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ilikethai

electricity meter and CB, please settle

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I'm not an electrician but the local pros are many times wrong.  Anyway, did a 9 hr travel to a friend's place and trying to help with his rewire for his house and a small shop but instead we decided to hire a local.  got into a heated argument with a "pro" electrician.  Anyway here is the current house set up and the pro said it's fine and wouldn't want to redo it:

3/9 meter 220v---> av25 7s/1.7mm 0.6/1kv (assuming this is the size?) black aluminum wire------->connected to a metal clamp and into a copper 4mm size------->into Voltage stabilizer with 50a builtin breaker, earthed----------> then out into 2.5mm copper size into a 60a MCB black very old looking square breaker-------> out to 2 sockets (outlets) 1.5mm wire size combine with 4 lights--------> (from 60a MCB) 2.5mm wire to kitchen socket and 2 pairs of lights (1 switch control 2 lights)--------->(from 60a MCB) 2.5mm wire to 30a CB dedicated for water heater then it taps out into another 30a CB for the fridge and sockets------->(from 60a MCB) to 30a with 2.5mm copper wire into a socket combined with 3 lights then taps out into another 30a with 1.5mm (yes) copper wire solely for AC 10,000btu

 

the shop:

5/15 meter 220v ------>straight from the meter with 2.5mm copper wire into 30a CB for 4 lights low wattage, 1 fan, 1 socket------>tap out to 30a CB with 2.5mm copper wire for 4 lights, 1 fan, 1 socket------>straight from meter with 4mm copper wire into 30a CB for a med size 2 doors beverage showcase cooler (it says 5.6amp on the inside spec sticker but I don't think it's that much or I'm wrong) and earthed the cooler with copper rod with 2.5mm copper wire.

 

Also he demanded that the L and the N wire must pass through the MCB and the same into all the small CB's L and N slots.  Should it be better if  L and N wire from meter all go into both of the MCB slots first, then from MCB out divert the N wire into a dedicated bus bar in the distribution box and all the CB's N wires into the same bus bar?  Does it matter?

 

if the meter says 5/15 220v would it be better to match it with a 15a breaker or even a 20a breaker instead of a whopping 60a breaker?

 

Is ELCB breaker a must to be put between the MCB and the smaller CB's?  Or should this ELCB breaker be put between the meter and the MCB?

 

Sorry very confusing. Thankful in advance

Edited by ilikethai

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Your explanation of the setup looks as if there is some kind of code involved so is horribly difficult to understand, your abbreviations are not standard.

 

However yes the in coming  main breaker should be lower than 60A

 

I couldn't workout the sizes of the in coming wires and the breaker should match them, the meter will probably supply at least 30A without problems, but will not be accurate.

 

 

 

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I think we are going to need some photos here.

 

Small breakers with L and N connections could well be RCBOs in which case they will need both L and N feeds.

 

A 5/15 should be fine with a main breaker of 30A, anything larger after that is not relevant. 

 

 

 

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thanks for the fast reply.  Let's just say #1 meter is 3/9 how would I go from here, it needs to power 10,000 btu AC, water heater, small electric cooker, rice cooker, about 12 lights, 5 sockets?

 

#2 meter is 5/15 and how would I from here, it needs to power the cooler 5.6amp, 8 low wattage lights, 2 sockets?

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I don't understand "#1 meter is 3/9" for starters.

 

We really do need photos.

 

I'm assuming we have two installations here, one for the shop on a 5/15 and one for the house on a separate meter - am I right here?

 

The shop should be easy. 5/15 => 30A main breaker => assorted sub breakers for the circuits. Wired like the diagram above.

 

EDIT Important, are you in Thailand?

 

 

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42 minutes ago, Crossy said:

I don't understand "#1 meter is 3/9" for starters.

 

We really do need photos.

 

I'm assuming we have two installations here, one for the shop on a 5/15 and one for the house on a separate meter - am I right here?

 

The shop should be easy. 5/15 => 30A main breaker => assorted sub breakers for the circuits. Wired like the diagram above.

 

EDIT Important, are you in Thailand?

 

 

2 separate installations and locations, 1 for his home and 1 for his shop. 

For the shop but then wouldn't a 30A main breaker be too much from a 15A meter, I know we can stretch it but just to be on the technical safe side.  I was thinking 20A main breaker and then branch it out into 10A breakers.

 

I don't really know if photos would help because they're all over the places.  I attached pics of MCB and the CB's.  Over at his place they wire both the L and N wires to the CB and then out see pics.  In Southern BK where I'm staying they do meter, both L and N wire into main breaker then out from main breaker L and N and into sub breakers but only the L (hot) wires go through the sub breakers and the N (neutral) wires all go into the bus bar.

20191017_180617.jpg

20191017_181027.jpg

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1 hour ago, ilikethai said:

thanks for the fast reply.  Let's just say #1 meter is 3/9 how would I go from here, it needs to power 10,000 btu AC, water heater, small electric cooker, rice cooker, about 12 lights, 5 sockets?

 

As crossy has said that does not make any sense for Thailand.

 

However the load will not be more than a 5/15 meter will handle, assuming the water heater isn't too big. Though for a better answer. What is the power of the water heater and how long is it switched on? 

 

FWIW the 5 sockets don't use power 😉 but if your going to be plugging more stuff in it will.

 

The 60A is doing nothing and will probably never trip. It should protect the wires from starting fires and it won't.

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Actually, I'm guessing here, there may be no consumer unit at all, just a lot of things wired directly from the meter all going through that 60 amp circuit breaker then to double pole switches that are being called circuit breakers like the 2 in the bottom picture.

 

They have no trip rating the 30A is just the power that they can carry and being called a safety breaker doesn't make them a circuit breaker, except in the sense that any switch breaks a circuit!

 

@ilikethai is there anything that looks remotely like this?

IMG_8538.thumb.JPG.aac01474f042039c72914f815db6f306.JPG

Edited by sometimewoodworker

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6 minutes ago, sometimewoodworker said:

As crossy has said that does not make any sense for Thailand.

 

However the load will not be more than a 5/15 meter will handle, assuming the water heater isn't too big. Though for a better answer. What is the power of the water heater and how long is it switched on? 

 

FWIW the 5 sockets don't use power 😉 but if your going to be plugging more stuff in it will.

 

The 60A is doing nothing and will probably never trip. It should protect the wires from starting fires and it won't.

Ok What I will tell the pro is this.  5/15 meter out with 4mm copper wire with L and N wire both into 20A Main Breaker (I call this MCB), I will Earth it from here,  then out 2.5mm copper with only L (hot) wire into a sub breaker 10A (I call this CB) but the N (neutral) wire into busbar (neutral bar).  10A with 2.5mm wire solely for AC and Earth it.  10A solely with 2.5mm wire water heater just found out it's 3500W Panasonic heater.  10A or smaller for the rest of each point. 

 

the 3/9 meter I will do the same as like above and making the MCB as the distributor breaker branching out into smaller breakers. 

 

Basically I will make sure the MCB (main breaker) amp is matching or a little higher amp, say 15A for the 3/9 meter and 25A or 30A for the 5/15 meter? I will also match or try to over match my AC breaker, heater breaker, etc.  Right?

 

Clarify my friend's house and shop are in Laos.  I'm from BKK.

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1 minute ago, ilikethai said:

Ok What I will tell the pro is this.  5/15 meter out with 4mm copper wire with L and N wire both into 20A Main Breaker (I call this MCB), I will Earth it from here,  then out 2.5mm copper with only L (hot) wire into a sub breaker 10A (I call this CB) but the N (neutral) wire into busbar (neutral bar).  10A with 2.5mm wire solely for AC and Earth it.  10A solely with 2.5mm wire water heater just found out it's 3500W Panasonic heater.  10A or smaller for the rest of each point. 

 

the 3/9 meter I will do the same as like above and making the MCB as the distributor breaker branching out into smaller breakers. 

 

Basically I will make sure the MCB (main breaker) amp is matching or a little higher amp, say 15A for the 3/9 meter and 25A or 30A for the 5/15 meter? I will also match or try to over match my AC breaker, heater breaker, etc.  Right?

 

Clarify my friend's house and shop are in Laos.  I'm from BKK.

I think you have no circuit breakers at all, apart from the 60A one.

 

You just have switches like this one.IMG_8540.thumb.JPG.dab729e46f5436fc2c9e15738beae062.JPG

 

is that that what you have?

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10 minutes ago, sometimewoodworker said:

Actually, I'm guessing here, there may be no consumer unit at all, just a lot of things wired directly from the meter all going through that 60 amp circuit breaker then to double pole switches that are being called circuit breakers like the 2 in the bottom picture.

 

@ilikethai is there anything that looks remotely like this?

IMG_8538.thumb.JPG.aac01474f042039c72914f815db6f306.JPG

yep!  but these "switches" are blocks like pics I provided.  It's like this:  Meter outside at the pole, to "Main Breaker" 60Amp (pic provided) in a living room  then to a smaller "breaker" or you call it "switch" 30Amp in a different room, etc.

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2 minutes ago, sometimewoodworker said:

I think you have no circuit breakers at all, apart from the 60A one.

 

You just have switches like this one.IMG_8540.thumb.JPG.dab729e46f5436fc2c9e15738beae062.JPG

 

is that that what you have?

yes sir/mame!  over in this place they call them "breaker" or "circuit breaker".  So what does a "switch" 15Amp pic you provided and a "breaker" 60Amp pic I provided do?  Now I'm confused.  Time for me to go have a beer

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51 minutes ago, ilikethai said:

yes sir/mame!  over in this place they call them "breaker" or "circuit breaker".  So what does a "switch" 15Amp pic you provided and a "breaker" 60Amp pic I provided do?  Now I'm confused.  Time for me to go have a beer

 @Crossy will know exactly what they are I could be completely wrong and they are just surface mount units like these circuit breakers.

IMG_8541.thumb.JPG.18ebf28598bd417bb3da2d99cef99e34.JPG

that go into a consumer unit.

 

I don't particularly want to open the one I have to check as I'm going to install it soon and I might just let the magic smoke out. 😉 

 

Anyway unless someone knows the Lao meter names you probably need a picture of the 3/9 meter as the current rating will be on it together with an estimate of the wire size (it may be printed on the wires) coming from it into your 60A circuit breake.

 

I think I've reached my level of safe knowledge now.

 

EDIT I've just proved that with the Chang breakers I may have exceeded it, see under 🤣

 

I lied, I've just opened one (no magic smoke release) they do function in a similar way to the ones in a regular CU 

IMG_8543.thumb.JPG.d15547b0275d0dcbea206ea767c32ddb.JPG

 

I don't know how much current has to pass through them for the heated metal strip to trigger, certainly more than the rating. So these need to match the size of the cables feeding them. The guidelines are here

 

The thing you seem to be missing (unless that 60A unit is one from the French system) is an RCCB 

 

Edited by sometimewoodworker
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19 minutes ago, sometimewoodworker said:

 @Crossy will know exactly what they are I could be completely wrong and they are just surface mount units like these circuit breakers.

IMG_8541.thumb.JPG.18ebf28598bd417bb3da2d99cef99e34.JPG

that go into a consumer unit.

 

I don't particularly want to open the one I have to check as I'm going to install it soon and I might just let the magic smoke out. 😉 

 

Anyway unless someone knows the Lao meter names you probably need a picture of the 3/9 meter as the current rating will be on it together with an estimate of the wire size (it may be printed on the wires) coming from it into your 60A circuit breake.

 

I think I've reached my level of safe knowledge now.

 

EDIT I've just proved that with the Chang breakers I may have exceeded it, see under 🤣

 

I lied, I've just opened one (no magic smoke release) they do function in a similar way to the ones in a regular CU 

IMG_8543.thumb.JPG.d15547b0275d0dcbea206ea767c32ddb.JPG

 

I don't know how much current has to pass through them for the heated metal strip to trigger, certainly more than the rating. So these need to match the size of the cables feeding them. The guidelines are here

 

The thing you seem to be missing (unless that 60A unit is one from the French system) is an RCCB 

 

thank you so much.  it's pretty scattered when it comes to electricity here compare to back home BKK.  You're right I need some sort of Safty T Cut between the main breaker and the sub breakers. 

 

Again, please clarify, my old head is thick, so it's safe to go over Amp with the main breaker even though the meter 3/9 is outputting 1980watts right ( was told 9x220v=w)?

The sub breakers should be no more than 20 amp each device(s) point/room or dedicated device?

 

The 5.6amp beverage cooler needs 10A sub breaker, right?  Any breaker higher say 20A it will not trip unless the current pass the 20A mark?  So 10A breaker is good because it will only allow 10 amp to come into the cooler?

 

Since I will recommend my friend to have a distribution box please correct this--->

only the L (hot or live) wire needs to pass the sub breaker and the N (neutral) wire needs to go to bus bar, correct?

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