Thailand transformer opinions please. | Page 2 | on ElectriciansForums

Thailand transformer opinions please.

Post new thread

Discuss Thailand transformer opinions please. in the UK Electrical Forum area at ElectriciansForums.net

La Poste

La Poste

-
Joined
Feb 24, 2010
Messages
992
Reaction score
126
Location
South east
Ok here's a few pictures of my mates transformer that supplies his property, his property is in northern Thailand.

[ElectriciansForums.net] Thailand transformer opinions please.[ElectriciansForums.net] Thailand transformer opinions please.[ElectriciansForums.net] Thailand transformer opinions please.


I know the pictures are not great but the tranny doesn't look like it has an earth.
If it has no earth what would members suggest doing to make it safer?
I was thinking:

1. Rod the neutral at the property end to keep the neutral at a safe voltage.
2. Wire the place as normal and then put in a separate earth rod at a certain distance from the neutral rod.
3. RCD or RCBO everything.

I was thinking of installing two rods, one for the neutral and one for the earth so that in the event of say a lost neutral (I'm not a scare monger) the voltage on the metalwork would not jump up, I think a lost neutral in this part of the world is a probable occurrence what with storms and overhead lines.

Does this sound good to people, does this sound like a sensible approach?
Are there any inherent dangers in this approach?
Am I on the right track?

Comments appreciated.

Thanks.
 
Sort by date Sort by votes
its a bit of a mess tony!
the new buildings have much better wiring supplys but the general ovehead suppys are terrible
there are power cuts when it rains heavily, in the rainy season thats most days
i would have liked to photograph other dangerous stuff but didn,t, as the owners of various premises might not have liked me doing that!
these2 reports are the top of the iceberg, i know of one man that was elecrocuted when he touched the fridge
and a little aussie boy when he plugged in his computer game after he left the pool and was wet
Phuket NEWS: Phuket tourist electrocution sparks probe, safety bli

Briton's electrocution in Phuket was an accident, says court ruling
 
Upvote 0 Downvote
Engineer54 said:
I can't see how the neutral can't be earthed at the TX, otherwise the neutral point will be all over the place unreferenced!!
Click to expand...

The voltage is referenced to it’s self. In testing we always used either – or L2 for our earth free systems, it’s not referenced to earth it just a convenient way for us to record readings. We had both AC and DC systems.
Earth faults are a major headache, you don’t know they are there until you’ve got two of them on opposite lines. Durham mentioned the way ship bourn systems worked a while ago, I think it was similar to what we used.
View attachment 15139

If you want earth leakage detection then it gets complicated, the system we used for the 660V AC system used DC injection through chokes. It was a pain in the backside, it would trip at 20mA on a 2.6MW system.
 
Last edited by a moderator:
Upvote 0 Downvote
Great stuff thanks for the replies.

So if I was not sure whether a TX was earthed how would I test this?

Would it be a good idea to bang a nice long rod in and then do a live loop test between supply line and the rod, if I got no reading or infinite resistance would that show the TX was not earthed?

What about taking a voltage measurement between the neutral conductor (assuming it's marked) and true earth?

Is there a method of testing to see whether a TX is earthed or not?
 
Last edited:
Upvote 0 Downvote
Tony said:
The voltage is referenced to it’s self. In testing we always used either – or L2 for our earth free systems, it’s not referenced to earth it just a convenient way for us to record readings. We had both AC and DC systems.
Earth faults are a major headache, you don’t know they are there until you’ve got two of them on opposite lines. Durham mentioned the way ship bourn systems worked a while ago, I think it was similar to what we used.
View attachment 15139

If you want earth leakage detection then it gets complicated, the system we used for the 660V AC system used DC injection through chokes. It was a pain in the backside, it would trip at 20mA on a 2.6MW system.
Click to expand...

Not sure how that would work on a distribution system covering several consumers, with different loads on different phases... And as you say RCD's (which they use in abundance) wouldn't functioning to well.
 
Upvote 0 Downvote
[ElectriciansForums.net] Thailand transformer opinions please.[ElectriciansForums.net] Thailand transformer opinions please.[ElectriciansForums.net] Thailand transformer opinions please.

Here's a few more cropped images of the TX, it does look like at least one cable has been anchored to the pole by means of a bolt.

Maybe this is evidence of the steel within the pole being used as an earth.

I like the tap at the bottom of the TX, I've never seen one of those before.
 
Upvote 0 Downvote
Looks like that's the mystery solved. I'll admit, I'd never have thought of using the poles reenforcing as an Ufer earth.

PS the tap, all oil filled transformers have them. Usualy with a bung fitted. They are especialy designed for numb-nuts elecricians mates to leave part open, as i found out in the middle of the night when half the works shut down. 20MVA transformers don't like running low on oil.
 
Upvote 0 Downvote

Reply to Thailand transformer opinions please. in the UK Electrical Forum area at ElectriciansForums.net

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

YOUR Unread Posts

This website was designed, optimised and is hosted by untold.media Operating under the name Untold Media since 2001.
Back
Top