[Prowler]

Originally Posted by Thad E Ginathom

I have had plenty of short-sharp-buzz 240 volt shocks, touching the wrong thing. I am lucky: nonthing bad happened. But the worst thing was...




Be safe working near as well as with, electricity.

(my first analogue multimeter, I blew up, poking around inside a TV, with no clue what I was doing <blush>)

They say in scientific circles - " It is the mills that kills and it is volts that jolts ". Actually it is the current that kills people and animals. It is not the volts per se that is responsible for electrocution.
The HT coming from the LOT (line output transformer) of conventional CRT has plenty of Volts but can source little current. Besides it comes at 15625 Hz which due to the skin effect will pulse over the skin leaving the recipient's internal organs relatively harmless. The normal domestic supply at 50 Hz has no skin effect and as a result can cause internal damage.

In a domestic scenario, a microwave oven has a circuit driving the magnetron that can supply about a couple of Amperes - enough to cause serious damage usually fatal.

[Thad E Ginathom]

Originally Posted by R2D2

How did you get 400V as domestic supply. Assuming this was the home meter enclosure? 440V is mostly for industries and supply to housing colonies with 3 Ph step down transformers like the one I live in.

Three-phase supply to house.

I've seen cats, squirrels and birds get instantly electrocuted with a loud bang and a puff of smoke. The dead animal looks burnt to a crisp.

The SEB linesmen switch off power before entering the enclosure. We are all bags of saline solution after all.

Sorry if I told this story already on this thread, but we recently had a burnt-out connection with one phase where it entered the main EB fuse. We have an EB-engineer friend. I expected they would kill the power first, but he cut, stripped and refixed the incoming cable while it was live. He did so with great care and obvious confidence in his insulated tools, but it scared me to watch!

That's why those HT cabinets and transformers are fenced off to discourage people and animals from getting too close.

The streets are full of three-phase junction boxes (I don't know why: they call them pillar boxes, which is the old British name name for a post box) with doors open or completely missing. Every one is a death trap.

[goswami.j]

Looking for a car trim removal tool kit. Few good ones available on amazon.com but priced too high including the international shipping charges. Anyone bought recently ? Feedback & pointers will be useful.
I plan to use the kit to do a DIY installation of dashcam installations on my 3 cars to begin with & then one day dampen all the doors of the rattle vehicle called Maruti Swift VDI.

[R2D2]

Originally Posted by Prowler

They say in scientific circles - " It is the mills that kills and it is volts that jolts ".

As someone said "V will not kill, but I will"

But yes, the amperage is the problem not so much the voltage. If it was just high voltage I wouldn't be here to type this.

Originally Posted by Thad E Ginathom

Three-phase supply to house.

Was there a phase short? IIRC I think that's when voltage goes high. Did you get the wiring checked?

He did so with great care and obvious confidence in his insulated tools, but it scared me to watch!

He obviously knows what he's doing but then people make mistakes and in this case there may be no second chance. Wish he'd be a little more circumspect in his actions.

The streets are full of three-phase junction boxes (I don't know why: they call them pillar boxes, which is the old British name name for a post box) with doors open or completely missing. Every one is a death trap.

Some years ago, a lady living on the outskirts of Pune in a house built under a electricity pylon (construction not permitted but you know how it is), was doing her laundry on the terrace. She was setting the clothes out to dry on the clothes line and flapped/waved a wet bedsheet under a 100-200 KV transmission line.

There was a giant spark that jumped from one of the cables on the pylon to the bedsheet and it was enough to kill her instantly. A needless death but our people never learn to take safety seriously or respect electricity.

[amitk26]

Originally Posted by R2D2

Some years ago, a lady living on the outskirts of Pune in a house built under a electricity pylon (construction not permitted but you know how it is), was doing her laundry on the terrace. She was setting the clothes out to dry on the clothes line and flapped/waved a wet bedsheet under a 100-200 KV transmission line.

There was a giant spark that jumped from one of the cables on the pylon to the bedsheet and it was enough to kill her instantly. A needless death but our people never learn to take safety seriously or respect electricity.

You can not compare a household / commercial 240 V 3 Phase supply with HT transmission line. There is no major difference from what you get in normal single phase connection , Just you are getting 2 more line 120 degrees apart in phase. Most linemen of state electricity boards work on live wire with help of thick insulated glove , pair of pliers and dry sandles in feet. Principle is simple that you should not touch an neutral or earth while working with live and should be dexterous with pliers. A 3 phase supply is no-more or less dangerous then a single phase 220V connection.

In M.P. all household connections beyond certain consumption were changed to 3 phase few years ago so we have a 3 Phase connection in our home there.

BTW: Transmission lines are generally 32 KV or 64KV in Cities /towns and you can hear them from audible hum of 50Hz and a distance of 5 M is required for any construction from 32KV line. However unauthrized constructions give rise to such accidents.

132 KV or 220KV transmission lines have towers almost double the height of 64KV and they travel intercity and are stepped down to 32KV at substations in outskirt.

[R2D2]

Originally Posted by amitk26

Most linemen of state electricity boards work on live wire with help of thick insulated glove , pair of pliers and dry sandles in feet. Principle is simple that you should not touch an neutral or earth while working with live and should be dexterous with pliers. A 3 phase supply is no-more or less dangerous then a single phase 220V connection.

Yes, I am aware of what you say about 3 phase supply. The example was only to drive home the point on how people in this country take warnings to stay away from power lines etc casually or most commonly ignored.

I've seen SEB linesmen work on the cables with a thick yellow rubber glove and basic footwear. That may suffice but thing is accidents do happen when working with live conductors and that's what really bothers me. It's an accident waiting to happen.

However unauthrized constructions give rise to such accidents.

These are grid transmission towers which were outside Pune city limits and unauthorised constructions i.e. 1-2 storey 'pukka' slum residences made of bricks came up under these pylons on a hillside (hence the reduced vertical distance) despite warnings from the SEB to not construct there.

Political interefence meant the SEB couldn't take any action and this lady died. I am not sure what happened thereafter but I can guess nothing did and people continue to live there in blatant disregard for their own safety.

For e.g. Homes Close to HT towers

I quote:

There should be a minimum horizontal distance of 14 m from the centre of tower for any construction which is located close to the 100 KV HT cables. There should be a minimum horizontal distance of 17.5 m from the centre of tower for any construction which is located close to the 220 KV HT cables."

132 KV or 220KV transmission lines have towers almost double the height of 64KV and they travel intercity and are stepped down to 32KV at substations in outskirt.

These are the high power transmission State level grid lines. They are between 100-200 KV AFAIK.

And yes, you can hear the hum if you get close. It's not just the risk of accidental electrocution that poses a risk but EMF/EMR exposure is considered unhealthy over the long term.

[Thad E Ginathom]

re the meter that punched me in the head, our EB friend took a look, scratched at it with his ordinary mains-tester scredriver, which glowed bright, and told us that we would have to officially report it and get a new meter fixed. He also told me off for being unsafe . All the old metal meters were being replaced at the time, and ours was, before we got around to doing anything about it.

Looking back, and remembering his insulated tools, I think his cable stripping knife was a home-cobbled affair! They don't even give these guys a decent toolkit!

Dealing with one phase is no different to dealing with 240 volts, which it is, As I understand it, the danger is not so much in touching the phase and earth (yes, I know 24v can kill) but in touching one phase and one of the other phases.

Back to tool buying...

Originally Posted by R2D2

What you need is a feature called 'in-rush current' measurements available on mid and higher end clamp meters. These CMs are generally used by electricians and refrigeration technicians maintaining inductive loads like motors and compressors. Here's one such model: Mastech Clamp Meter

Originally Posted by aim120

I have that mastech model ms2108, it's good for measuring DC amps but it takes a while to Zero the reading for measuring AC current and but yes it does have the inrush current capabilty.
Uni-T mid to high end versions of their multimeters are becoming real value for money(compared to fluke), very very close to some reference level $700+ bench multimeters.

I bought the mastech in SP road for 3k in 2012 but then again dollar was Rs 5x.xx, now its more then 60.xx plus earlier it was 5% vat, now its mostly 12 or 18% gst.

I ordered it from China, 3k Rs. Now I seem to remember hearing something about customs causing problems with electonic/electrical stuff, so... a Rs.3k gamble maybe.

[R2D2]

Originally Posted by Thad E Ginathom

I ordered it from China, 3k Rs. Now I seem to remember hearing something about customs causing problems with electonic/electrical stuff, so... a Rs.3k gamble maybe.

There's no problem per se. They'll only ask you to pay the Customs Duty after summoning you to the GPO/HPO with proof of price. But all this depends on the Customs officer(s) who examines the package. Sometimes they just let it go through without charge.

I prefer buying locally even if at a slightly higher price because I get a return window and warranty support.

[diyguy]

My friend had to pay the duty amount to the postman. Not sure if he was scammed or if it was official. I've seen other reviews on aliexpress who have got receipts of valuation and duty to be paid to the postman.

[Thad E Ginathom]

I check the price differences and delivery times before going ahead with my newly acquired China-buying habit.

First thing is that I should not want it now!

[manishalive]

I want to buy locally but some stuff is just not available and most of the shops do not encourage DIY guys. They just want to deal with standard stuff. Case in point being bullet connectors for my old car. I wanted glue backed cloth tape again not available. And then for some stuff buying online from China or HK is cheaper than driving all the way in the mad mad traffic.

I need a suggestion guys, I am in need of a vacuum pump. - 1 bar pressure to help in vacuum degassing of silicon / epoxy for mould making. I see the professional ones are all very costly 4-5k INR. So was looking for alternative.

Can a fridge compressor work. Also how about the small hobby vacuum pumps the size of your palm.

Also where in Bangalore can I get my Dremel repaired. Looks like the speed control has conked off.

[drsingh]

Originally Posted by manishalive

I want to buy locally but some stuff is just not available and most of the shops do not encourage DIY guys. They just want to deal with standard stuff. Case in point being bullet connectors for my old car. I wanted glue backed cloth tape again not available. And then for some stuff buying online from China or HK is cheaper than driving all the way in the mad mad traffic.

I need a suggestion guys, I am in need of a vacuum pump. - 1 bar pressure to help in vacuum degassing of silicon / epoxy for mould making. I see the professional ones are all very costly 4-5k INR. So was looking for alternative.

Can a fridge compressor work. Also how about the small hobby vacuum pumps the size of your palm.

Also where in Bangalore can I get my Dremel repaired. Looks like the speed control has conked off.

Fridge compressor will work very well. My Auto AC mechanic uses one for hours professional use. Look up videos on you tube and get it made locally.

For the Dremel repair, search on Indiamart /just dial for distributors/service centres in your city. Call them up and ask for repair services.

[Thad E Ginathom]

Originally Posted by manishalive

Also where in Bangalore can I get my Dremel repaired. Looks like the speed control has conked off.

Have you checked google about this? Or searched Youtube. It was too long ago to be specific, but I remember seeing something on Youtube about fixing the switch/speed control.

[Chetan_Rao]

Looking for a generic portable toolkit with a multi-purpose motor drill. Bosch GSB 10 looks decent.

Use case: DIY utility jobs around the house.

Suggestions/advice?

[Thad E Ginathom]

You are always going to acquire more tools, which you cannot then put into a fitted box.

The Stanley bag of tools looks like a good starter kit. Add power drill and bits to your choice.