Is my fuse box grounded properly?

[Forkinhades]

Please make sure that your village has MEN implemented if you are going to do the N-E connection.

You can of course omit that connection the device will work fine without it.

Can you post a picture of your local transformer (Tx)?

[Gulfsailor]

Please make sure that your village has MEN implemented if you are going to do the N-E connection.

You can of course omit that connection the device will work fine without it.

Can you post a picture of your local transformer (Tx)?

Thanks! No MEN here. At least I couldn't find any grounds on the poles in the street. I will keep a close eye on my sparky when he will install it later in the week. Also a first for him!

Too dark now to make a photo of the transformer, so I drew my favorite one for you in stead. Transformers are cool...

[Forkinhades]

LOL

Sent from my GT-I9300 using Thaivisa Connect Thailand mobile app

[Forkinhades]

Once it is installed, all you need to do is test it.

[Gulfsailor]

Once it is installed, all you need to do is test it.

So. Had the main cut out and safety cut installed today. Looking tidy. I changed most outlets to grounded three prong as well. As for testing the new setup; the group breaker trips when shorting L and N at a random outlet, and the Safe-T-Cut trips when I short L with E at a random outlet. Is there a way to simulate a small (say 30mA) leak, so I can test if the safetcut actually measures correctly? I turned the dial on it to 20mA (range from 6 to 30). At my crappy 200 volt multiplied by 30mA, can I just connect a 6watt light between L and E and safety cut should trip? Whereas using a 3 Watt light it shouldn't trip?

Again, thanks mainly to Crossy and Forkinhades for all the explanations!

[Crossy]

Using a lamp L-E will give you a good idea that it's working, you really need to use resistors to do a proper test as lamps have a non-linear characteristic.

I really wouldn't go around applying dead shorts to a live system, if the breaker doesn't open because of a failure (or it's a fake) the results could be extremely dangerous in an explosive manner.

There is an awful lot of energy available in the grid, even a small transformer can generate fault currents of several thousand Amps, just think what your tiny little short would do with that sort of current flowing!

[thomasteve]

Neat installation judging by the photo. Those 'knife' switch isolators always look scary to me !! Is it possible to touch live contacts if a paper clip or similar was to fall in ?

Follow Crossy's advice and only use the test button to check the safe-t-cut or a proper test device which consists of some resistors to limit the test fault current (see photo).

A direct L-N short can release a lot of unexpected energy / heat and certainly enough to 'fry' a neon screwdriver before the circuit breaker trips.

[Gulfsailor]

IMG-20140117-01084.jpgNeat installation judging by the photo. Those 'knife' switch isolators always look scary to me !! Is it possible to touch live contacts if a paper clip or similar was to fall in ?

Follow Crossy's advice and only use the test button to check the safe-t-cut or a proper test device which consists of some resistors to limit the test fault current (see photo).

A direct L-N short can release a lot of unexpected energy / heat and certainly enough to 'fry' a neon screwdriver before the circuit breaker trips.

Agree that the knife switch is a bit scary. I think I can squeeze my pinky in the slot and touch the copper mechanics. But it is located high enough not to easily happen unless wanted. And I don't plan to hang paper clips on the wall over the switch... But know I think about it, since there is no reason to actually ever open the switch unless I make changes to the safe t cut installation, I will place a cover over it.

To test the breaker and safe t cut I will follow your (and Crossy's) advise and not make any dead short anymore. Anyway everything tripped like it should. And better to find out something is wrong now with the electrician doing it, then finding out a breaker is faulty when an appliance is damaged and makes the dead short.

I have a box of resistors. Is there any voltage max for standard round film resistors? I normally use them for low voltage DC projects. Can I use the same ones on 220AC? I have 4.7K, 6.8K and 10K Ohm ones, so these fit nicely around the 20-40mA range. Plus I have some trimpots lying around. So unless I can find a good tester that also shows cutoff delay time, I will cobble something together using said resistors.

Ps. Great new electric forum here! Been 20 years that I learned most at school and mostly forgotten, but all coming back again now!

[thomasteve]

IMG-20140117-01084.jpgNeat installation judging by the photo. Those 'knife' switch isolators always look scary to me !! Is it possible to touch live contacts if a paper clip or similar was to fall in ?

Follow Crossy's advice and only use the test button to check the safe-t-cut or a proper test device which consists of some resistors to limit the test fault current (see photo).

A direct L-N short can release a lot of unexpected energy / heat and certainly enough to 'fry' a neon screwdriver before the circuit breaker trips.

Agree that the knife switch is a bit scary. I think I can squeeze my pinky in the slot and touch the copper mechanics. But it is located high enough not to easily happen unless wanted. And I don't plan to hang paper clips on the wall over the switch... But know I think about it, since there is no reason to actually ever open the switch unless I make changes to the safe t cut installation, I will place a cover over it.

To test the breaker and safe t cut I will follow your (and Crossy's) advise and not make any dead short anymore. Anyway everything tripped like it should. And better to find out something is wrong now with the electrician doing it, then finding out a breaker is faulty when an appliance is damaged and makes the dead short.

I have a box of resistors. Is there any voltage max for standard round film resistors? I normally use them for low voltage DC projects. Can I use the same ones on 220AC? I have 4.7K, 6.8K and 10K Ohm ones, so these fit nicely around the 20-40mA range. Plus I have some trimpots lying around. So unless I can find a good tester that also shows cutoff delay time, I will cobble something together using said resistors.

Ps. Great new electric forum here! Been 20 years that I learned most at school and mostly forgotten, but all coming back again now!

The tester I pictured uses a resistor of approx. 8k ohms but it is rated at approx. 10 W to pass a current exceeding 30 mA.

The standard carbon ones you have are possibly only rated at around 0.25 Watts so would be unsuitable.

A question for those more familiar with Safe-t-cuts - why is it necessary for the trip current to be adjustable on RCD's in Thailand - I have not come across adjustable RCD's from other manufacturers as they are usually fixed at 20-30 mA.

[Gulfsailor]

IMG-20140117-01084.jpgNeat installation judging by the photo. Those 'knife' switch isolators always look scary to me !! Is it possible to touch live contacts if a paper clip or similar was to fall in ?

Follow Crossy's advice and only use the test button to check the safe-t-cut or a proper test device which consists of some resistors to limit the test fault current (see photo).

A direct L-N short can release a lot of unexpected energy / heat and certainly enough to 'fry' a neon screwdriver before the circuit breaker trips.

Agree that the knife switch is a bit scary. I think I can squeeze my pinky in the slot and touch the copper mechanics. But it is located high enough not to easily happen unless wanted. And I don't plan to hang paper clips on the wall over the switch... But know I think about it, since there is no reason to actually ever open the switch unless I make changes to the safe t cut installation, I will place a cover over it.

To test the breaker and safe t cut I will follow your (and Crossy's) advise and not make any dead short anymore. Anyway everything tripped like it should. And better to find out something is wrong now with the electrician doing it, then finding out a breaker is faulty when an appliance is damaged and makes the dead short.

I have a box of resistors. Is there any voltage max for standard round film resistors? I normally use them for low voltage DC projects. Can I use the same ones on 220AC? I have 4.7K, 6.8K and 10K Ohm ones, so these fit nicely around the 20-40mA range. Plus I have some trimpots lying around. So unless I can find a good tester that also shows cutoff delay time, I will cobble something together using said resistors.

Ps. Great new electric forum here! Been 20 years that I learned most at school and mostly forgotten, but all coming back again now!

The tester I pictured uses a resistor of approx. 8k ohms but it is rated at approx. 10 W to pass a current exceeding 30 mA.

The standard carbon ones you have are possibly only rated at around 0.25 Watts so would be unsuitable.

A question for those more familiar with Safe-t-cuts - why is it necessary for the trip current to be adjustable on RCD's in Thailand - I have not come across adjustable RCD's from other manufacturers as they are usually fixed at 20-30 mA.

The adjustable current dial is to make the whole thing look more impressive. Same goes for the insanely bright LED, stickers galore, an extra 8A fuse which I have no idea what it's for, a triple connecting breaking thingy, and some other cool looking features. How else can they charge so much for it. And why is that thing so enormous!? You can have board plugin RCBOs which are at least 20 times smaller in volume.

[thomasteve]

It's unfortunate that they are so expensive as a scaled down basic version, without all the extra 'features' and sold for a few hundred Baht, would encourage more users to fit them and help to reduce the number of accidental electrocutions.

[Forkinhades]

IMG-20140117-01084.jpgNeat installation judging by the photo. Those 'knife' switch isolators always look scary to me !! Is it possible to touch live contacts if a paper clip or similar was to fall in ?

Follow Crossy's advice and only use the test button to check the safe-t-cut or a proper test device which consists of some resistors to limit the test fault current (see photo).

A direct L-N short can release a lot of unexpected energy / heat and certainly enough to 'fry' a neon screwdriver before the circuit breaker trips.

I was looking in Thai Watsadu, and they had a good range availlable. ABB and Schnieder, and Haco.

The ABB and Schnieder range had Ka ratings of 6, whilst the Haco was only 1.5!! Amazingly they did not stock any Safe-T-Cut (Could not see them anyway)

will echo the above about the L-N short.

[Forkinhades]

Just to add that if you are serious about testing your RCD with the correct equipment then this is what you need.

http://thailand.rs-online.com/web/p/rcd-testers/7125737/

Stand alone RCD tester