Protection Relay Setting Calculation for MV Motor Feeder Relays

Performed relay setting calculation for the following relays:
- Excessive Start Time Protection Relay (48)
- Thermal Overload Protection Relay (49)
- Negative Phase Sequence Protection Relay (46)
- Stall Detection Protection Relay (51LR)
- Phase Under Voltage Protection Relay (27)
- Phase Over Voltage Protection Relay (59)
- Phase Time Delay Overcurrent Protection Relay (51)
- Ground Time Delay Overcurrent Protection Relay (51G)
- Start Number Protection Relay (66)
- Loss of Load Protection Relay (37)
- Sonde Temperature in Windings

[@tuna6423]

Hi Julius, I am thinking that 24:15 Earth fault protection If it is set only 2 value i.e., threshold and definite time, it should be called as 50G not 51G Unless you select IDMT Characteristic e.g., NINV, VINV or EINV Normal/Very/Extremely Inverse respectively and set time multiplier this will be 51G

[@Mukhaizna]

great video, thanks for sharing. might be a good idea to include the motor inertia, mechanical load details, run a simulation using Digsilent power factory , and see the performance of the protection setting under various operating scenarios.

[@shihabahmedalkatrani3050]

Thanks 🙏

[@pinoymaster1067]

nice video tutorial sir

[@aliamoor1541]

Thanks a lot for this great video but how we set IDMT RELAY I mean 51relay second stage

[@juliussalutan8006]

IDMT relay second stage is not being envisage for MV motor feeder relay

[@ImranKhan-nu6xw]

Thanks for sharing the valuable information Kindly prepare a vedio on radial feeder setting for distribution system of load 7000kva, full load current 400 amp ,bus voltage 11kv ,CT ratio 400/5 ,low settings,high setting i.e I>,I>>& I>>>

[@juliussalutan8006]

I'll consider your request on my future videos, welcome

[@rjleal]

Hello, great video. Where did you get the settings that you show here? For example, the 80% of the short circuit current? Is there any standard for this? Thank you

[@juliussalutan8006]

I think for the 80%, it is related to the setting of undervoltage relay. For industry practice, undervoltage relay setting is being set between 70 % to 80% of the nominal voltage

[@yassineallouche9844]

And for Time of 70% WE Can let 3sec??​@@juliussalutan8006

[@reyyanez6705]

Sir, yung SONDE temperature protection, Anong temperature element po gamit nun same lang po ba sa RTD Pt.?

[@juliussalutan8006]

Yes sir, RTD PT100