Voltage drops when turning on equipment

[Crossy]

Just now, Moonlover said:

And looking at the final photos that he sent, that's exactly what he found. I hope he's got that mess sorted.

 

I was chatting with a pal last night who oversees bespoke house building work. He was telling me how difficult it is to try and get the electricians to put in a ring main for the sockets.

 

He said they just cannot understand why they have to put two cables to each outlet. .'One is enough. It's always worked ok'.

 

Ways to go!

 

I really, really hope he's not installing ring-finals in Thailand, and particularly not putting them on 32A breakers.

 

[Moonlover]

Just now, Crossy said:

 

I really, really hope he's not installing ring-finals in Thailand, and particularly not putting them on 32A breakers.

 

I didn't go that deep and I'll not bother. It's called retirement. 

[Crossy]

Just now, Moonlover said:

I didn't go that deep and I'll not bother. It's called retirement. 

 

You're happy to let someone install potential fire hazards then?

 

Even countries using BS1363 plugs tend to put them on radials now (including the UK where the ring-final originated).

 

[Moonlover]

3 hours ago, Crossy said:

 

I really, really hope he's not installing ring-finals in Thailand, and particularly not putting them on 32A breakers.

 

Why not?

[Crossy]

10 hours ago, Moonlover said:

Why not?

 

The ring format was devised post-war, maximum amount of floor space covered using the minimum amount of copper. It was decided that 2.5mm² cable was the most economical and if a ring was used you could effectively double the available power at each outlet.

 

UK ring-finals are usually fused (ok breakered) at 32A. The baby flex on most low power appliances (say 0.5mm²) will be well on fire before that breaker even considers opening (it will carry 40A for many minutes). To mitigate this and protect the flex we have BS1363 plugs with a fuse, even a 13A fuse will open rapidly in the event of a short on a 1.5m 0.5mm² flex.

 

So, UK ring, the breaker protects the ring, the plug fuse protects the appliance flex.

 

OK, head over to Thailand. Thai plugs are rated at 16A BUT they have no fuses. So in order to protect the flex and the plug we use a 20A breaker. No need for a ring as 2.5mm² will happily carry 20A+.

 

The 20A breaker protects the cable and the appliance flex.

EDIT It's not perfect, we often hear of fires being started by faulty fans and the like which would likely have opened the plug fuse back home.

 

Now, if we build a ring with a 32A breaker and Thai plugs there's nothing protecting the flex (or the plug) from massive overload (uncle Somchai's welder perhaps) and resulting fire.

 

Most countries outside the UK, even those that use BS1363 plugs (Malaysia, Singapore, Hong Kong etc etc) use 2.5mm² radials on 20A breakers.

 

By the way, in the UK you can get an extra 8A from a ring-final (on a 32A breaker), by converting it into two radials each on a 20A breaker.

 

EDIT 2 More interesting reading https://en.wikipedia.org/wiki/Ring_circuit

 

 

[Forkinhades]

Nicely explained Xy

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[Moonlover]

1 hour ago, Crossy said:

 

The ring format was devised post-war, maximum amount of floor space covered using the minimum amount of copper. It was decided that 2.5mm² cable was the most economical and if a ring was used you could effectively double the available power at each outlet.

 

UK ring-finals are usually fused (ok breakered) at 32A. The baby flex on most low power appliances (say 0.5mm²) will be well on fire before that breaker even considers opening (it will carry 40A for many minutes). To mitigate this and protect the flex we have BS1363 plugs with a fuse, even a 13A fuse will open rapidly in the event of a short on a 1.5m 0.5mm² flex.

 

So, UK ring, the breaker protects the ring, the plug fuse protects the appliance flex.

 

OK, head over to Thailand. Thai plugs are rated at 16A BUT they have no fuses. So in order to protect the flex and the plug we use a 20A breaker. No need for a ring as 2.5mm² will happily carry 20A+.

 

The 20A breaker protects the cable and the appliance flex.

EDIT It's not perfect, we often hear of fires being started by faulty fans and the like which would likely have opened the plug fuse back home.

 

Now, if we build a ring with a 32A breaker and Thai plugs there's nothing protecting the flex (or the plug) from massive overload (uncle Somchai's welder perhaps) and resulting fire.

 

Most countries outside the UK, even those that use BS1363 plugs (Malaysia, Singapore, Hong Kong etc etc) use 2.5mm² radials on 20A breakers.

 

By the way, in the UK you can get an extra 8A from a ring-final (on a 32A breaker), by converting it into two radials each on a 20A breaker.

 

EDIT 2 More interesting reading https://en.wikipedia.org/wiki/Ring_circuit

 

 

Ok. Thank you very much for your time Crossy. As far as I know, my pal never did persuade the 'leckies' to install his much loved ring main. (I've even learned that that is a misnomer today). Perhaps they knew more than he thought.

 

Hey, it's Labour Day. Take a day off. 

[sandyf]

14 hours ago, Moonlover said:

And looking at the final photos that he sent, that's exactly what he found. I hope he's got that mess sorted.

 

I was chatting with a pal last night who oversees bespoke house building work. He was telling me how difficult it is to try and get the electricians to put in a ring main for the sockets.

 

He said they just cannot understand why they have to put two cables to each outlet. .'One is enough. It's always worked ok'.

 

Ways to go!

You cannot write them all off there are good electricians about, the one that did my house was excellent.

 

[sandyf]

1 hour ago, Crossy said:

 

The ring format was devised post-war, maximum amount of floor space covered using the minimum amount of copper. It was decided that 2.5mm² cable was the most economical and if a ring was used you could effectively double the available power at each outlet.

 

UK ring-finals are usually fused (ok breakered) at 32A. The baby flex on most low power appliances (say 0.5mm²) will be well on fire before that breaker even considers opening (it will carry 40A for many minutes). To mitigate this and protect the flex we have BS1363 plugs with a fuse, even a 13A fuse will open rapidly in the event of a short on a 1.5m 0.5mm² flex.

 

So, UK ring, the breaker protects the ring, the plug fuse protects the appliance flex.

 

OK, head over to Thailand. Thai plugs are rated at 16A BUT they have no fuses. So in order to protect the flex and the plug we use a 20A breaker. No need for a ring as 2.5mm² will happily carry 20A+.

 

The 20A breaker protects the cable and the appliance flex.

EDIT It's not perfect, we often hear of fires being started by faulty fans and the like which would likely have opened the plug fuse back home.

 

Now, if we build a ring with a 32A breaker and Thai plugs there's nothing protecting the flex (or the plug) from massive overload (uncle Somchai's welder perhaps) and resulting fire.

 

Most countries outside the UK, even those that use BS1363 plugs (Malaysia, Singapore, Hong Kong etc etc) use 2.5mm² radials on 20A breakers.

 

By the way, in the UK you can get an extra 8A from a ring-final (on a 32A breaker), by converting it into two radials each on a 20A breaker.

 

EDIT 2 More interesting reading https://en.wikipedia.org/wiki/Ring_circuit

 

 

Looks like the electrician that did my house put the sockets on 3 different rings with 20A breakers, there are 2 x 2.5 mm cables in the back of the sockets. Same with the lights been split into different circuits.

[Forkinhades]

^^^^^ Nothing wrong with that. I had my kitchen circuit installed as a ring, but I've got UK plugs, witch are fused down to the relevant appliance. I also used snieder accessories to accept the UK plug.

 

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[Forkinhades]

Point to add though, just because you have 2 cables at a socket, dosnt mean that it's installed on a ring.

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[BEVUP]

37 minutes ago, sandyf said:

You cannot write them all off there are good electricians about, the one that did my house was excellent.

 

Yes had a good sparky like this before, not like the crap i have in a new Moo Baan now 

No wonder the developer kicked him out & nothing was straight 

Then when you see this beautiful work above along comes the aircon installer & cracks open every junction box trying to fin a cable to twist into (happened to a bloke i know) 

[Forkinhades]

In my main living quarters I also got this grid switch fitted. The 6 switches control certain sockets. Media Centre, IT centre, and other plugs.

These little beauties are also installed to protect against spikes, and will protect my electronic and sensitive equipment. (Thanks Xy for them)

Also have the sockets fused down, as you can see on the bottom tight of 1st picture. Protected by 20Amp MCB upstream, and an 30mA RCCB upstream of that.

MEN link also installed, and now have TN values at the incoming supply.

 

 

 

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[sandyf]

10 minutes ago, BEVUP said:

Yes had a good sparky like this before, not like the crap i have in a new Moo Baan now 

No wonder the developer kicked him out & nothing was straight 

Then when you see this beautiful work above along comes the aircon installer & cracks open every junction box trying to fin a cable to twist into (happened to a bloke i know) 

Quite. One of the benefits of doing it yourself, I had already positioned the AC units and the electrician run cables to boxes in the wall for AC connection. It was about 2 years before all 3 were fitted. Same in the bathrooms, had cable run in to the 2 bathrooms for an electric shower, although I have only fitted the one.

The electrician also put in, at his suggestion, wires for a door bell. I have not used those, got a wireless version instead.

[Roeland]

Hi guys,

 

Sorry for the late update but everything is fixed now (according to thai standards that is)

I went to MEA myself and after showing the pictures they responding quite quickly by showing up the next day.

 

Luckily I was there because after they "tested" the output with their voltage meter he smiled at me showing me the 225V and said Power OK. 

In my best Thai I told him to wait as I turned on the hot shower. He realised the power was NOK and called his backup sqaud. 

They ended up coming the next day to make all new connections on the main power lines. 

 

Now I can switch on AC's, hot showers without even a small voltage drop noticeable.

All the connections where just very badly corroded/damaged which caused the problems. 

 

Thanks for the help guys, appreciate the support.

 

[Crossy]

Result!

 

Thanks for the update.