Help Me Design My Circuit Distribution Panel

[BuddhistDruid]

The recent floods were 2.7 meters in my housing estate, and left my circuit distribution panel completely submerged for 2 months. I want to completely replace them. I attempted to get the only Thai electrician I trust to do the work, but unfortunately he has a queue of work approximately 3 months long. So I am left to do this myself.

First, I am from the US, so forgive my terminology if it differs from what is in common usage here. I would also feel much more comfortable doing this in the US where I have a much clearer understanding of how to proceed, but I don't think the basics can be substantially different.

I am also going to refrain from offering my opinion of what I should do to avoid causing confusion. I would like to present the problem, and then get a list of everything I will need to complete the task. I essentially have nothing right now except a screwdriver and multimeter. All of my tools were destroyed in the flood, so I will need to buy or borrow everything.

I would like to make a list and then make a single trip to Home Pro to purchase everything, as I am going to be left at my house without power and without a car for the day. I need to complete the install before the sun sets, so I need a good plan.

What I have is the following: 12 circuits in the house are already wired to a central location, but it will be necessary to trim the wires for the new panel. The newer circuits that were installed when we remodelled are grounded. The older ones are not. 2 of the circuits go to compressors with a large inductive load and therefore should not pass through the RCD. The other 10 are conventional domestic circuits that need to be protected. (I will additionally be replacing all the outlets that were submerged, but that need not be considered now.)

The circuit from the meter is rated for 100 Amp single phase. What I'd like is a main breaker at 100 Amp, with the 2 inductive loads fed from this on independent circuits. Then I would like to go through a Safety Cut, and finally from there feed the remaining 10 circuits. If it makes a difference assume all circuits are 15 amps.

I am asking for help upfront so I don't overlook something. I know these projects always have a way of becoming more involved than they seem at first, so I am attempting to go in prepared.

If you were me, what would you buy to complete this job? Does anyone make a split distribution panel for example, with one side protected and the other side not? (In the previous incarnation, a sub panel was used.) I very interested in any tips that those who have done this before might be willing to share on how to complete this with a minimum of fuss.

Thank you for any assistance.

[Crossy]

A few thoughts to get you going.

Electricity here is easier than the US as we have only a single supply, wire as you would your 115V and you won't go far wrong.

Have a look here http://www.crossy.co...g/Consumer.html , scroll down to the Split Service CU drawing. It's not rocket science You probably won't get a purpose designed split CU so you'll be taking a hacksaw to the neutral bar You will be able to get a DIN mount RCD to put in the same unit, so no external Safe-T-Cut.

Buy a CU with DIN rail mounting breakers, it will be easier to modify.

How are you arranging isolation of the supply whilst you work? I would not recommend working live! I would get yourself a 100A stand-alone breaker and install that first on the incoming supply and feed your new CU from it, if the worst comes to the worst you can wire a trailing outlet to the switched side and run a few lights etc. if you don't finish or hit unexpected snags (you will).

Since you've been flooded you should do an insulation test (with a proper insulation tester not your multimeter) on all the cables that have been wet, they will probably recover when they dry out but you'll save yourself headaches when the RCD won't set.

Get some butt crimps and a decent crimping tool so you can extend wires safely and quickly when they don't reach.

I would plan to get some lights going first, then outlets that didn't flood, take it gently and do it over several days rather than try and rush it all in to one, if you install a separate isolator like I suggest you'll be able to do it safely and a bit at a time.

[bankruatsteve]

I suggest you re-think your one day plan. If you were that flooded and if not done the insulation tests already, it seems likely that you will need to re-run one or more of the circuits. (?) So, then you will need extra cable, various sized screw connectors (or whatever). Have you tested your receptacles and switches with your ohm meter to make sure they still work? You may want to pick up some more of those. And sorry, just have to laugh when I recall the "one day" projects I have had and thinking only 1 trip to the "Home Pro" place. Aaagh.

[Crossy]

My edit went wrong

Try and get your tame sparks to install the isolator for you, he'll do it live so you dont' have to

[BuddhistDruid]

Thank you for all the help so far. I've found a Thai chang who is going to come over here and do the live stuff for me so I don't have to risk injury and death. I appreciate the appeal to good sense.

Another question though for those of you who have done this before.

Because I am not at all convinced that this will be the last time my house floods, and I am not prepared at this point to move the location of the consumer unit due to the difficulty involved, I want to build this without using any special components. Which basically means, if it isn't available at Home Pro, I don't want to include it in the design. That way, if and when the floods come again, I will be able to quickly source the required components and get back in business without undue delay.

So I am left with trying to understand how to actually add a secondary CU to the primary unit. In the states, the circuit breaker panel had a special connector for this which was trivial to wire into. On these cheap Square-D units, I can't find any way to jump the hot lead to the secondary CU after passing through the main breaker.

So I thought I would simply use a 60 amp circuit breaker off the primary CU, run that through the Safe-T-Cut and then into a 60 amp main breaker on the secondary. OK, this would be 2 circuit breakers for a single circuit, but at least it would work.

Unfortunately, I can't find a 60 amp circuit breaker anywhere for the primary CU. 60 amp main breakers are everywhere, but not a single slot 60 amp breaker for the primary.

So, I'm stumped. How do I actually get the hot wire off of the primary CU on the protected side of the main breaker?

Anyone ever done this before? Again, no specialty parts. Whatever the solution is it has to be very common so that after the next flood the Thai contractors can easily replace it.

Advice?

Edited March 6, 2012 by BuddhistDruid

[Crossy]

I'm sure I've seen single unit 63A Square-D breakers, 50A are definitely available and TBH will likely be more than adequate.

[bankruatsteve]

I put a blade switch (fused for 62a) isolator from the PEA ie: in front of the CU. Then, from out of that to 2 CU's.