Schweitzer Engineering Laboratories SEL-351A - Figure 3.15 A-Phase Time-Overcurrent Element 51 AT (with Directional Control Option in SEL-351 A); Figure 3.16 B-Phase Time-Overcurrent Element 51 BT (with Directional Control Option in SEL-351 A)

3.21
Date Code 20080213 Instruction Manual SEL-351A Relay
Overcurrent, Voltage, Synchronism Check, and Frequency Elements
Time-Overcurrent Elements
q From Figure 4.24. Directional Control logic input is constantly asserted to
logical 1 in SEL-351A-1.
Figure 3.15 A-Phase Time-Overcurrent Element 51AT (With Directional
Control Option in SEL-351A)
q From Figure 4.24. Directional Control logic input is constantly asserted to
logical 1 in SEL-351A-1.
Figure 3.16 B-Phase Time-Overcurrent Element 51BT (With Directional
Control Option in SEL-351A)
51AP
I
A
Setting
51ATC
Torque Control Switch
Directional Control
(asserted to logical 1
continuously if E32 = N)
q
(Level 1)
SEL
OGIC
Torque Control
51AT A-Phase
Time-Overcurrent Element
Curve Timing and Reset Timing
Settings
51AP Pickup
51AC Curve Type
51ATD Time Dial
51ARS Electromechanical
Reset? (Y/N)
Pickup
Curve
Timeout
Reset
51A
51AR
51AT
Torque Control
TCA State Switch Position
Logical 1 Closed
Logical 0 Open
Logic Point TCA Controls the Torque Control Switch
Setting
51ARS = Reset Timing
Y Electromechanical
N 1 Cycle
TCA
Relay
Word
Bits
SELOGIC
Setting
51BP
I
B
Setting
51BTC
Torque Control Switch
Directional Control
(asserted to logical 1
continuously if E32 = N)
q
(Level 1)
SEL
OGIC
Torque Control
51BT B-Phase
Time-Overcurrent Element
Curve Timing and Reset Timing
Settings
51BP Pickup
51BC Curve Type
51BTD Time Dial
51BRS Electromechanical
Reset? (Y/N)
Pickup
Curve
Timeout
Reset
51B
51BR
51BT
Torque Control
TCB State Switch Position
Logical 1 Closed
Logical 0 Open
Logic Point TCB Controls the Torque Control Switch
Setting
51BRS = Reset Timing
Y Electromechanical
N 1 Cycle
TCB
Relay
Word
Bits
SELOGIC
Setting
Courtesy of NationalSwitchgear.com