I have no idea what you are talking about.. do you?

If the live is shorted with resistance it will have current drain, that mean energy used, if the heat build up it will have bbqing.

you're saying a slow thermal buildup short circuit as in the case of indirect conductivity (surface dust, liquid and conductive flesh)..


but Aeran typed "already off all MCB. When inserting the new fuse, sparks come out and the fuse blow" that describes an instantaneous short circuit..

Anyway the easiest way to check is to disconnect both ends of Live Neutral and check for continuity between the two..
If there's continuity then its a direct short..

Yes, and his problem maybe in between the meter and mcb main fuse/switch. That possible explain even after switch off all mcb it still have spark. Possible some shorting between there, or someone stealing electric, or maybe did some creative wiring to bypass meter.

yes.. So best thing is to get an electrician if not sure as we're talking mains electricity here and it can kill you..

Guys, finally can get electrician to come and see this morning. Will update later.

No; I'm not using any 'creative' wiring to bypass meter. Though previously I do notice the meter tend to spin a bit fast.

Hope you find the problem.

Update: Confirm wire between meter and MCB was shorted.

That is good to know you found the problem. Lucky it didn't catch fire. I hope the TNB bill won't go crazy, since is a temporary short / resistance shorted could eat up lots of energy.

Didn't you feel light or some of your equipment behaving? Assuming is resistance shorted, voltage into your house very likely will be way below 230v

Same problem at one of my properties. No trip at all but outside fuse near meter blown 4 times over a period of 2 months. Found out later that one external cable extended to a birdhouse was bitten by squirrel/mouse thus causing live and neutral shorted from time to time.

you are one cuckoo fella.. people say incoming live/neutral already confirm short blow fuse still say resistance short, talk voltage ?? Pls stop talking cock !!!

Already blow fuse means no more supply !! You talk what !!

If his house had fuse blow only sometime and not always is either a resistance short or expose short when movement happen. and If all MCB are trip are up Meter will not run, this only happen because of leakage due to lousy insulation or faulty meter, if leakage are major it will cause voltage drop. During my college time, i been working in factory and old house wiring and seen many of such cases.

Pls stop.. You can use your bullshit on some factory but not with me.. Please go home study your basic electrical 101 then come back and talk..

By right, the MCB should trip 1st.

Time to change the MCB.

It may not trip the main switch if happen between the meter and main switch . Most common happen with old houses with 3 phase meter at gate pillar when underground cable is damage.

Not TS case. But aeiou228 case.

MCB won't trip if the short circuit happen before the MCB incoming.

While aeiou228 case is after the MCB. Since the MCB have lower Amp rating than the fuse, it should trip 1st before the fuse.

Ok, if is extended from inside the MCB yes, if its extended from the meter will blow the main fuse..

This post has been edited by weikee: Jun 16 2016, 09:17 AM

The shorted cable has a dedicated MCB extended from the DB in house A and all the way to a birdhouse B. The cable shorted in between A and B.
Only realized cable shorted upon seeing a spark at the cable.
I did ask my electrician why there is no tripping but was told when live and neutral shorted, the MCB wouldn't trip but the main fuse blown instead. Can any sifu care to explain ?

Every DB will have one main fuse or some call it main breaker. There are many possible how your house cable is extend,
01) Extension/tapping before the main fuse
02) Extension/tapping after the main fuse.
03) Extension/tapping after the main fuse and one MCB.

<If all Circuit Breaker function as normal> and your Cable A & B are shorted
extension 01 method, only the incoming fuse beside meter will burned
extension 02 method, the main fuse will trip making entire house will have no electric
extension 03 method, usually is the prefer if current are not high. The individual MCB will trip first. This is also good if you want to totally shutdown the supply from outside.


You can test it out by trip the Main fuse in the DB Box. and if the birdhouse still have power mean is using method 01.

Thank you sir,
These are the info that I can gether.
1) when cable A to B shorted, the was a big spark, main fuse blown off and house A and birdhouse B no electricity.
2) before knowing the actual cause of the problem. wireman came replaced the main fuse in the morning but evening fuse blown again.
3) wireman disconnected the birdhouse cable from MCB in the DB, no more blown fuse but birdhouse B no electricity.
4) upon checking no wiring problem inside birdhouse B, I asked wireman to reconnect the birdhouse cable to MCB.
5) it lasted for a few days before the main fuse blown again. Replaced the fuse again without disconnecting the MCB for the birdhouse for further investigation.
6) break through came when a spark happened before my every eyes. A and B is about 40-50m apart and the extension outdoor cable is supported by cable pole and trees. The spark happened at a tree.
7) wireman fixed the exposed cable and no more blown fuse ever since.

So which extension method in this case?