You are welcome. So far as my knowledge is concerned there is no effective thumb rule for calculation of IR value. For a new 132KV PT it should be as high as possible. But for older one it should be how? In few cases IR values of such PT were between pry. to earth 40 to 50 mega ohm and Secy. to Earth were only, 5 to 10 megaohm.And they were running smoothly. Experience will act accordingly. Thank you.
Thank you so much sir, today I tested 132kV/110V CVT which is made by Alstom and manufacturing year is 2012. and it is not charged so far from 2012. the insulation resistance we obtain as primary to earth - 374 Giga ohm, primary to core 1 -112 Giga ohm, primary to core 2 -38.4 Gohm, core 1 to earth is 2.14 Giga ohm, core 2 to earth -5.7 Gohm, core 1 to core 2.23 Gohm............. Sir how can I make a conclusion of this?? Please reply...
The n terminal usually has thin wire with poor insulation, if we apply 5kV at HV terminal while we perform the primary to body or primary to sec test wont we stress or damage the insulation of wire of N terminal?
you are most welcome. Sufficient insulation is provided at Primary side to withstand 5KV voltage. When the fuse at primary side neutral opened accidentally then full primary voltage appeared at the N- terminal. Thank you for watching the video and commenting on it.
@@electricalpassionatebut we don’t put fuse in neutral at primary side, we install fuses at secondary windings only.I mean the wire that ends at N terminal on the secondary box has small cross sectional area, so can it withstand the 5kv dc volt on insulation resistance test?
@@konstantinostheo2911 On that case, you must have seen a Link and the Link is connected with the body/tank. When you will perform the IR test you have to open that link. Otherwise, you will get no result. Again a 132 KV or 33KV PT has provided sufficient insulation and you can use 5KV for testing the PT easily.So far as the Secondary winding is concerned, you must use 500Volt. Thank you.
@@electricalpassionate when you megger it, it willbe like LG fault. But when you connect it with system ac, it wouldn't be a fault. Ok. Don't disconnect when in service. Thanks.
Very informative video 🙏🙏🙏🙏
You are welcome. Thank you for watching the video. Please watch other videos on this channel. ❤
Super sir.. your video thank you
You are welcome. Please keep watching. Thanks❤
Battery impedance test video
You are welcome. I am trying.Please keep watching. Thank you.
@@electricalpassionate ok sir
Sir , in 132kV/110V PT what should be the insulation resistance value??
Primary to earh , primary to core-1 , core-1 to earth????.... please reply
You are welcome. So far as my knowledge is concerned there is no effective thumb rule for calculation of IR value. For a new 132KV PT it should be as high as possible. But for older one it should be how? In few cases IR values of such PT were between pry. to earth 40 to 50 mega ohm and Secy. to Earth were only, 5 to 10 megaohm.And they were running smoothly. Experience will act accordingly. Thank you.
Thank you so much sir, today I tested 132kV/110V CVT which is made by Alstom and manufacturing year is 2012. and it is not charged so far from 2012. the insulation resistance we obtain as primary to earth - 374 Giga ohm, primary to core 1 -112 Giga ohm, primary to core 2 -38.4 Gohm, core 1 to earth is 2.14 Giga ohm, core 2 to earth -5.7 Gohm, core 1 to core 2.23 Gohm.............
Sir how can I make a conclusion of this?? Please reply...
@@ElectricalDot8704 IR values are good enough.If other parameters are good then it can be put into service. Sorry for belated reply. Thank you.
@@electricalpassionate thank you sir 🙏
The n terminal usually has thin wire with poor insulation, if we apply 5kV at HV terminal while we perform the primary to body or primary to sec test wont we stress or damage the insulation of wire of N terminal?
you are most welcome. Sufficient insulation is provided at Primary side to withstand 5KV voltage. When the fuse at primary side neutral opened accidentally then full primary voltage appeared at the N- terminal. Thank you for watching the video and commenting on it.
@@electricalpassionatebut we don’t put fuse in neutral at primary side, we install fuses at secondary windings only.I mean the wire that ends at N terminal on the secondary box has small cross sectional area, so can it withstand the 5kv dc volt on insulation resistance test?
@@konstantinostheo2911 On that case, you must have seen a Link and the Link is connected with the body/tank. When you will perform the IR test you have to open that link. Otherwise, you will get no result. Again a 132 KV or 33KV PT has provided sufficient insulation and you can use 5KV for testing the PT easily.So far as the Secondary winding is concerned, you must use 500Volt. Thank you.
Could you pls add (slid/pdf) file for u. Lecture....
You are welcome. Sorry. No such provision.Thanks.
sir we are creating lg fault
Agree. Thank you.
@@electricalpassionate when you megger it, it willbe like LG fault. But when you connect it with system ac, it wouldn't be a fault. Ok. Don't disconnect when in service. Thanks.