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ilikethai

electricity meter and CB, please settle

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2 minutes ago, ilikethai said:

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?

You are asking questions that are better answered by someone who is more familiar with that kind of setup. 

 

However that 60A unit unless it's an RCCB (safe-T-cut) needs to go and be replaced by something smaller as it will never trip and almost certainly is too big for the cables.

 

The setup that is in place could be usable. The circuit breakers are there to protect the wires not the things running, a 10A breaker will probably allow 15A for hours and bigger currents for a shorter period.

 

With big wires you can always use smaller SMMCBs (surface mount miniature circuit breakers) but it's always the wires that are protected. With the SMMCBs you need both line and neutral (the neon needs that. In a CU it's only the line that goes through.

 

What problems are there? Or is it just to be safer?

 

If just to be safer then, subject to correction, an RCCB or two ( one for each meter) and probably resizing the SMMCBs to match the size of wire that they are on could be the answer, certainly  cheaper that fitting a modern CU. the benefit would be that the local Sparks will understand and be able to maintain it. 

 

You have talked about a voltage stabiliser but we haven't seen it yet, still waiting on the pictures of the meter and the cable sizes.

 

TTFN

 

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OK Things are much clearer now. Those "safety breakers" are indeed MCBs and will trip at something like 120% of rated current. Do feed both L and N through them as they don't all have the over-current protection on both poles.

 

Your 3500W heater will pull about 16A so should really be on a 20A breaker.

A 12000 BTU A/C will be using around 6A.

 

You can make things a lot safer, particularly around the water heater by replacing the existing 2-pole breakers with RCBOs. You can get ones that are the same form-factor for about 350Baht. Just ensure that the line (supply) and load ends are the correct way round.

 

Don't forget to ground the water heater, bash in a rod nearby if there's no rod currently in use.

 

If you do replace the existing system with a pukka distribution board (consumer unit) it will come with instructions, but yes the incoming supply goes to the 2-pole main breaker then the neutral goes to the neutral bar where all the circuit neutral also go. 

IMPORTANT If you buy the CU in Thailand it will show the incoming neutral wired to the ground bar first before going to the main breaker. This is the Thai way of wiring for MEN. I would suggest NOT wiring this way in Laos unless the local sparks says yes. I don't know if MEN is implemented by the supply authority.

 

EDIT @sometimewoodworker the 60A unit is not an RCD / RCCB but could be replaced by one of the little surface mount RCBOs, that would make things a lot safer at minimal cost.

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7 hours ago, sometimewoodworker said:

You are asking questions that are better answered by someone who is more familiar with that kind of setup. 

 

However that 60A unit unless it's an RCCB (safe-T-cut) needs to go and be replaced by something smaller as it will never trip and almost certainly is too big for the cables.

 

The setup that is in place could be usable. The circuit breakers are there to protect the wires not the things running, a 10A breaker will probably allow 15A for hours and bigger currents for a shorter period.

 

With big wires you can always use smaller SMMCBs (surface mount miniature circuit breakers) but it's always the wires that are protected. With the SMMCBs you need both line and neutral (the neon needs that. In a CU it's only the line that goes through.

 

What problems are there? Or is it just to be safer?

 

If just to be safer then, subject to correction, an RCCB or two ( one for each meter) and probably resizing the SMMCBs to match the size of wire that they are on could be the answer, certainly  cheaper that fitting a modern CU. the benefit would be that the local Sparks will understand and be able to maintain it. 

 

You have talked about a voltage stabiliser but we haven't seen it yet, still waiting on the pictures of the meter and the cable sizes.

 

TTFN

 

here is the stabilizer.  When everything is off the right display it's always at around close to 10.

20191018_051320.jpg

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ok, here are the pics of his home meter and AC.  Please tell as much as possible what those important #'s mean.  20amp or 30amp main breaker for the 3/9 meter will be good size, right?  The RCCB (safe T cut or whatever) can be 30amp because I was told by the Spark any lower then 30amp they do not have them here unless I go with a different brand then maybe a 20amp RCCB. 

 

Conclusion and clarification; 

1. The main breaker can be a little over like 150% of the meter amp. 

2. The RCCB breaker can be a little over the main breaker.

 

I will definitely tell Spark to change the wires to proper size.  There are 1.5mm sq copper and a 2.5mm sq copper coming out from the shop meter.  It should be like only one double wire like a 16mm sq or bigger copper wire.

 

Also his shop roof is aluminum, so I will definitely tell Spark to run the main wire (from meter) using yellow pvc pipe.

20191018_063216.jpg

20191018_063533.jpg

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4 minutes ago, Crossy said:

Is there any way to get the house meter upgraded to a 5/15? At least that wouldn't be oveloaded by the water heater alone.

 

Whilst electricity meters are very tough (a 100% overload won't blow it up) they can become inaccurate when overloaded and you can bet they don't read low.

 

Just talked to the Spark, he said the 3/9 meter should give out about 4,000 watts that's like 2x or 200%. 

"inaccurate" you mean at the expense of $$$?  So when they're stressed out they will read "higher" and we'll be paying more for electricity? 

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2 minutes ago, ilikethai said:

So when they're stressed out they will read "higher" and we'll be paying more for electricity? 

 

Pretty much, yes.

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@Crossy while I understand that what is in place is not OK practice in many places as most want everything to be in a Consumer unit. If the correct value surface mount RCBOs and surface mount MCBs are in place, wires are correctly sized etc is it intrinsically any less safe? Apart from the lack of earthing currently in place, that is.

 

It seems as if it's the same as a regular CU that got exploded and scattered around the house 🙂 

 

It will certainly avoid any possible problems with shared neutrals though it could need a few more RCBOs and MCBs. Also careful segregation of wire before and after MCBs but nothing that's rocket science.

 

5 hours ago, Crossy said:

Those "safety breakers" are indeed MCBs and will trip at something like 120% of rated current. Do feed both L and N through them as they don't all have the over-current protection on both poles.

From my evisceration of my unit they also need the neutral for the neon lamp to tell you the current is actually on.

Edited by sometimewoodworker
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If all those exposed breakers had the plastic terminal covers fitted (they get "lost" as soon as the box is opened) or they were in the little plastic housings usually found on the shelf next to them in the store then it would be no less safe than using a consumer unit (actually more safe as you have 2-pole breakers).

 

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4 hours ago, ilikethai said:

I will definitely tell Spark to change the wires to proper size.  There are 1.5mm sq copper and a 2.5mm sq copper coming out from the shop meter.  It should be like only one double wire like a 16mm sq or bigger copper wire.

Did you add an extra number? 6mm copper from each meter will be more than enough.

 

5 hours ago, ilikethai said:

here is the stabilizer.  When everything is off the right display it's always at around close to 10.

So you are saying that it's showing a 10A draw with everything turned off? If so then you probably have pirates stealing power.

 

4 hours ago, ilikethai said:

20amp or 30amp main breaker for the 3/9 meter will be good size, right?

30A is a little high for an MCB. I wouldn't go over 25A

 

30 should be OK for a safe-T-cut, as it's the line neutral imbalance that's going to trip it, and the MCB that trips on sustained over current.

 

 

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13 minutes ago, Crossy said:

If all those exposed breakers had the plastic terminal covers fitted (they get "lost" as soon as the box is opened) or they were in the little plastic housings usually found on the shelf next to them in the store then it would be no less safe than using a consumer unit (actually more safe as you have 2-pole breakers).

 

Humm, when I bought the one I opened in the picture above there were no terminal covers in the box. Next time I'm in those places I will check to see if I can find anything.

 

Thanks, 

BTW do you have a picture of a surface mount RCB? I'm being lazy but I should probably be using one of those on my home made wire wheel and buffing station, so if you've got a picture I won't have to argue that they do actually have one. I can find DIN and Cu fitting ones, but so far not surface mount.

Edited by sometimewoodworker

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17 minutes ago, sometimewoodworker said:

BTW do you have a picture of a surface mount RCB?

 

Here you go, it even has the plastic terminal covers fitted 🙂

 

360 Baht or thereabouts plus 20-30 for the nice little box.

 

EDIT Important, you MUST get the Line and Load terminals the right way round, even if it means mounting the unit upside down.  If you swap line and load it works just fine, until you press the "Test" button at which point the magic-smoke comes out and it stops being an RCBO.

haco_breaker.jpg

 

Cover looks something like this.

0836d5772a2f49cde795af8cbf10f57a

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I put a cable meter after avr on both my 3500kw heaters and they draw 20 amps each with pump running when on full dial.

I have a 24,12 and 9 btu a/c's dual inverter and they all draw just under 4 amps each. 

Edited by farmerjo

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sorry late reply.  first of all thank you to all you your knowledgeable answers.  I'd been busing running around town with my friend buying stuff to get started.  We'd decided to change and put in main breaker and RCCO and change all wires.  What's weird here is that I just saw a store that sells 5/15 meters a Mitsubishi for about 1200 baht and a Chinese fake for 300 baht.  We were told just buy the meter and install it and the electricity worker will do the rest!  Yeah weird.  Anyway thank everybody so much and for everything and will keep you updated

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here is the stabilizer.  When everything is off the right display it's always at around close to 10.
20191018_051320.thumb.jpg.1c2534a2fa57cde389684862db406c19.jpg
I'm not saying that this is the problem, but I have 3 of the same types of stabalisers, and one of my stabaliser meters reads high (off the scale) but checking the output voltage everything is OK. Maybe they have sus. meter circuits?

Sent from my SM-J700F using Tapatalk

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