Electrical Distribution Training Training for Sepam Series 20/40/80 Control and monitoring functions

Presentation Sepam series 20/4080 perform the basic control and monitoring functions required for electrical network operation and also reduces the need for auxiliary relays. Each Sepam includes the appropriate control and monitoring functions for the chosen application. In order for functions to be used, exclusive parameter setting and special wiring of the inputs and outputs are required. For easier commissioning, the functions have default settings that may be used for the most frequent applications.

Switchgear control This logic function handles all the circuit breaker closing and tripping conditions based on: breaking device status data remote control orders protection functions specific control logic scheme for each application (e.g. recloser, load shedding) In order for this function to operate, the Sepam series 80 must have the necessary logic inputs (an MES 120 module is required).

Switchgear control

Switchgear control detail of ANSI 25 control

Switchgear control Circuit breaker or contactor with tripping coil (parameter: circuit breaker)

Switchgear control Simple contactor (parameter: contactor)

Latching / acknowledgment The functions that inititate tripping may be latched individually when they are set up and may be reset according to different modes.

TC / switchgear position discrepancy This function detects discrepancies between the last remote control order received and the actual position of the circuit breaker or contactor.

Disturbance recording trigger

Switching of groups of settings There are two groups of settings, group A / group B, for the phase overcurrent, earth fault, directional phase overcurrent and directional earth fault protection functions. By switching from one group of settings to another, the protection characteristics may be adapted to suit the electrical environment of the application (change of earthing system, changeover to local power generation …).

Logic discrimination This function considerably reduces the tripping time of the circuit breakers closest to the source and may be used in closed ring networks. It applies to the the phase overcurrent 50/51, directional phase overcurrent 67, earth fault 50N/51N and directional earth fault 67N protection functions (definite time and IDMT). Blocking order Time-based discrimination Logic discrimination

Logic discrimination Blocking signals are sent during the time required to clear the fault. If the Sepam gives a tripping order, the blocking signals are interrupted after a time delay that takes into account the breaking device operating time and the protection relay reset time. This system guarantees safety in downgraded operating situations (faulty wiring or switchgear). Pilot wire test The pilot wires may be tested using the output relay test function in the SFT2841 software.

Logic discrimination Threshold assignment Threshold assignment for S80, S81 and T81 applications 1 reception and 1 send (radial network) Threshold assignment for M81, M87 and M88 applications No reception because last link in chain. Threshold assignment for S82, T82, T87, G82, G87, G88 applications 2 receptions and 2 sends (ring network, 2 parallel incomers, etc.)

Logic discrimination / 1 reception and 1 send

Logic discrimination / radial network + -- 1A 1kA inst 1A 1kA 0.2s 1B 1kA 0.5s Downstream Sepam Upstream Sepam 1 No fault / initial phase

Logic discrimination / radial network + -- 1A 1kA inst 1A 1kA 0.2s 1B 1kA 0.5s Downstream Sepam Upstream Sepam 1 Appearance of fault Blocking signal Case 1

Logic discrimination / radial network Blocking signal during opening + -- 1A 1kA inst 1A 1kA 0.2s 1B 1kA 0.5s Downstream Sepam Upstream Sepam 1 Tripping order TRIP Case 1

Logic discrimination / radial network + -- 1A 1kA inst 1A 1kA 0.2s 1B 1kA 0.5s Downstream Sepam Upstream Sepam 1 Appearance of fault Blocking signal Case 2

Logic discrimination / radial network Blocking signal during opening + -- 1A 1kA inst 1A 1kA 0.2s 1B 1kA 0.5s Downstream Sepam Upstream Sepam 1 Tripping order but problem during opening TRIP Case 2

Logic discrimination / radial network + -- 1A 1kA inst 1A 1kA 0.2s 1B 1kA 0.5s Downstream Sepam Upstream Sepam 1 Blocking signal inhibition and upstream opening Case 2 TRIP

Logic discrimination / radial network + -- 1A 1kA inst 1A 1kA 0.2s 1B 1kA 0.5s Downstream Sepam Upstream Sepam 1 Appearance of fault Blocking signal Case 3

Logic discrimination / radial network Blocking signal during opening + -- 1A 1kA inst 1A 1kA 0.2s 1B 1kA 0.5s Downstream Sepam Upstream Sepam 1 Tripping order but problem during opening TRIP Case 3

Logic discrimination / radial network + -- 1A 1kA inst 1A 1kA 0.2s 1B 1kA 0.5s Downstream Sepam Upstream Sepam 1 Inhibition problem Case 3 TRIP

Logic discrimination / radial network + -- 1A 1kA inst 1A 1kA 0.2s 1B 1kA 0.5s Downstream Sepam Upstream Sepam 1 Backup threshold order Case 3 TRIP

Logic discrimination / closed ring networks Closed ring networks may be protected by Sepam S82 or T82, which include the following functions: directional phase (67) and earth fault (67N) protection, with 2 units of each: one unit to detect faults in the "line" direction one unit to detect faults in the "busbar" direction use of 2 discrimination types: receipt of 2 blocking signals, to block the direction protection functions according to the detection direction Sending of 2 blocking signals, according to the detected fault direction

Logic discrimination / closed ring networks With the combination of directional protection functions and logic discrimination, the faulty section may be isolated with a minimal delay by tripping of the circuit breakers on either side of the fault. Blocking signals are initiated by both protection functions 67 and 67N. Priority is given to 67: when 67 and 67N detect faults in opposite directions at the same time, the blocking signal sent is determined by the direction of the fault detected by protection 67. The instantaneous output of protection function 67, activated at 80% of the Is threshold, is used to send blocking signals. This avoids uncertainty when the fault current is close to the Is threshold.