Electrical Basics Revisited

[Gouldian]

Hi guys,

Just wanted to share my experience, recently I bought a digital-timer from Iwarna. After connecting all equipments to the timer, I experienced some electrical leakage from the lighting retrofit where it was place.

After islolating the equipments 1 by 1, I realized the problem lies with the timer. I suspected it could be due to the fact that I have connected the German Schuko plug direct to our 3 pin socket with the normal 2 pin plastic adaptor resulting in no grounding.

Not intending to cut the timer's wire in order to change plug, i went around looking for Schuko adaptor with grounding to no avail. Until I went to this hardware shop near Novena. Although the uncle do not have the adaptor I needed, he asked the reason for searching for the adaptor.

He suggested me to turn the plug the other way around when inserting into my socket after I completed telling him my story.

Once I reached home, I tried and it work!!! How come??? Just now did some search and realized that its a basic electrical problem called "Reverse Polarity". Although reverse polarity will not present a safety hazard. There are, however, some sensitive electronics and surge protectors that could potentially be affected.

HTH

[kareen]

Do u mean the two pin plug? If there is leakage then turn and plug the opposite way?

[yooyoo99]

Is there any way we can know which is the correct direction for the 2-pin plug without getting the 'shock' first?

Very good tip.....

[Gouldian]

Dear all,

What I have shared is just a solution to my unique problem. It is NOT the solution to all electrical leakage problems. For those who are not savvy its better to get an electrician's advise - I still can remember the pain of my charrred hand.

Anyway for the benefits of all, herewith are some additional information on my particular situation:

"Some plug/socket combinations are designed in a way that a plug can be inserted only one possible way — this is referred to as a polarized plug (not to be confused with positive and negative polarity). Others allow the plug to be inserted with live and neutral either way round — this is referred to as an unpolarized plug. Furthermore even if live and neutral can only connect one way, in some countries it is common to wire them without regard for which is which. This will be hazardous with equipment that connects the neutral to the case.."

Source: http://en.wikipedia.org/wiki/Domestic_AC_p...s#Live_or_Phase

Other useful link:

http://www.rvtravel.com/publish/shock_02.shtml

http://www.workplacegroup.net/articles/art...t-inst-viol.htm

http://www.doityourself.com/stry/upgradeelectrical

http://www.internationalconfig.com/wwpts/index.asp

HTH

[Gouldian]

Do u mean the two pin plug? If there is leakage then turn and plug the opposite way?

Hi Kareen,

Not all problems can be solved with the above only when its been identified as reverse polarity.

HTH

[Gouldian]

Is there any way we can know which is the correct direction for the 2-pin plug without getting the 'shock' first?

Very good tip.....

Hi Yooyoo99,

There are equipments used to test reverse polarity, check on my post above for more info.

HTH

[kareen]

wah... Gouldian... very complicated.... how can a simple digital timer run into electrical leakage problem identify by reverse poraliity....

[Gouldian]

wah... Gouldian... very complicated.... how can a simple digital timer run into electrical leakage problem identify by reverse poraliity....

Hi Kareen,

I suspect the answer lies here:

"Some plug/socket combinations are designed in a way that a plug can be inserted only one possible way — this is referred to as a polarized plug (not to be confused with positive and negative polarity). Others allow the plug to be inserted with live and neutral either way round — this is referred to as an unpolarized plug. Furthermore even if live and neutral can only connect one way, in some countries it is common to wire them without regard for which is which. This will be hazardous with equipment that connects the neutral to the case.."

Source: http://en.wikipedia.org/wiki/Domestic_AC_p...s#Live_or_Phase

HTH

[kareen]

Hi Kareen,

I suspect the answer lies here:

"Some plug/socket combinations are designed in a way that a plug can be inserted only one possible way — this is referred to as a polarized plug (not to be confused with positive and negative polarity). Others allow the plug to be inserted with live and neutral either way round — this is referred to as an unpolarized plug. Furthermore even if live and neutral can only connect one way, in some countries it is common to wire them without regard for which is which. This will be hazardous with equipment that connects the neutral to the case.."

Source: http://en.wikipedia.org/wiki/Domestic_AC_p...s#Live_or_Phase

HTH

yeah... understand that.... I think this unique problem arise from "connected the German Schuko plug"....

[babareef]

Hi guys,

Just wanted to share my experience, recently I bought a digital-timer from Iwarna. After connecting all equipments to the timer, I experienced some electrical leakage from the lighting retrofit where it was place.

After islolating the equipments 1 by 1, I realized the problem lies with the timer. I suspected it could be due to the fact that I have connected the German Schuko plug direct to our 3 pin socket with the normal 2 pin plastic adaptor resulting in no grounding.

Not intending to cut the timer's wire in order to change plug, i went around looking for Schuko adaptor with grounding to no avail. Until I went to this hardware shop near Novena. Although the uncle do not have the adaptor I needed, he asked the reason for searching for the adaptor.

He suggested me to turn the plug the other way around when inserting into my socket after I completed telling him my story.

Once I reached home, I tried and it work!!! How come??? Just now did some search and realized that its a basic electrical problem called "Reverse Polarity". Although reverse polarity will not present a safety hazard. There are, however, some sensitive electronics and surge protectors that could potentially be affected.

HTH

Hi Bro I'm having an electric surge on my water in the sump and main display. How you trace one by one without getting shocked first? Or do u know of any marine electrician around ?

Thanks.

[Gouldian]

Hi Bro I'm having an electric surge on my water in the sump and main display. How you trace one by one without getting shocked first? Or do u know of any marine electrician around ?

Thanks.

Hi Bro,

What you meant by electrical surge?

Do you mean when you hand touches the water, you experience electric shock? If that's the case, try to off 1 electrical appliances at a time and see whether you still get the shock. Usually the culprit is submerged pump with earthing i.e. with 2 pin plugs.

If the shock feel very strong, try to use a test pen rather than dipping your hand into water.

HTH

[babareef]

Thanks Bro. Will try out now.

[Gouldian]

Thanks Bro. Will try out now.

Hi bro,

Do note that when using test pen, always place your index finger on the metal at tip of the pen in order to complete the circuit.

Also, when your test pen does not light up it is not 100% that you do not have stray current.

HTH

[Achilles Tang]

Very good information... thanks Gouldian!

[Gouldian]

Very good information... thanks Gouldian!

Hi AT,

Nothing big deal, just sharing my humble experience.

[iantoh]

thanks for that wonderful bit of info bro gouldian!! i just learned something new!

[babareef]

Hi bro,

Do note that when using test pen, always place your index finger on the metal at tip of the pen in order to complete the circuit.

Also, when your test pen does not light up it is not 100% that you do not have stray current.

HTH

Thanks very much bro. Now I'm still not sure which equipment causing the current. I've switched them off one by one- they are all placed on a extension power cable. So maybe the extension cable is faulty and causing the surge. Every equipment when switched on lighted up my test pen. All these equipments are in my sump and somehow I suspect the extension cable holding them came into contact with water.

I got no time to continue testing all the equipments-need to rush to work. Also haven't tested my chiller plus one or two equipments which are outside the sump. What I've find out is that the main display tank also got electric current. I have 3 pumps in the main tank used for circullation.

Will continue again tonight. Thanks for the advise.

[reeftask]

Thanks very much bro. Now I'm still not sure which equipment causing the current. I've switched them off one by one- they are all placed on a extension power cable. So maybe the extension cable is faulty and causing the surge. Every equipment when switched on lighted up my test pen. All these equipments are in my sump and somehow I suspect the extension cable holding them came into contact with water.

I got no time to continue testing all the equipments-need to rush to work. Also haven't tested my chiller plus one or two equipments which are outside the sump. What I've find out is that the main display tank also got electric current. I have 3 pumps in the main tank used for circullation.

Will continue again tonight. Thanks for the advise.

you must plug off, not only switch off. Best plug in one by one direct to test where is the fault comes from. Usually I dont use test pen as test pen only detects above 80Vac and test pen dont detect current but detects voltage. Small voltage like telephone line still can shock you and still not detected by test pen. I usually use multimeter to be safer.

[babareef]

Thanks to bros reeftask and gouldain and thc, I think I found the culprit. Its the red sea wavemaster pro which has 3 dymax pumps that I used for circulation. So its either the wavemaster, or any of the pumps that caused the leakage. According to bro reeftask usually its the pumps. Will test for that tomorrow. But I don't have a multimeter, only use test pen. Anyway what a relief!

Thanks for all the kind attention especially bro reeftask for patiently waited a few hours while I did the tests.

[reeftask]

Thanks to bros reeftask and gouldain and thc, I think I found the culprit. Its the red sea wavemaster pro which has 3 dymax pumps that I used for circulation. So its either the wavemaster, or any of the pumps that caused the leakage. According to bro reeftask usually its the pumps. Will test for that tomorrow. But I don't have a multimeter, only use test pen. Anyway what a relief!

Thanks for all the kind attention especially bro reeftask for patiently waited a few hours while I did the tests.

If there is a real needy help, I will sure to help. If you need to borrow a multimeter, just let me know. I have few stand-by for my job. I even have an oscilloscope for detecting component level.

[babareef]

That will be great bro reeftask! I'll contact u soon. Oh how can I ever thank you

[reeftask]

no, prob.

[REEFSHARK]

two pin plugs(ac) can be plug in any direction coz no polarity...think bro electrical problem is coz of polarity difference (oversea plug) normally ac have no polarity.

[reeftask]

two pin plugs(ac) can be plug in any direction coz no polarity...think bro electrical problem is coz of polarity difference (oversea plug) normally ac have no polarity.

Is this a comment? answer? or others? I just dont understand. Surrenders.

Please kindly explain again.

[Gouldian]

two pin plugs(ac) can be plug in any direction coz no polarity...think bro electrical problem is coz of polarity difference (oversea plug) normally ac have no polarity.

Dear Reefshark,

Type C Euro Plug do not have polarity thus they can be plug regardless of direction.

As posted earlier there are some plugs that have polarity differences:

"Some plug/socket combinations are designed in a way that a plug can be inserted only one possible way — this is referred to as a polarized plug (not to be confused with positive and negative polarity). Others allow the plug to be inserted with live and neutral either way round — this is referred to as an unpolarized plug. Furthermore even if live and neutral can only connect one way, in some countries it is common to wire them without regard for which is which. This will be hazardous with equipment that connects the neutral to the case.."

Source:

http://en.wikipedia.org/wiki/Domestic_AC_p...s#Live_or_Phase

http://www.internationalconfig.com/standards.asp

HTH