.
50
P
G
Q
51
P
G
Q
50
P
G
Q
51
P
G
Q
Overcurrent
- Phase
- Ground
- Neg. Seq.
Time Overcurrent
- Phase
- Ground
- Neg. Seq.
- Phase
Overcurrent
- Ground
- Neg. Seq.
Time Overcurrent
- Phase
- Ground
- Neg. Seq.
52
52
52
Phase, Ground, Neg. Seq.,
Differential, and Harmonic Metering
Restrained and
Unrestrained Differential Elements
Second- and Fifth-
Harmonic Blocking
CT and Transformer
Connection Compensation
Remote and
Local Control Switches
Restricted Earth
Fault (REF) (if the fourth
winding is not used in 87)
ASCII, Binary,
Distributed Port Switch, and
DNP3 Slave Communications
Event Reports and
Sequential Events Recorder
Breaker Wear, Station
Battery, and Thermal Monitors
SEL
OGIC
®
Control Equations
52
Temperature Measurement
(SEL-387-5 and SEL-387-6 Relays)
Summary of Contents for SEL-387-0
Page 6: ...This page intentionally left blank ...
Page 12: ...This page intentionally left blank ...
Page 50: ...This page intentionally left blank ...
Page 200: ...This page intentionally left blank ...
Page 248: ...This page intentionally left blank ...
Page 380: ...This page intentionally left blank ...
Page 422: ...This page intentionally left blank ...
Page 440: ...This page intentionally left blank ...
Page 458: ...This page intentionally left blank ...
Page 516: ...This page intentionally left blank ...