MiCOM P127

MiCOM P127 1. Description: MiCOM P127 Directional/Non Directional Earth Fault Relay. 2. Application: The MiCOM P127 feeder protection relays measure and protect against the Three Phase Over Current, Thermal Overload, Under Current, Negative Phase Sequence Over Current, Directional/Non directional Earth fault, and Watt metric earth fault protection. Extra functions are Broken Conductor Detection, Watchdog, and Residual over Voltage Protection. 3. Test Requirements: 3.1. General/Visual inspection. 3.2. Electrical tests. 3.2.1.Measurement Test 3.2.2.Time Delayed Phase over current. 3.2.3.Earth Fault. 3.2.4.Negative Phase current. 3.2.5.Thermal over load. 3.2.6.Undercurrent. 3.2.7.Residual Over Voltage. 4. Equipment Required: 4.1. Ponovo kit. 4.2. Computer with required configuration and software. 5. Relay Terminals: 5.1. 2 & 6 : Relay Tripping Terminals. 5.2. 33 & 34 : Auxiliary D.C Supply. (33 +ve), (34 -ve). 5.3. 41-42 : A Phase Current input terminals (5 amp C.T). 5.4. 43-44 : B Phase Current input terminals (5 amp C.T). 5.5. 45-46 : C Phase Current input terminals (5 amp C.T). 5.6. 47-48 : Earth fault terminals for 5A CT. 5.7. 49-50 : A Phase Current input terminals (1 amp C.T). 5.8. 51-52 : B Phase Current input terminals (1 amp C.T). 5.9. 53-54 : C Phase Current input terminals (1 amps C.T). 5.10. 55-56 : Earth fault terminals for 1A CT. 5.11. 69-70 : A Phase Potential terminals. 5.12. 71-72 : B Phase Potential terminals. 5.13. 73-74 : Potential terminals (Open Delta). 6. General / Visual inspection: Inspect the physical condition of the relay. Confirm that there is no damage in the relay. In case of damage is minor in nature and does not affect the performance of the relay report to the customer representative and proceed for testing. If the damage is major, report to the customer and set it aside6.1 General inspection: Wipe away any dust that has collected on the on the relay. After the visual inspection clean the relay for dust and any foreign material using cloth and brush. Note down the setting on the relay as detailed bellow: Press “↓” key, then press “→” key to go “protection group G1”. Press “↓” key again & note down settings of first function. Then press “→” key for the next function & repeat above step. Repeat the above steps & note down all the settings values one after another until all functions are over. Caution: Don’t Press ‘Enter’ key (middle key) at the time of writing service settings. The settings values will change if you press the enter key. 7. Measurement test: 7.1. Inject a nominal current less than the protection settings and note down the currents in each phase. 7.2. Calculate the value as bellow. 7.3. Compare practical value if it is within +/- 10% of the calculated then the relay is ok.

8. Phase over current (I>): 8.1. Connect 33 & 34 of relay terminals to D.C auxiliary voltage terminals to positive and negative terminals respectively 8.2. Connect current terminals (ABC) of Ponovo kit to relay current terminals 49, 51, 53 and N to 50, 52, and 54 as per connection diagram enclosed. 8.3. Connect the tripping terminal 2 & 6 of relay to binary input terminals of ponovo kit. 8.4. Here there are two curve settings (In this function there is 3 stages of protection: I>, I>>, I>>>.This first stage is use for both IDMT and DMT curve but the 2nd & 3rd stage is use for only DMT curve). 8.4.1.IDMT curve (toC.1/2/3). 8.4.2.DMT curve (toC0). 8.5. Calculations 8.5.1.For IDMT curve. (I>) see the curve toC (SI/VI/EI) Service setting will be like this “I> = K In” (where In= Secondary of CT, K= setting value). Calculate minimum trip current I and trip time t from bellow formulae: Where In= Secondary of CT, K= setting value. Where t = Operation time β = Constant M= I/Is Ι = Injected current T = Time setting Ιs = Current threshold setting α = Constant Curve Description Standard Inverse Very Inverse Extremely Inverse

Standard IEC IEC IEC

β Constant 0.14 13.5 80

α Constant 0.02 1 2

8.5.2.For DMT curve. (I>) see the curve toC (SI/VI/EI) Service setting will be like this “I> = K In” (where In= Secondary of CT, K= setting value). Calculate minimum trip current I from bellow formulae: Where In= Secondary of CT, K= setting value Trip time will be same as in service setting. 8.6. Now inject current 2, 5, 10 times of above calculated minimum trip current if it is IDMT curve and same current if it is DMT curve and note down respective trip times. 8.7. If the practical trip time is +/- 10% of the calculated then relay is ok. 8.8. Reset the relay. 9. Earth Fault (Io>): 9.1. Connect 33 & 34 of relay terminals to D.C auxiliary voltage terminals to positive and negative terminals respectively 9.2. Connect current terminals (A) of Ponovo kit to relay current terminal 55 and N to 56 as per connection diagram enclosed. 9.3. Connect the tripping terminal 2 & 6 of relay to binary input terminals of ponovo kit 23&24 /13&14. 9.4. Here there are two curve settings (In this function there is 3 stages of protection: I>, I>>, I>>>.This first stage is use for both IDMT and DMT curve but the 2nd & 3rd stage is use for only DMT curve). 9.4.1.IDMT curve (toC.1/2/3). 9.4.2.DMT curve (toC0). 9.5. Calculations 9.5.1.For IDMT curve. (I>) see the curve toC (SI/VI/EI) Service setting will be like this “I> = K In” (where In= Secondary of CT, K= setting value). Calculate minimum trip current I and trip time t from bellow formulae:

Where In= Secondary of CT, K= setting value.

Where t = Operation time β = Constant M= I/Is Ι = Injected current T = Time setting Ιs = Current threshold setting α = Constant Curve Description Standard Inverse Very Inverse Extremely Inverse

Standard IEC IEC IEC

β Constant 0.14 13.5 80

α Constant 0.02 1 2

9.5.2.For DMT curve. Service setting will be like this “I> = K In” (where In= Secondary of CT, K= setting value). Calculate minimum trip current I from bellow formulae: Where In= Secondary of CT, K= setting value 9.6. Trip time will be same as in service setting. 9.7. Now inject current 2, 5, 10 times of above calculated minimum trip current if it is IDMT curve and same current if it is DMT curve and note down respective trip times. 9.8. If the practical trip time is +/- 10% of the calculated then relay is ok. 9.9. Reset the relay. 10. Negative Phase Sequence test: 10.1. Connect 33 & 34 of relay terminals to D.C auxiliary voltage terminals to positive and negative terminals respectively. 10.2. Connect current terminals (ABC) of Ponovo kit to relay current terminals 49, 51, 53 and N to 50, 52, and 54 as per connection diagram enclosed. 10.3. Connect the tripping terminal 2 & 6 of relay to binary input terminals of ponovo kit. 10.4. Inject the current less that service setting. 10.5. Now inject the current as of service setting but in negative/reverse phase. 10.6. Compare practical value if it is within +/- 10% of the setting value then the relay is ok. 10.7. Go record menu & see the fault condition. 10.8. Press ‘↑’ key, go to clear all alarms and press ‘C’ key. 11. Thermal over Load: 11.1. Connect 33 & 34 of relay terminals to D.C auxiliary voltage terminals to positive and negative terminals respectively. 11.2. Connect current terminals (ABC) of Ponovo kit to relay current terminals 49, 51, 53 and N to 50, 52, and 54 as per connection diagram enclosed. 11.3. Connect the tripping terminal 2 & 6 of relay to binary input terminals of ponovo kit. 11.4. Inject current value as worked out from the formulae given bellow. I = current to be injected, ‘Iθ>’ = Thermal setting as noted, ‘In’ = CT secondary current, K = no of times to be injected assume K=5 until advised by customer. Ex: If relay setting current is 1 amp, CT ratio is X/1, then inject current 5Amps (1*1*5). Calculate the tripping time as bellow

11.5. Compare practical value if it is within +/- 10% of the calculated then the relay is ok.

11.6. Reset the relay by following bellow steps 11.7. When the tripping occurred the tripping led will glow & show the cause of fault. 11.8. Read the fault condition by pressing the ‘read’ key. 11.9. Go to process menu by pressing down arrow and right arrow key. 11.10. Press down arrow key and observe “% I FLC” value which indicates % thermal content. 11.11. Press down arrow key again then press “C” key to clear the thermal content. At the time of setting it alarm light goes off. 12. Under Current: 12.1. Connect 33 & 34 of relay terminals to D.C auxiliary voltage terminals to positive and negative terminals respectively. 12.2. Connect current terminals (ABC) of Ponovo kit to relay current terminals 49, 51, 53 and N to 50, 52, and 54 as per connection diagram enclosed. 12.3. Connect the tripping terminal 2 & 6 of relay to binary input terminals of ponovo kit. Service setting will be like this “I> = K In” (where In= Secondary of CT, K= setting value). Calculate minimum trip current I from bellow formulae: 12.4. 12.5. 12.6. 12.7.

Where In= Secondary of CT, K= setting value Trip time will be same as in service setting. Now inject current slightly less than the above calculated minimum trip current note down trip time. If the practical trip time is +/- 10% of the calculated then relay is ok. Reset the relay.

13. Residual Over Voltage: 13.1. Connect 33 & 34 of relay terminals to D.C auxiliary voltage terminals to positive and negative terminals respectively. 13.2. Connect Voltage terminals (A) of Ponovo kit to relay current terminals 73 and N to 74 as per connection diagram enclosed. 13.3. Connect the tripping terminal 2 & 6 of relay to binary input terminals of ponovo kit. Service setting will be like this “I> = K In” (where In= Secondary of CT, K= setting value). Calculate minimum trip voltage VZ from bellow formulae: Where Vn= Secondary of CT, K= setting value 14. Reset the relay.  When the tripping occurred the tripping led will glow & show the cause of fault.  Read the fault condition by pressing the “read” key.  Press the “read” key 3 times then it asks for “reset the alarm”.  Press “C” key for reset then go for another phase test. 15. Result: Record the result in P127 test format.