C
carlmeek
We own a 2 year old house built in Bangkok as part of a large village. Shortly after moving in, we paid a local guy to upgrade the consumer unit in order to install five air-conditioning units. He advised us how to do this, and installed a Safe-T-Cut RCBO as part of that install. It all looked very professional, so we were happy with the job.
I’d like to install a second electric shower, and after reading many horror stories, i thought i’d investigate the electrics setup to see just how dangerous it all is.
My background - an avid DIY enthusiast in the UK, and i've wired up two new home extensions which were later certified as compliant by an electrician, so i know what i’m doing, and always work within the regs, within the realms of the UK… but this is a bit different!
Attached is a photo of the setup. It took me a while to figure it out, and got more and more horrified as I did!
My observations:
- Earth and Neutral are blended into one! The main cabinet casing, and the outer casing of the Consumer Unit are all connected to Neutral.
- Almost all sockets around the house are 2 pin, so no earth fed to these boxes. There are only 2 green earth feeds, one to the shower, and one somewhere else (no idea where)
- The “neutral bar” of the main cabinet seems to have two feeds in. It’s not isolated from the cabinet, so the main cabinet is therefore neutral. I wonder if one feed is an earth - who knows, they are all black.
- The large 5 breakers in the middle bypass the Safe-T-Cut and feed the 5 A/C units. Whereas the main consumer unit feeds everything else, including electric showers which also have ELCB's built in (which i presume are pointless).
- In other words - There is no earth whatsoever.
- The neutral lines are split - half going to the proper neutral bus in the consumer unit, and half going to what should be the earth bus. Looks like half are the ones in the consumer unit, and half the breakers that are separate from it.
- Supply cables to the house circuits are gray/white and no earth anywhere. Except there are two green cables in there, connected to Neutral.
- Colours appear to be white or green for neutral, grey or blue for live. black for everything that requires a fat wire, with red insultating tape denoting live.
In order to investigate further i decided to remove the consumer unit and look behind it. What i found....
- Lots of "connections" - twisted together wires with insulating tape around. These are extending the previously short wires to a bit longer so they can meet the consumer unit in it's new location. Three are the big black wires, all unlabelled - one live, one neutral (heading upward) and an earth (heading downward). Neutral and earth both connected to the earth bar in the cabinet.
- I disconnected both earth and neutral, after it was switched off at the big switch. I was getting small shocks whilst touching it, and mild sparking when tapping both earth and neutral back onto the bar. It turns out there's a light on the front of the cabinet (a green indicator) that's been connected in on the supply side of the main switch, so is causing current to travel into the neutral line even when isolated.
- So I moved the indicator to the safe side of the switch and stopped getting shocks.
- I then disconnected earth and neutral in turn, and tested to see how it behaved. I found that either being connected "worked" - so current was flowing from live to both neutral and earth lines. I'm Guessing that this is OK - live flows to earth.. but it wasn't quite what i expected. I've never tested this back home in the UK!
- I rewired it to split earth and neutral, using a new connection block to feed neutrals to the A/C bypassing the Safe-T-Cut.
- I replaced twisted together wires with proper block connectors and crimps.
- I turned the safe-t-cut down to 5ma instead of 30ma as it was set before.
- Final problem, and one I cannot think to resolve, is that the neutrals seem to be cross-connected. I disconnected them all, and connected one-at-a-time, testing each circuit. There are 6 breakers, i labelled A-F, and then tried to match neutrals to the breakers. I ended up labelling the neutrals "A&C", "A&C", "B,D,E","B,D,E" and "F". because connecting either of the A&C cables made both A&C breakers live. Same for B&D&E except there are only two cables here making live 3 circuits. Baffling, but i'm guessing there are no proper rings, and things are just connected any-old-how.
- It's all working fine, but then it was before... but hopefully it's slightly less deadly now.
It appears to me, and as i've read before, this guy (and presumably many others) simply don't understand earth at all. The fact that the outer cabinets, and all earth wires, were simply neutral sounds scary to me.
So i think i've done some good, but it's still not perfect. I'm shocked that it can be botched so badly, but then with so many deaths on the roads, who cares about electrics? It would be amusing if it were not so sad and tragic. Its out of context with the house which is stunning and modern.
-C
I’d like to install a second electric shower, and after reading many horror stories, i thought i’d investigate the electrics setup to see just how dangerous it all is.
My background - an avid DIY enthusiast in the UK, and i've wired up two new home extensions which were later certified as compliant by an electrician, so i know what i’m doing, and always work within the regs, within the realms of the UK… but this is a bit different!
Attached is a photo of the setup. It took me a while to figure it out, and got more and more horrified as I did!
My observations:
- Earth and Neutral are blended into one! The main cabinet casing, and the outer casing of the Consumer Unit are all connected to Neutral.
- Almost all sockets around the house are 2 pin, so no earth fed to these boxes. There are only 2 green earth feeds, one to the shower, and one somewhere else (no idea where)
- The “neutral bar” of the main cabinet seems to have two feeds in. It’s not isolated from the cabinet, so the main cabinet is therefore neutral. I wonder if one feed is an earth - who knows, they are all black.
- The large 5 breakers in the middle bypass the Safe-T-Cut and feed the 5 A/C units. Whereas the main consumer unit feeds everything else, including electric showers which also have ELCB's built in (which i presume are pointless).
- In other words - There is no earth whatsoever.
- The neutral lines are split - half going to the proper neutral bus in the consumer unit, and half going to what should be the earth bus. Looks like half are the ones in the consumer unit, and half the breakers that are separate from it.
- Supply cables to the house circuits are gray/white and no earth anywhere. Except there are two green cables in there, connected to Neutral.
- Colours appear to be white or green for neutral, grey or blue for live. black for everything that requires a fat wire, with red insultating tape denoting live.
In order to investigate further i decided to remove the consumer unit and look behind it. What i found....
- Lots of "connections" - twisted together wires with insulating tape around. These are extending the previously short wires to a bit longer so they can meet the consumer unit in it's new location. Three are the big black wires, all unlabelled - one live, one neutral (heading upward) and an earth (heading downward). Neutral and earth both connected to the earth bar in the cabinet.
- I disconnected both earth and neutral, after it was switched off at the big switch. I was getting small shocks whilst touching it, and mild sparking when tapping both earth and neutral back onto the bar. It turns out there's a light on the front of the cabinet (a green indicator) that's been connected in on the supply side of the main switch, so is causing current to travel into the neutral line even when isolated.
- So I moved the indicator to the safe side of the switch and stopped getting shocks.
- I then disconnected earth and neutral in turn, and tested to see how it behaved. I found that either being connected "worked" - so current was flowing from live to both neutral and earth lines. I'm Guessing that this is OK - live flows to earth.. but it wasn't quite what i expected. I've never tested this back home in the UK!
- I rewired it to split earth and neutral, using a new connection block to feed neutrals to the A/C bypassing the Safe-T-Cut.
- I replaced twisted together wires with proper block connectors and crimps.
- I turned the safe-t-cut down to 5ma instead of 30ma as it was set before.
- Final problem, and one I cannot think to resolve, is that the neutrals seem to be cross-connected. I disconnected them all, and connected one-at-a-time, testing each circuit. There are 6 breakers, i labelled A-F, and then tried to match neutrals to the breakers. I ended up labelling the neutrals "A&C", "A&C", "B,D,E","B,D,E" and "F". because connecting either of the A&C cables made both A&C breakers live. Same for B&D&E except there are only two cables here making live 3 circuits. Baffling, but i'm guessing there are no proper rings, and things are just connected any-old-how.
- It's all working fine, but then it was before... but hopefully it's slightly less deadly now.
It appears to me, and as i've read before, this guy (and presumably many others) simply don't understand earth at all. The fact that the outer cabinets, and all earth wires, were simply neutral sounds scary to me.
So i think i've done some good, but it's still not perfect. I'm shocked that it can be botched so badly, but then with so many deaths on the roads, who cares about electrics? It would be amusing if it were not so sad and tragic. Its out of context with the house which is stunning and modern.
-C
