RMU fuse operating trip mechanism
ฝัง
- เผยแพร่เมื่อ 11 ธ.ค. 2015
- I did some fuse trip tests on an old oil filled RMU at the depot.
The fuses operated at 3 times the nominal current but the striker pin didn't. Main reason was that the test voltage of 24 - 40 Volts at 100 Amps wasn't high enough to trigger the striker device. I activated the striker cartridge mechanism by means of a 150 Volts transformer.
Normally these fuses run at 6.6 or 11 kV and when they open circuit because of a fault or overload the striker operates within a fraction of a second. - วิทยาศาสตร์และเทคโนโลยี
Great vid! Man I would love to have one of those fuses! This certainly clears a lot of questions I've had about how these work and what the striker does
Really awesome of your workplace to allow you to record such videos. Thanks for the upload!
+Marcell Bernát We want to use this for a training video for new trainees as well.
Great video. I look forward to the next
great work
Awesome !! Thumbs up :D
Alex
Rodalco my man i found 3 13kV siba fuses 36amps each in an abandoned wind turbine that was fallen on the ground. Also found three 690 volt NON PCB capacitors from siemens. Nice
Aside from debris and moisture, anytime an arc occurs in an oil cooling medium Carbon is created. You gotta filter that stuff out to keep maximum dielectric.
+paul larson
Yep!
De-energize Spider!
thank you well done
now thats what i call fuses! very nice you want to make a training video ....i would watch it :)
having fun at work
Good video and thank for you video. I have one issue with my old cubicle RM6 fuse function. between rm6 and transformer , I have one control panel. if I want to trip on upstream of transformer from RM6 cubicle fuse how could I do ? I hope you can help me. thank you in advance!
Thank you. Great video.
Soooo many people do not understand the danger of dropping a single phase instead of all three.
Burned out motors. UPS and stand by generators with only single phase power loss detection. Power partially goes out but the standby electric generator or UPS system never detects it. Why? Phase B tripped but the sensing wire is on Phase A. 1/3 chance of detection. 2/3 chance of no detection. "The odd are never in our favor" - Mocking Jay movie.
Thanks for the example video. "Do not try this at home" :)
Interesting - I would have thought that the pin would simply be spring loaded, being held in by the fuse element, so that there would be no way to have an open fuse element without the pin being released. If the fuse element is too delicate for this, there could be a lever mechanism to provide mechanical advantage, or even a cam mechanism which takes only a tiny force to hold it in the normal position but once released would allow the pin to come out, similar to a compound bow.
Are you saying that the pin is ejected by a completely separate mechanism from the fuse element? Is it a magnetic device like a solenoid?
+Sean Breheny If I am right, there is a 'gunpowder' charge which fires the pin out with enough force to operate the tripping mechanism. The charge is triggered by the voltage potential across the blown fuse.
I am sure RODALCO2007 will correct me if I am wrong (I haven't worked with HV switchgear for a number of years now!)
+Paul Roberts 100 % correct there is a gunpowder charge within the fuse cartridge. You can smell the Sulphur, after the trigger. And the charge is triggered by the Voltage potential across the blown fuse. 40 Volts AC was not enough for a reliable trigger charge.
+Sean Breheny I will do an autopsy video on one of those fuses.
+RODALCO2007 I look forward to it! Do you know how the potential triggers the charge? Some kind of heating element?
bubbles stopped wen de energized
Great vid. I only get to play with SF6 RMU's and CB's. Any silver in those fuses? ;)
how often do you get a call to replace a fuse like that ?
+ljmike1204 Not that often. Fuses more often blow when a cable fault happens, when struck by a digger or directional drill. Sometimes when a transformer is severely overloaded.
okay cool
base on what you chose 25A fuse for e.g MCCB rate or transformer KVA or there is a list or something else, because some times fuse will completely burn and we cannot find any information on the old one.
It depends upon the size of the transformer(s) connected to the circuit. Roughly 8 to 10 Amps per 100 kVA @ 11 kV. So the 25 Amp HRC fuse would have been on a 200 to 300 kVA transformer circuit.
@@RODALCO2007 Thanks for your efforts and your quick answer
I wonder if people have ever put the fuses in the wrong way round? So that the pin doesnt de energize the other phases.
+TheColinputer Yes it happens, I nearly did on this video. Well it will be the same as with the drop out fuses, A TX will remain energized at 2 phases.
+RODALCO2007 Hopefully with one on the wrong way the others will have enough unbalanced load to trip one, in the right way round, before the transformer overheats too badly. Would have to be a pretty fast cable fault to take all 3 out though. I always found that only 2 out of 3 3 phase fuses would blow on a 3 phase load with phase failure.
my goodness raymond! there some lovely large fuses! I'd realy like one of them mate lol.
enjoyed ya video raymond thanks for sharing 😉
👍👍👍👍👍THUMBS UP 👍👍👍👍👍
Anthony
⚡High1voltage1rules⚡
I can prob find you some inverter parts if you're after caps, chokes, coils, relays etc
+Boetang123 hello mate, very kind of you yes that would be Awesome, what country are you living in mate??
many thanks 😉👍
Anthony
High1voltage1rules
+anthony treacy (high1voltage1rules) I can post you one if you want, will check out the postal costs to the UK.
+RODALCO2007 hello ray' no thankyou friend. I'm sure I'll come across one some day in my travels in the scapyard. as if you go to post one of them it will cost an arm and a leg mate. there very heavy! and the postage will be expensive for sure lol to the UK.
it was kind of you my friend. 👍😉👍😉👍😉
Anthony
+high1voltage1rules UK Based - sry got Stuck in Wales this week so couldn't answer. Will see what I can find - antyhing you need in particular for projects?
why are the fuses so big I would expect more that 25 Amps
+mqe73M This is 11kV, so there is a lot of energy that needs to be contained once they trip (not sure what kind of voltage drop they have at time of tripping). Also, you want the terminals far apart due to the voltage difference.
+Henner Zeller Correct, thanks for your fast reply.
+mqe73M These types of fuses go up to 112 Amps as far as I have seen them in the field which supply a 1.5 MVA transformer.
The 25 Amp size is usually fitted for a 250 or 300 kVA transformer which yields in 417 Amps / Phase at 230 Volts.
12kv OEFMA 35.5 A ESI 1 pes amount tell me
My contact number 9536829014
why does it have oil?
+biscuitownz maybe to keep them cool?
+biscuitownz Oil cools and is a good insulator. And it keeps the moisture away. You find that in essentially all high voltage/high energy devices such as transformers.
+biscuitownz Insulation, with no oil the 11 kV would flash over across phases and certainly across the switching contacts.
oil is insulation..before operate the switchgear makesure check oil level indicator is enough..it is very dangerous if the oil is not enough when u switching, flash over will happen..thats why only the authorised person can operate the RMU
"it could be a white tail" are you serious man? it was a harmless little huntsman. Whats more is if you have huntsman spiders in your house or wherever, you wont have white tails. The huntsman's wont tolerate them.
Please deinterlace in the video editor. This is horrible :( Ofcourse it is the fault of the youtube that they don't deinterlace the video on processing.
+Retro tévém
The video plays and looks perfectly fine for me ...