Schweitzer Engineering Laboratories SEL-787-2 - Page 2

SEL-787-2, -3, -4 Data Sheet Schweitzer Engineering Laboratories, Inc.
2
Major Features and Benefits
The SEL-787 Transformer Protection Relay provides unsurpassed protection, integration, and control features in a
flexible, compact, and cost-effective package. The SEL-787 offers an extensive variety of protection features, depending
on the model and options selected. In this document, SEL-787 refers to all the models in Table 1. For protection func-
tions specific to a given MOT, the relay is referred to as SEL-787-4X, SEL-787-3E, SEL-787-3S, SEL-787-2X,
SEL-787-21, or SEL-787-2E explicitly, where needed. Table 2 shows the protection features available across models.
Table 1 Current (ACI) and Voltage (AVI) Card Selection for SEL-787 Models
Model Description/Application
Slot Z Card
(MOT Digits)
Slot Z Inputs
Slot E Card
(MOT Digits)
Slot E Inputs
787-2X 2 Winding/Terminal Current Differential 6ACI
(81, 82, 85)
IAW1, IBW1, ICW1,
IAW2, IBW2, ICW2
787-21 2 Winding/Terminal Current Differential
1 Neutral Current Input
6ACI
(81, 82, 85)
IAW1, IBW1, ICW1,
IAW2, IBW2, ICW2
1ACI
(A6, A7)
IN
787-2E 2 Winding/Terminal Current Differential
1 Neutral Current Input
3 Voltage Inputs (Phase)
6ACI
(81, 82, 85)
IAW1, IBW1, ICW1,
IAW2, IBW2, ICW2
1ACI/3AVI
(78, 79)
IN, VA, VB, VC
787-3E 3 Winding/Terminal Current Differential
1 Neutral Current Input
3 Voltage Inputs (Phase)
6ACI
(81, 82, 85)
IAW1, IBW1, ICW1,
IAW2, IBW2, ICW2
4ACI/3AVI
(72, 73, 76, 77)
IAW3, IBW3,
ICW3, IN, VA,
VB, VC
787-3S 3 Winding/Terminal Current Differential
3 Voltage Inputs (Phase)
1 Voltage Input (Vsync or Vbat)
6ACI
(81, 82, 85)
IAW1, IBW1, ICW1,
IAW2, IBW2, ICW2
3ACI/4AVI
(71, 75)
IAW3, IBW3,
ICW3, VS/VBAT,
VA, VB, VC
787-4X 4 Winding/Terminal Current Differential 6 ACI
(81, 82, 85)
IAW1, IBW1, ICW1,
IAW2, IBW2, ICW2
6ACI
(A1, A2, A5)
IAW3, IBW3,
ICW3, IAW4,
IBW4, ICW4
Table 2 SEL-787 Protection Elements (Sheet 1 of 2)
Protection Elements
2 Windings
2 Windings With
IN Channel
2 Windings With
IN Channel and
3-Phase Voltages
3 Windings With
IN Channel and
3-Phase Voltages
3 Windings With
VS/VBAT Channel and
3-Phase Voltages
4 Windings
SEL-787-2X SEL-787-21 SEL-787-2E SEL-787-3E SEL-787-3S
SEL-787-4X
87Phase Differential XXXXXX
REF Restricted Earth Fault (REF) X
a
X
a
X
a
X
a
X
a
50PPhase Overcurrent XXXXXX
50Q Neg.-Seq. Overcurrent X X X X X X
50GGround Overcurrent XXXXXX
50N Neutral Overcurrent X X X
51PPhase Time-Overcurrent XXXXXX
51Q Neg.-Seq. Time-Overcurrent X X X X X X
51GGround Time-OvercurrentXXXXXX
51PC Combined Winding Phase
Time-Overcurrent
X X X
51GC Combined Winding Ground
Time-Overcurrent
XXX