Panel Full, Now What?

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Thai4

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So, a little context; This project is on a residential property in rural Thailand, 240 Volt single phase if I am not mistaken. I am not an electrician but feel comfortable tackling the job with some guidance. Building code is irrelevant if it even exists and there is no inspection or enforcement. That's not to imply that i don't want to build something safe but no need to go over the top. Local electricians will not likely speak English and my Thai is **** poor.

This property has a breaker panel at the street supplying two residential structures; a main house and a small cabin. Each of these two structures have secondary (Secondary to the panel at the street) breaker panels made by Schneider with Schneider breakers, a 63 Amp main breaker and mostly 20 Amp individual circuit breakers. See photo attached.
20180329_100921.jpg


I want to add two more small cabins with single 20 Amp circuit service each. I had planned to pull this power from the breaker panel in the main house as the initial panel at the street is too far away. As mentioned, the breaker panel in the main house is full.

Searching the internet for a solution, I discovered tandem breakers. I have a few existing circuits on the main house circuit breaker panel that are very lightly used. I thought I could shift these to two side by side tandem breakers and open up two vacancies for single pole breakers to service the two new cabins. I contacted Schneider who does manufacture tandem breakers but they do not market them in Thailand. Unfortunately, it seems tandem breakers are not available in Thailand at all. I have considered that I could get them shipped from America but I don't know if they will be compatible and suspect they wouldn't.

So my next thought was to install a sub panel. I understand even for a sub panel, I will need a spare slot in the main house panel for a breaker to supply the sub panel. I assume I could move one of the existing circuits in the main house breaker panel to the sub panel and in doing so, create a vacancy but now we are getting more advanced. Having a look at the local equivalent of Home Depot, Global House, They don't seem to market sub panels either. They sell lots of breaker panels with a main and a series of individual circuit breakers but I am not sure if I can use these as a sub panel.

My next thought, I could simply upgrade to a larger main house breaker panel but mine has 14 individual circuits. The largest one sold at Global House has 14 individual circuits.

My latest thought, can I simply "T" off the main power leads supplying the main house and run a leg to a secondary breaker panel that would have a main breaker and at least two 20 Amp circuits to supply these independent cabins? Lets just assume there is adequate power available to begin with if we can.
 
Gentlemen,
Can anyone advise Thai4 if those Schneider Electric QOVS C20 20A MCBs are DIN standard breakers, as I suspect they are.

In any case, are "tandem" breakers available (from any source) which can be installed in place of one existing breaker in that "panel"/Consumer Unit?
 
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Your setup looks like it is some hybrid of US and Euro practices. The board looks European, both in it's layout and in the markings on the breakers but the wiring colours look closer to US practice. Maybe that is the norm in Thailand I dunno. I have no idea if you can still get breakers for that particular board or if new boards sold in Thailand today are closer to UK or to US practices (some quick googling seems to indicate Euro but I don't know how accurate that is).

There isn't really any difference in the panels themselves between a main panel and a sub panel. In the US there are differences in the grounding arrangements, I have no idea what the situation is in Thailand.

I have never heard of "tandem breakers" in Europe, they seem to be an american thing.

So my next thought was to install a sub panel. I understand even for a sub panel, I will need a spare slot in the main house panel for a breaker to supply the sub panel. I assume I could move one of the existing circuits in the main house breaker panel to the sub panel and in doing so, create a vacancy but now we are getting more advanced. Having a look at the local equivalent of Home Depot, Global House, They don't seem to market sub panels either. They sell lots of breaker panels with a main and a series of individual circuit breakers but I am not sure if I can use these as a sub panel.
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I see no reason why not, in most places the same panels are used for both.

In the US they bond Neutral to Earth in the main but keep them separate in subs. In the UK we always keep them separate in customer equipment (they are sometimes bonded/combined in supplier equipment), if in doubt keep them separate in your new panel.

My latest thought, can I simply "T" off the main power leads supplying the main house and run a leg to a secondary breaker panel that would have a main breaker and at least two 20 Amp circuits to supply these independent cabins? Lets just assume there is adequate power available to begin with if we can.
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If the cable has adequate over current protection at the source end (you describe it being fed from another panel so it probablly does) I don't see any problem with doing this.

Another thing I would consider is whether you really need so many separate circuits. Could some of the lighter used ones be combined on to the same breaker without causing them to be overloaded?
 
Thank you Plugwash for some good advice. It sounds like my options are not as limited as it seemed.

This panel is roughly five years old but I couldn't tell you if it's US or European. Presumably the breakers are not interchangeable?

plugwash said:
There isn't really any difference in the panels themselves between a main panel and a sub panel. In the US there are differences in the grounding arrangements, I have no idea what the situation is in Thailand.
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I thought a breaker panel designed to be a main panel was designed with a main breaker protecting the subsequent circuits. It looked to me like sub-panel was designed without a main breaker and dependent on a breaker in the main panel. If this is correct, it may be that it doesn't matter. Thats where my inexperience shines. From what you say, it sounds like I could use a main panel as a sub panel.

You may know tandem breakers by a different name: duplex, slimline, twin, half-height, half-inch, double and waferbreakers. Essentially two circuits fit into the footprint of a normal single pole breaker if I understand correctly. This seemed like the easiest solution to open up vacancies in the box for two additional circuits. It also seemed to fall within my abilities whereas a sub panel is pushing the limits.

plugwash said:
If the cable has adequate over current protection at the source end (you describe it being fed from another panel so it probablly does) I don't see any problem with doing this.
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In regards to simply "T'ing" off the main and building a second main, it's good to hear this is possible. This also sounds like a good solution for me. I could simply copy the wiring on the original panel.

plugwash said:
Another thing I would consider is whether you really need so many separate circuits. Could some of the lighter used ones be combined on to the same breaker without causing them to be overloaded?
Click to expand...

I agree, there does seem to be way too many circuits. Several of them have nothing more than a single florescent lamp on them. This may be the best solution to double up some of the lightly used circuits. I wasn't sure if I could just join two hot leads to the same breaker or not. It sounds like this is acceptable provided the combined load is less than the pre existing breaker rating.

Thanks so much for your advice.
 
Thai4 said:
I thought a breaker panel designed to be a main panel was designed with a main breaker protecting the subsequent circuits. It looked to me like sub-panel was designed without a main breaker and dependent on a breaker in the main panel.
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That may be the case in the US, i'm not 100% sure. Here in the UK panels normally have a main switch or sometimes a main RCD but very rarely a main overcurrent breaker. Overcurrent protection for the installation as a whole in the UK is supplied by the electriciy supplier.

Either way from a safety point of view having an extra breaker isn't a problem.

You may know tandem breakers by a different name: duplex, slimline, twin, half-height, half-inch, double and waferbreakers. Essentially two circuits fit into the footprint of a normal single pole breaker if I understand correctly.
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I have seen americans talk about such things online but I have never seen one to fit a European panel.
 
Don't get tandem breakers or anything else from the US as they will be designed for 120 volt systems.
 
winston1 said:
Don't get tandem breakers or anything else from the US as they will be designed for 120 volt systems.
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I agree with your comment on "Tandem" breakers but there are North American manufactures producing DIN/IEC 60898-1/IEC 60947-2 breakers with Voltage ratings which cover 230 V AC, both for their local market and for export.
(e. g. http://www.geindustrial.com/products/circuit-breakers/elfaplus-global-din-rail-devices-ul-approval)

Of course, Thai4 can obtain DIN/IEC 60898-1 MCBs and Customer Units to suit them form a large number of manufactures throughout the world and because they are made to that International Standard all MCBs of that design will fit all CUs designed for that standard.

However, it might be better if he purchased locally.
 
Talking of third world electrics I witnessed an electrician in Brazil hold a lightbulb in his mouth that had two wires soldered to it and use it a circuit tester.
 
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