MAINTENANCE MANUAL 1B170K17 FOUR SHOT AUTO RECLOSE RELAY

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1 Sheet 1 of 9 MAINTENANCE MANUAL 1B170K17 FOUR SHOT AUTO RECLOSE RELAY The Maintenance Manual is to be read in conunction with Product/Test Manual

2 Sheet 2 of 9 INDEX 1. FULL DESCRIPTION OF OPERATION 1.1 Physical Layout 1.2 Basic Operation 1.3 Power Supply 1.4 Operation Sequence 1.5 Successful Reclose Logic Sequence 1.6 CB Trip During Reclaim Time 1.7 CB Trip During Reclose Pulse 1.8 Maximum Number of Shots 1.9 Inhibit Instantaneous Protection 2. TIMING DIAGRAMS 2.1 Successful First Reclose 2.2 Trip Circuit Reclaim Time, Successful Second Reclosure 2.3 Unsuccessful First Reclosure, Successful Second Reclosure 2.4 Two Reclosures, Lockout 3. LIST OF DRAWINGS

3 Sheet 3 of 9 1. DESCRIPTION OF OPERATION Note: In the following description refer to unit Circuit Diagram for component reference and circuit configuration. 1.1 Physical Layout Most of the circuitry is located on a T-shaped printed circuit board assembly containing all adjustment and indicating componentry, all logic and relay drive circuitry and the lockout and inhibit instantaneous protection output relays. This assembly may be withdrawn to facilitate maintenance. Power supply and transient suppression components are mounted on a motherboard into which the abovementioned assembly is plugged. 1.2 Basic Operation The 1B170 is designed to provide up to four successive reclosures in an automatic circuit breaker reclosing system. Series or shunt initiate may be used to start the relay, and after a time delay of T1 seconds a 2 second reclose pulse occurs. Immediately this pulse finishes, the lockout timer is initiated. If the circuit breaker has not tripped after this interval has elapsed, the hold-in relay drops out and the recloser is completely de-energised. If the circuit breaker trips during the first reclose pulse or before the lockout timer has timed out, this timer is reset and a timing interval T2 is commenced. After this time has elapsed a 2 second reclose pulse occurs, the lockout timer being re-initiated at the end of the reclose pulse. The circuit provides up to four reclosures (the maximum selectable from one to four via a front panel switch) and incorporates an inhibit instantaneous protection relay which may be selected to operate immediately following the first, second, third or fourth reclose pulse, or may be switched out of circuit. An electromechanical counter is provided to record the progressive total number of reclose pulses. 1.3 Power Supply The electronic circuitry in this unit is powered from a simple zener diode shunt regulator comprising R38 and D14. D11 prevents damage in the case of inadvertent reverse polarity connection of the auxiliary supply, whilst TSP limits any transients at the input to a safe level. C16 maintains the 10V rail during short-term supply transients.

4 Sheet 4 of Operation Sequence i. The recloser is either series initiated with a 1.2A or greater current pulse of 40ms or longer voltage pulse. This will cause the start/hold-in relay RL4 to pick up and latch on via RL4-1 and TR10. ii. iii. iv. Decade counter MC14017 (IC2) is pulse reset by IC1-a, giving a high on IC2 decoded 0 output )pin 3). Square waves with a period determined by IC1-d oscillator setting (proportional to 1st shot reclose time T1) are gated through IC3-c, IC4-c and IC5-d to timing IC7 oscillator input (TP-Y). Time IC7 counts the pulses at TP-Y and at time out (8192 counts) its output goes low. Timer IC8 is fed from oscillator IC1-f and has a normally high output going low 2 seconds after removal of a high on the reset input (pin 6). IC4-b and IC5-b give a pulse output at TR6 in the interval between IC7 output going low and IC8 output going low. During the first reclose pulse, the decade counter IC2 is at 0 (i.e. decoded zero output [pin 3] is high). TR1 is thus switched on and current thus flows through the electromechanical counter, output relay, TR6, LED1 and TR1, all in series. D1 ensures correct output relay operation in the event of a LED or TR1, 2, 3 or 4 failure. v. IC6-a and IC6-b from a flip-flop which gates a positive-going 7.81ms pulse to TP-Z (and the decade counter IC2 clock pin 14) at the end of IC8 time-out. This pulse is half of one cycle of the 2 second output pulse timer oscillator (IC1-f) and is easily observed on an oscilloscope. The decade counter is advanced by one count on the positive-going clock edge. Coincident with the TP-Z pulse is a negative-going pulse of the same duration at TP-V. vi. The circuit breaker auxiliary contact status is interfaced via TR9. The logic output signal is taken from the emitter and is a high for CB closed and low for CB tripped. 1.5 Successful Reclose Logic Sequence - See Timing Diagram 1 i. If the circuit breaker is successfully reclosed, IC5-a goes low at the instant of reclosure, giving a high at TP-W. Immediately following the 2 second reclose pulse is the TP-V negative-going 7.81ms pulse, which will set IC6-c output (TP-X) high and IC6-d output low.

5 Sheet 5 of Successful Reclose Logic Sequence ii. IC6-d output is fed to the reset pin of lockout timer IC9 as well as one side of the INST/DEL lockout select slide switch. Either the low-going IC9 output or low-going IC6-d output is then fed to IC5-c, which controls the lockout relay. Since the reclose has been assumed to be successful, the lockout relay will not be energised. iii. At the end of IC9 time-out, TR10 will be switched off and since the circuit breaker is closed, removing the D10 0V connection the hold-in relay will drop out, totally de-energising the 1B CB Trip during Reclaim Time - See Timing Diagram 2 i. If a fault occurs whilst IC9 (the lockout timer) is still timing out, TP-W will go low giving a high at IC6-d output and resetting IC9. TP-V will be high at this stage so IC6-c output (TP-X) will go low. ii. IC2, the decade counter, will have been set to give a decoded output 1 by a positive-going 7.81ms pulse at TP-Z and coincident with the TP-V pulse as described in paragraph (vii). Thus at the completion of the two second reclose pulse, oscillator IC1-c is gated through IC3-a, IC4-c and IC5-d to the oscillator input of timer IC7. Timer IC7 commences timing as soon as TP-X goes low, at a rate determined by pot R2 (interval 2) setting. This time interval must always occur between the first re-tripping and second reclosure. A second reclosure is initiated at the completion of IC7 time-out. 3.7 CB Trip during Reclose Pulse - See Timing Diagram 3 i. If the circuit breaker is not closed at the completion of the 2 second reclose pulse and the allowable number of shots has not been reached, TP-W will be low at the completion of the reclose pulse. A 7.81ms pulse will appear at TP- X coincident with the decade counter incrementing pulse at TP-Z. IC7 will thus be reset and will now count the pulses from oscillator IC1-e having a frequency determined by pot R7 (interval 3). These pulses are gated to IC7 via IC3-d, IC1-d and IC5-d.

6 Sheet 6 of Maximum Number of Shots - See Timing Diagram 4 i. The maximum allowable number of shots is selected by SW-1. The wiper of this switch will go high at the finish of the selected number of shots (assuming all shots are unsuccessful). TP-W will go high and remain in this state irrespective of any change of circuit breaker status. TP-X will go high due to the negative going TP-V pulse and remain in this state due to TP-W being high and thus maintaining a low at IC6-a output. ii. iii. If the last shot is successful the hold-in relay will drop out after the lockout timer has timed out (as described in paragraphs (ix) and (x) ). If the last shot is unsuccessful at the completion of time-out by IC9, IC5-c output will go high and the lockout relay will be energised. TR10 will be switched off but the hold-in relay will remain energised vix D10 and the circuit breaker auxiliary repeat contact. Manual resetting of the circuit breaker will thus cause the 1B170 to fully reset (i.e. de-energise). 3.9 Inhibit Instantaneous Protection. SW-2 wiper goes high immediately after the shot number selected has been completed - e.g. if 2 is selected, RL3 is energised at the instant of completion of the second reclose pulse. TR7 and associated circuitry from a flip-flop with TR8 to hold RL3 in permanently once it has been energised.

7 Sheet 7 of 9 2. TIMING DIAGRAMS 2.1 Successful First Reclose 2.2 Trip Circuit Reclaim Time, Successful Second Reclosure

8 Sheet 8 of Unsuccessful First Reclosure, Successful Second Reclosure 2.4 Two Reclosures, Lockout

9 Sheet 9 of 9 3. LIST OF DRAWINGS Wiring Diagram 1B170K Circuit Diagram 1B170K Loading Diagram - Mother PCB Loading Diagram - Main Logic PCB Loading Diagram - Front Panel PCB Loading Diagram - Relay Mounting PCB

PRODUCT TEST MANUAL 2SY110K28 SYNCHRONISM CHECK RELAY

Sheet 1 of 7 Order Number Serial Number PRODUCT TEST MANUAL 2SY110K28 SYNCHRONISM CHECK RELAY Issue Date Level D 12/12/1996 Initial issue. Summary of changes Due to RMS continuous product improvement policy