Electric shock

[JohnnyJazz]

I recently converted a storage room in our home's garage into a workshop. First thing I did was to install an aircond. Then I plugged in my computer. Then I got a problem, when I touch the computer, I got a small electric shock. The electrician came and said it was a grounding problem, he installed an earth line, problem solved.

An other electrician came recently because we're going to have some renovation in the house and said, beside the kitchen, there is no ground anywhere in the house. So the question is, why do I had a problem in the garage and nowhere else in the house ? The same computer was plugged before in the living room without problem ...

[Crossy]

The tickle is caused by a very small leakage through the computer's mains inlet filter (a normal effect and nothing to worry about), grounding the box sends this leakage to ground.

Your garage floor is likely more conductive (concrete floor) and nearer the ground (damp) than the previous location (wood floor, carpet and/or upstairs perhaps).

That you didn't get the tingle before was more by luck than anything else.

[JohnnyJazz]

Thanks for the explanation Crossy.

As we are going to go through some renovation, does it make sense to ask the electrician to add a ground to every socket in the house ? or to specifics ones ? or is it useles ? The electrician told us there is no ground anywhere in the house beside the kitchen and so far we are ok. Beside this computer problem of course and now that you told me that it was luck that we had no problem before it gets me worry.

[lopburi3]

Make sure you have some type of low amperage leakage shutoff system (such as Safe-t-cut) or other RCCD. These protect even without ground and can save your life. But you should have ground installed if doing renovation as it will not cost that much more and will allow even better protection (hopefully current will never get to you with a ground system in place).

[Crossy]

L3 got there first.

Since you are already renovating I would bring the whole electrical installation up to current standards, as a minimum:-

1. All grounded outlets
2. Grounded water heaters
3. Front end RCBO (Safe-T-Cut)
4. Correctly sized cables and breakers

[JohnnyJazz]

Tks for advises LB3.

Crossy, I will keep in mind the 3 points you mentionned for our next meeting with the electrician. According to people who came to give quotation for the renovation, the house was built to good standard and is in a reasonably good shape (20 years old house). Keeping that in mind, beside the 3 points you mention, would you have some kind of check list for our next meeting with the electrician ? Like things that need a check / rework after 20 years and things that wasn't in fashion 20 years ago and are now a must do ?

[bankruatsteve]

Make sure you have some type of low amperage leakage shutoff system (such as Safe-t-cut) or other RCCD. These protect even without ground and can save your life. But you should have ground installed if doing renovation as it will not cost that much more and will allow even better protection (hopefully current will never get to you with a ground system in place).

Just to clarify: RCD will protect from serious injury due to ground fault but the tickle and even stronger zap you can get from ungrounded class-1 device are well below the (normal) RCD 30ma tripping threshold. Only proper ground will prevent for that.

[bankruatsteve]

Most of the older Thai homes I have seen are ridiculously sparse when it comes to power outlets. That leads to the extension wheels that get daisy-chained and present numerous hazard potential. I cringe every time I see them dangling in and around the kitchen worktops. Since you are renovating, I would give thought to putting outlet everywhere one might be needed such that extensions are never required. I like to put at least every 2m of wall space and even more in the kitchen - giving two circuits for kitchen appliances.

[EmptyHead]

My wife has just built a shop and the electrician came round today. I asked if he will put an earth rod in the ground and use an RCD mainswitch. He said he could do it, but looked a bit funny. And you know how things are here. They say yes but mean no.

Then my GF says, "I think it's ok..just a small shop, very safe". So it doesn't help that she thinks like this. (She seems to think farang are too over cautious)

Basically, i want to know if the guy does the job right, especially with the earth rod. So what should i be looking for to make sure its done right?

I don't mind if he doesn't use an RCD. I can put one in myself if he doesn't. But the grounding the most important thing.

He will be coming off the overhead line, by the way. The shop is too far away from the house to come off the house consumer unit.

Thanks for any advice!

Oh and one more thing. What size of cable should be coming in? and what size for earthing? It's a tiny shop (probably 2 lights and 2 sockets, lol)

Edited November 26, 2014 by EmptyHead

[Forkinhades]

^ could you please start a new thread with that question.

[JohnnyJazz]

To add one more information, I have a NAS (Network Attached Storage) which is very sensible, I had to add an UPS because the RAID 5 was constantly rebuilding itself due to errors caused (I guess) by frequent micro cuts. Is there something I can ask the electrician to do to avoid having to install an UPS for every sensible computer device in the house ?

Edited November 26, 2014 by JohnnyJazz

[Forkinhades]

UPS is essential IMHO.

Take a look at the pinned threads and AVR.

[JohnnyJazz]

UPS is essential IMHO.

Take a look at the pinned threads and AVR.

That's what I'm doing, very interesting indeed. But unfortunately I'm not a professional and there are too many details for my little mind to process in such a short time, renovation is scheduled to start in less than two weeks !!! That's why I'm asking what are the most important points I should focus on to make sure it is done properly.

[lopburi3]

There are a lot of bad power changeovers causing a few seconds outage (seems to happen most often on weekends and holidays - either because less business usage or second team working). But for TV and other secondary computer controlled items it is probably not worth installing UPS. For main computer equipment the UPS is useful - even with the normal short life of battery in heat of Thailand. For new computers you might prefer laptop to avoid power issues if an occasional reboot is an issue for secondary equipment.

It is probably not worthwhile installing dedicated UPS power system for house - and would be a nightmare to get proper maintenance. Hard to support the rice cooker or microwave requirements.

[Forkinhades]

I was only talking about UPS for the NAS box, and pc equipment. Where hard drives need to spin down to save your data.

NAS with 2 hard drives and a RAID set up is essential if you want to protect your data.

[impulse]

While Crossy's observations in #2 are probably correct, I'd suggest buying a voltmeter and actually measuring the potential between the computer case and ground.

The OP may have one of those rare cases, and better safe than sorry.

You can get a cheap VOM for $10. I'd suggest spending more for a brand name, because they come in so handy once you have one...

Edited November 26, 2014 by impulse

[charliebadenhop]

My situation-

I moved here six months ago, and immediately got small but bothersome shocks from my laptop.

Had an electrician come in because it was "obvious" to me that I must not have a "ground".

He installed a ground right in front of me, and still I get some shocks, but seemingly a tiny bit less severe than before.

And my computer is plugged into a UPS that switches off and on for a second or two, numerous times a day.

Any advice/ideas?

[MiKT]

You’ll get a blood big shock if you touch mine

[sometimewoodworker]

My situation-

I moved here six months ago, and immediately got small but bothersome shocks from my laptop.

Had an electrician come in because it was "obvious" to me that I must not have a "ground".

He installed a ground right in front of me, and still I get some shocks, but seemingly a tiny bit less severe than before.

And my computer is plugged into a UPS that switches off and on for a second or two, numerous times a day.

Any advice/ideas?

You may have had a ground rod installed but it could be in a dry location. The ground rod needs to be in damp earth to be effective.

[MiKT]

Get a standard consumer box with RCD / RCBO (try Home Pro) and see all previous posts about installing an adequate earthing rod - tech section.

Try not to get one like Crossy's that got attacked by misterious underground "pee" that ate 1.875M of his earth rod in less time than it takes to walk to a 7/11. A cautious man, not to be twice bitten, he is currently installing one so long that the middle-earthers have sent emissaries to complain about the noise.

Also, many computers are not adequately earthed inside the case. If it continues to give you shocks please get it checked.

Also, also, note to others, if you are very hiso you may have shag pile carpet and be getting a build up of "static" every time you walk across the floor which discharges to your computer when you touch it. Happens to loso with some cheap vinyl floor coverings also. Additional Health Warning - in addition to static, you can get carpet burns shaggin hiso's.

[Forkinhades]

Have a look at the stickies guys. All the info there.

[Liquorice]

Crossy, on 26 Nov 2014 - 10:08, said:

L3 got there first.

Since you are already renovating I would bring the whole electrical installation up to current standards, as a minimum:-

1. All grounded outlets
2. Grounded water heaters
3. Front end RCBO (Safe-T-Cut)
4. Correctly sized cables and breakers

I'd only add that you ensure every appliance is earthed and wired back too the Consumer Unit.

The Thais have a bad habit of taking the feeds for showers and air cons from the incoming meter tails, and not from the circuit breakers.

[Bignose]

This has to be the last time I shall post on this subject (not that anyone will give a sh1t:)) as it is now beyond explanation why this still happens and it will always be this way...

I appreciate we are in a third world country when it comes to electrical installations, but why oh why do certain people on TV persist on giving advice to uneducated amateurs?

When back in your "Mother Country" where ever that is, I am sure it is a regulated requirement that a licensed person carry out this work, you know and understand why this is the case so why do you persist in disseminating this information when you know the risks involved?

I have read the replies several times..."It's quite expensive to get someone and it's really quite easy" or "There's just no one available where I live who can do it" or my personal favorite "I've done a lot of research with the drawings posted really quite good"

The bottom line is get your wallets out of your back pocket and pay someone to do it properly, you'll quite happily spend money on grog, your favorite cheese, another movie channel for the television, maybe even a massage from a nubile local, but you don't want to spend it on something you can do your self (or so you think) Get with it and spend the money on something worth paying for...

With every person who carries out his own installation work, we are one more day closer to someone being killed! While I don't like the idea of anyone losing their life I genuinely hope it is the cowboy electrician and not his partner or child...

No matter who it is will you sleep comfy knowing that you helped him along with your expert advice???

Rather you than me Gents, rather you than me...

[asdecas]

Your computer is telling you, in the only way she knows how, that she cares deeply for you.

Do not, under any circumstances, reject her advances; rather, caress her keyboard often, particularly the 'G' key.

You will soon find that everything returns to 'normal' - that is, to indifference.

Edited November 26, 2014 by asdecas

[masuk]

Crossy, on 26 Nov 2014 - 10:08, said:

L3 got there first.

Since you are already renovating I would bring the whole electrical installation up to current standards, as a minimum:-

1. All grounded outlets
2. Grounded water heaters
3. Front end RCBO (Safe-T-Cut)
4. Correctly sized cables and breakers

I'd only add that you ensure every appliance is earthed and wired back too the Consumer Unit.

The Thais have a bad habit of taking the feeds for showers and air cons from the incoming meter tails, and not from the circuit breakers.

and remember earthing to water pipes can be a waste of time, as most are now PVC, not metal.

I ran some reinforcing rod under my air con where the ground was always damp, and ran an earth to my computing gear.

The shocks stopped that we'd been getting.

[JohnnyJazz]

This has to be the last time I shall post on this subject (not that anyone will give a sh1t:)) as it is now beyond explanation why this still happens and it will always be this way...

I appreciate we are in a third world country when it comes to electrical installations, but why oh why do certain people on TV persist on giving advice to uneducated amateurs?

When back in your "Mother Country" where ever that is, I am sure it is a regulated requirement that a licensed person carry out this work, you know and understand why this is the case so why do you persist in disseminating this information when you know the risks involved?

I have read the replies several times..."It's quite expensive to get someone and it's really quite easy" or "There's just no one available where I live who can do it" or my personal favorite "I've done a lot of research with the drawings posted really quite good"

The bottom line is get your wallets out of your back pocket and pay someone to do it properly, you'll quite happily spend money on grog, your favorite cheese, another movie channel for the television, maybe even a massage from a nubile local, but you don't want to spend it on something you can do your self (or so you think) Get with it and spend the money on something worth paying for...

With every person who carries out his own installation work, we are one more day closer to someone being killed! While I don't like the idea of anyone losing their life I genuinely hope it is the cowboy electrician and not his partner or child...

No matter who it is will you sleep comfy knowing that you helped him along with your expert advice???

Rather you than me Gents, rather you than me...

If you had taken the time to read the OP you would have realized that I'm looking for information to understand what the professional I've hired is doing and to ask him the right question when discussing the house renovation.

So be a man of your word and never post on the subject again.

And on your way out please take this idiot "asdecas" with you.

Thanks

[GTI68]

This has to be the last time I shall post on this subject (not that anyone will give a sh1t:)) as it is now beyond explanation why this still happens and it will always be this way...

I appreciate we are in a third world country when it comes to electrical installations, but why oh why do certain people on TV persist on giving advice to uneducated amateurs?

When back in your "Mother Country" where ever that is, I am sure it is a regulated requirement that a licensed person carry out this work, you know and understand why this is the case so why do you persist in disseminating this information when you know the risks involved?

I have read the replies several times..."It's quite expensive to get someone and it's really quite easy" or "There's just no one available where I live who can do it" or my personal favorite "I've done a lot of research with the drawings posted really quite good"

The bottom line is get your wallets out of your back pocket and pay someone to do it properly, you'll quite happily spend money on grog, your favorite cheese, another movie channel for the television, maybe even a massage from a nubile local, but you don't want to spend it on something you can do your self (or so you think) Get with it and spend the money on something worth paying for...

With every person who carries out his own installation work, we are one more day closer to someone being killed! While I don't like the idea of anyone losing their life I genuinely hope it is the cowboy electrician and not his partner or child...

No matter who it is will you sleep comfy knowing that you helped him along with your expert advice???

Rather you than me Gents, rather you than me...

If you had taken the time to read the OP you would have realized that I'm looking for information to understand what the professional I've hired is doing and to ask him the right question when discussing the house renovation.

So be a man of your word and never post on the subject again.

And on your way out please take this idiot "asdecas" with you.

Thanks

Fair enough.

One small point I might add as to the computer "shocks". Make sure you are also using a 3 pin plug from your computer

into the outlet, otherwise it is not earthed. I know it sounds silly but I have fallen for this myself.

[TheMysteriousMrTesla]

Bignose does have valid points and I'm sure that most of us would happily pay a pro. to do the job.

Problem is finding a pro. who really is professional, licensed, here? Which is of course why our OP posted here.

Plenty of other sites offering electrical help, many based in the US, perhaps he should go there and tell them their expert advice is not wanted.

[Forkinhades]

^ Even with the right equipment

[Crossy]

Thai sparkie's equipment check:-

1. Black tape - check
2. Screwdrivers, one - (with neon tester if he's a real pro.), one + - check
3. Industrial scissors - check
4. Bamboo ladder - borrow from neighbours