How I troubleshooted a tripping MCB

A tripping MCB is nothing uncommon and I have troubleshooted the faulting device many times before, but this time was interesting and challenging; hence the post.

We had this nagging issue of our master MCB tripping every time we turn on the ceiling fan in one of our bedrooms. To complicate the problem further, the fan is a designer fan and has 3 light bulbs and a built-in speed control (via hanging strings). So the faulting electrical component could be one of the bulbs, OR the speed-regulator inside the fan, OR one of the fan's electrical components (capacitor, coil etc.,), OR the speed-regulator on the switch board OR something that I didn't think of then.

The regulator on the switch board was the least of my suspects, as my first suspect was the bulbs (hunch!) or something in the fan. Removed the bulbs and tried, no use. Opened the fan's casing and looked for any obvious burns or something -- no sign of any electrical fault. This doesn't rule out a problem with the fan, but I wanted to cover all easy approaches before getting into disassembling a fan.

Just decided to checkout the switchboard. As I opened the switchboard, it was evident! As you see below, I could see a burnt regulator casing with some internal leakages.

It appeared like, this was the issue. Since our fan has a builtin regulator and I didn't have a spare one handy, I decided to short the regulator off the circuit and use the fan's strings to control the speed. Changed the wirings quickly and tried, and Viola! the fan is running normally without tripping the MCB. Even the fan's built-in regulator worked.

(Pic: had just taken the regulator off the circuit) 

With sense of satisfaction, I switched off the fan and closed the switchboard completely and screwed it tight. All done, so wanted to try for one last time that all is well. I turn on the fan, and the MCB trips! Wow, that's something :)

I had to stop for a while, as I couldn't come up with a theory for this. As you might know, the typical household switches control only one polarity (typically phase/line), the neutral goes to the appliance (fan) directly. The possibility of a short-circuit inside a switch board is pretty less (except if the switch board has a high amperage plug or something, that controls both polarities). And in this case, the MCB trips only when I turn on the fan. So it should be something related to the switch, but the switch has only one polarity! I was pretty sure, I'm missing something, because I couldn't explain the behavior.

The hint I got was the fact that, it all worked until I closed the switchboard. I just realized that our MCB also has Earth Leakage Protection. So it's probably not a short, but earth-leakage. On a closer look at the wiring that goes off the switch, towards the fan, I could find this:

In one of the joints, the insulation had burnt a bit, exposing few strands of the wire. When I closed the board tight, these strands came in contact with the metal casing inside the switch board, which is grounded. This triggers a leakage on the earth line and the MCB trips. I just had to redo the insulation with new tape, and that was it. The fan is running fine since then, without tripping the MCB.

Heavy rain in Bangalore

Heavy rain lashed eastern Bangalore today noon. I was driving on the Marathahalli outer ring road then. Visibility was terribly low. My car's wiper could barely manage even at its full speed swing. I could barely see anything beyond 50 meters. Every car was crawling at 30kmph while the normal speed would be around 70-80kmph (the speed limit is 60kmph btw).

See the photoes. It was shot near Kadubeesanahalli junction, Marathahalli Outer Ring Road, Bangalore (15-Aug-2010, 2.10 pm.).





It was fun!! I've never driven earlier in such a heavy rain. It lasted at least 20 minutes like this.

The high beam non-sense

I am getting to feel that the high-beam non-sense has tremendously increased on the roads in India in the recent times. With more people starting to ride on roads, with more and more powerful bikes and cars coming up, this has really become a PITA.

I wonder if (those) people even know that there are ways to control their beams. Maybe people like that extra indicator glowing on their dashboard, without bothering to worry about what it means. Not just cars, these days bikes' beams are also too bright to withstand. I hate these bike manufacturers for providing such big domes and reflectors -- specially the pulsars, unicorn etc., I can really feel that pain in my retina and like everyone else I would struggle to see through. No need to mention the consequences on the ride.

The other day, I started from office in a bad mood (as usual). Was driving my car on the service road in Outer ring road, Bangalore. There was an opposing car with high beams (nothing uncommon). It was really too bright, and with the scarce lighting on the service road, I could only see those two head lights in the whole world around me. Being frustrated already, I didn't want to ignore this. I thought I would at least let him know how it feels. So I just put my headlights on high-beam and drove towards him :) I was happy that he would have learnt a lesson by now; but interestingly, as our cars cross each other, this guy stops his car and scolds me for my high beam and leaves. Hmmm. feeling totally helpless when you are frustrated? priceless!!

Nothing is going to change, until this is seriously considered a traffic violation.

wassup...

I never thought I would run into such a long pause (2 months) in my blog. The reason is very simple : I had too much to write about, and I really didn't want to write all that. I have been (and am) conscious of the fact that I don't want to dump in too much personal info into this blog -- and that's why this silence :) People who know me personally might know how much my life has changed.. okay, this is why I didn't want to write!! shhhh.

I will definitely come back with a lots of useful info, that I came across during the past 2 months...lots to write. stay tuned, this blog is still alive!

Expect few more weeks of silence from my side!

I wish I were a doctor

I'm an engineer by education and profession; all along I've been happy and so satisfied about it; but not any more.

Engineering explains most of the things that happen around you every day. As I remember

• 'newton's 3rd law' while walking;
• 'doppler's frequency shift' from the horn of a speeding car/bike;
• 'raleigh's scattering' looking at the orange sky;
• 'frequency spectrum' while on a traffic signal pondering about why red is stop and green is go;
• 'acetic acid' when the bearer serves me vinegar for the fried rice;
• 'potential difference' when a crow casually sits on a metallic electric wire;

(and more ...)

....I've always enjoyed my education (as if I were Neo looking at The Matrix :P). No doubt that I still enjoy my education, but there is rather something else that is much more important to understand than all these --- yes, that's our human body.

=== what follows is my own understanding of a disease; do not rely on the information here if you are looking for some critical information on this disease. ===

I was totally devastated when I got to know about this disease (not sure if I can call it a disease) called 'Guillain-Barré Syndrome'; commonly referred as GB syndrome. It is mentioned that this disease is very uncommon and the chances of this disease is just 1 or 2 in 1,00,000. What took me to surprise was the complication of the disease; I never had imagined such a problem was possible. In simple terms, GB-syn is a situation wherein our body's immune system starts destroying our own nerve cells! OMG!!! Apparently there seems to be a generic term for this kind of complication -- autoimmunity. As time proceeds, the disease gets worse, wherein there are too many antibodies generated to act against our own self. A friend of mine is affected by this disease and hence I know about this; the disease progresses at very fast pace -- to given an example, my friend suspected some abnormality on 1st day and went to the doctor; on 2nd day he felt so weak but managed to go the doctor with his friend; on 3rd day he was paralyzed literally and could not move :( The disease is so complicated and the attack is so acute that lack of an immediate medical intervention might even result to death.

In spite of understanding so many things around us, there are things within us which we don't understand and those can put us to stop. To me, if I don't have any idea of how my body works, I don't have to be proud of knowing how a computer works!! after all nothing is more crucial than our lives. Now that it is too late for me to realize or react, I can only wish I were a doctor, to have understood at least a portion of my body!!

One thing is clear that happiness/sadness is subjective and relative. Someone who has GB-syndrome would really not worry about this economic slowdown or losing job or about a huge homeloan on a declining real-estate; there are always worse things in this world; so be happy for what you have and enjoy your days!!

New forms of telemarketing

Thanks to the NDNC (National Do Not Call registry) in India that the telemarketing's nuisance has become really tolerable. There have been days where I would come out of a meeting just to attend a call from an automatic advertisement system. These days I hardly get any message/calls. Great move! This isn't the news, but...

I am starting to realize 2 new trends in telemarketing to get away with the NDNC regulation.

1. When I call the service provider (bank, phone etc.,) for some query, they make sure they advertise at least one product to me. They make use of the customers like me who wouldn't just disconnect the call once the query is answered, but would finish the call completely (including a 'same to you' for a 'have a nice day' from the executive). One good thing about this approach is that, they have become much more pleasing than before -- that's the way to make you listen to their advertisement at the end. That's technically not violating NDNC!!

2. First one is rather acceptable; as this happens only when "I" call them up. The second type is totally ridiculous. These people create a website (or a page in their existing website) to ask them to call us for more info. These days I see a number of websites which have the option of 'Register for a callback for more info' kinds. As earlier, the companies get hold of a database of phone numbers and names. I "guess" that they also have a separate team which would just generate fake requests at the website with those info from their database. Now they are free to call us, claiming that we asked for the call. To make it so formal and legal, they also send an automated SMS which says something like 'Recently you had asked for more info on xxx. Thanks for your interst in xxx. Within 24 hours, our service representative will call you back'. Clever??!! I really got pissed off when I got such a message last week and without surprise they also called me the next day. I finally confirmed from him that the case was registered with a wrong email id but with correct name and mobile number. When I claimed that I never raised any request, he didn't seem surprised; but was rather more interested in still explaining me the product -- this says it all, that it is a practice, not an accident. He claims it coolly that any of my relatives could have registered for me -- I could only LOL!!!

Statistics on browsers usage

While I was analyzing some statistics on my blog, I came across this interesting info. Based on so many visitors who visited my blog from more than 100 different cities around the globe in the past two months (since it's inception), this is a summary of the browsers used by the visitors.

Browser               % of users
--------------------------------
firefox               62.09
IE                    28.83
chrome                6.28
safari                1.86

I think it is possible that these numbers are slightly skewed because the nature of the users visiting my blog are mostly similar (someone related to a computer profession most likely). However, from the huge gap that is existing between the numbers, I would not expect this order to change even if the numbers do.

At least to me, the numbers aren't surprising. That's what they deserve.

Abouticon

The great indian petrol bunk fraud

This fraud is nothing new to most people who fill petrol to their bikes/cars in India. Neither to me -- but a recent recurrence was too enraging that I want to atleast shout out here in my blog.

For those very few who are not aware of this fraud (most likely because of not personally going to fill petrol), here is the how it works:

1. Assume a person in front of you fills petrol for Rs 100.

2. You go next and ask him to fill in the petrol for Rs. 200 (here is the catch, they would be able to do this easily and successfully when your fill amount is higher than the previous one).

3. He shows you zero and exactly then, a guy standing on the opposite side of the meter across your vehicle will call you 'sir how much sir' or 'sir is it by card or cash sir' or 'sir sir sir...' until you get distracted and turns towards him.

4. If you aren't aware of this trick, you would naturally react to your impulses and turn towards him (away from the meter) -- at this point, the person who is (actually pretending to be) filling just presses a button on the machine which shows the previous reading (which is Rs.100).

5. When you turn back, he pretends as if he has already filled for Rs.100. You would obviously say it is for Rs.200.

6. With the happiness of looting Rs.100 in a matter of few seconds, he would again configure the meter and fill in for Rs.100 more.

That's the end of the trick and you have just lost Rs.100. We would feel like an idiot and he is ready for the next attack. Someone is waiting in queue to get looted.

Having explained the fraud, let me come to the recent incident. I'm very much used to this fraud that I've never been cheated like this (except once -- when I learnt it the hard way). Last week, I was in a petrol pump (Beware: it is the BP petrol pump in udipi garden signal, BTM 1st stage, Bangalore) in queue. I could clearly see this fraud happening just in front of me and unfortunately that guy infact got cheated. I was atleast 5 bikes away that I could not do anything about it (maybe I should have). In some ways it was very enlightening to see those people's expressions at the time of fraud. The guy after looting Rs. 100 immediately became so polite to the bike rider; after all he is the one paid Rs.100 for nothing in no time. I felt like kicking him in his face. There is one guy who keeps a look out for the amount that people are going to fill so he can time their attacks. And if you somehow manage to crack their effort, they look at you like enemies. grrrr..

Ok, then came my turn in the queue. The guy in front of me filled in for Rs.100. I wanted them to try this against me and so asked him to fill in for Rs. 200. Ok, all set. This guy shows me the meter reading zero and puts in the nozzle into my bike's petrol tank. I could see the other guy coming around me to distract. I was just looking at the meter, it wasn't moving at all. The other guy calls me, I showed no response while still looking at the meter. After a delay of around 10 seconds, there was still no petrol and no meter movement (as he was waiting for me to turn around, to press that magic button to get him Rs.100 in no time). At this point, I really got pissed off and I shouted at him that I know what he was trying to do. He pretended as if he is innocent. Then I told him that I even noticed that they cheated a guy infront of me and I'm going to complain about this. This is when I got the shock of my life. He simply laughs at me and tells me 'Talk in Kannada, no english, no hindi'. I'm sure he understood whatever I said, but found an easy and daring escape. The kind of dare he had in his tone was so shocking; both were just laughing at me --- I should admit I felt like an idiot. After staying in bangalore for 4 years, I regreted that I never bothered to learn kannada (atleast bad words so I could have bashed them). The kind of confidence he had in this act, shows that he is not doing that alone or just with two. Almost every other filler in the bunk does this, and every bunk does this. If someone complains to their manager, they will play an immediate drama and bash that employee or even fire him infront of us -- but nothing really happens. I believe someone sitting in a AC room also has a stake in this.

It is really disgusting that we really have to fight for basic loyalty and that we are unable to do anything against such a common fraud. It has become so common and widespread that if you are ever cheated, instead of blaming them you would be blamed for your negligence.

I'm sure just like me you might have heard and experienced a number of such incidents.

EKSI -- an acronym of recent times

Recently I came across this acronymn EKSI being used widely in forums (Later I realized it was only used by those who know tamil). I had no clue as to what it means and googling does not reveal anything obvious.

Finally I had to ask one of those guys who used this and it turns out to be the abbreviation for the most famous tamil dialogue 'Enna Koduma Saravanan Idhu' --- EKSI :)

For those who don't understand tamil, this is a dialogue said by actor Prabhu to actor Rajini Kanth in the film Chandramuki (tamil). This dialogue became so famous and is used in various contexts generally to insult a work in a humorous tone :)

Watch the original clip and actor Prabhu's reaction: LOL!

just back...

Just returned from a week long vacation for Christmas -- and that's the reason for a short silence in my blog.

Tired of driving my car for 1300 kms in just 6 days (out of which 1000 kms in 2 days).

Back with a lot of stuff to share, stay tuned...

Minesweeper - a game of luck?

A minesweeper-game a day keeps your logic alive -- well maybe only as long as you're a beginner; as at some point our brain being too smart, does not want to apply the same logic again and again, and starts looking for patterns to quickly clear the empty lands -- yes, memoization as in dynamic programming ;)

When I get a quick break, I like playing a minesweeper game. When my luck is bad on that run, minesweeper turns into a game of luck. It generates a pattern wherein there aren't enough cues. Usually people claim that minesweeper has hidden cues "all" the time; it is just that the user does not notice them. Seems not.

Here is the snapshot of such an ambiguous position I got recently:



There was only one mine left; two tiles to be cleared. Now, atleast I dont understand where shall the mine be. Both seem equally probable. Does anyone have a different opinion?

I managed to get unlucky that day and lost the game even after correctly marking 99 mines :(



Better luck next time with minesweeper!

The Forum -- On Dec 6th

'The Forum' is a famous shopping mall in bangalore. It's like Chennai's spencer plaza. Every molecule in bangalore would know about it.

When I woke up today, I did not remember that today is the notorious Dec 6th; failed to remember even the recent t e r r o r attack warning for Dec 6th on airports. It was just a yet-another-saturday for me, but only until I reached the Forum. The bike parking didn't surprise me, except for the additional security checks on the bikes too. I could get a slot close to the entrance of the parking space, so I did not bother to look around; As I entered the Forum, I could sense the difference immediately; at a first glance it was "deserted" -- Forum and deserted are almost literally an oxymoron.

The immediate thought in my mind was "Did I miss any news?". Never mind, took out my mobile and immediately glanced through the news on the internet to check if I missed something unusual. Thankfully nothing worse. That is when it struck me that today was Dec 6th and the attack warning. I could understand the panic.

After a small while, I could see more faces and felt a bit better than how it sounded earlier. However, I've never seen Forum like today in these three and half years I've spent in Bangalore. I could almost see the complete stretch of the forum mall from one end (people who have been to Forum would know if this was ever possible). At 2.30pm atleast 10-15% of tables in transit were empty. Infact, transit was the only crowded place I could see today. Very few people in the corridors; Overall it was atleast 40% less populated. I was convinced that I should leave.

On the way back, a fire-engine was blazing through the bangalore traffic with terrific siren. For a change, today everyone gave way for it. I could see that everyone stopped for a while, and looked bewildered at the fire engine -- just like me wondering where would have been the fire now and why??!!! hmmm... people moved on with a sigh!

Finally I returned home safely (not from war, but from weekend shopping). Where am I living ?!!

better late than never...

For many years now, I've had the intention to blog, but never found time. After suggestions from quite a bit of my friends, I've finally decided to blog.

hehe, then thats not me; but this is actually how many people whom I know have started blogging. ;)

I knew about blogging few years back, and in fact I created this URL in 2004. To be frank, I never thought I would ever blog in my life. I'm pretty lazy in writing (I remember not answering few questions in my MS exams, because I felt bored of writing and I had already answered for 90%). I know of some people who have recently started blogging, and some people who have recently stopped blogging because they no longer find time. Let me see how long this works for the lazy me.

I believe after many years, it would be wonderful for me/others to glance through my blog to know how I've been and how I've grown. And believe this is a nice way to share knowledge and more importantly archive them.