Compliance in the DB

Hoping to find some answers here…

My DB was apparently installed when there was a massive copper shortage world wide because every wire is “just about long enough”.

Unfortunately to do a proper install of an inverter and have an “essentials circuit” I would need to change to a surface mount DB (2 rows) which means most of the wires in my DB will be too short.

My idea was to use these

in the DB to be able to extend (both neatly and not too difficult).

But… not sure if these are actually allowed in a DB (or any residential electrical installation) in SA.

Anyone know? or have a better idea of how to do this?


I don’t know if it is allowed or not.
But my only suggestion would be to move the surface mount box 5cm higher (closer to the wire assuming the wire is coming from the roof)

You do get these double box DBs where it is 2 units (1 above and 1 below) that might work as well.
I have a wooden house with drywalls so that is the easy option where I do know many other brick houses will require a bit of grinding that is not the easiest option.

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“old” house so plugs are wired from below, lights from above…

I went for a “tripple” and am very happy I did.

Have lots of space for all the bits with extra. Surface mount also means more space behind the board.

Ja it looks like I will need many lots of slots, there is a metal 2x18 that would work and the more common 3x12 plastic variety…

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Why not just crimp on an extension using a ferrule, and heatshrink it?

It is essential to use a good crimper. At least one of the ratchet style ones, not the hand ones you get for free at the hardware store whenever you buy a box of terminals… :slight_smile:

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you have to come here with your logic and common sense?


realistically I would need a crimper that can handle battery sized cables too… this is going to upset the bank manager something terrible.

I ripped out my plastic one and installed a bit larger metal DB. I just hate the plastic ones as the just bend and twist when those think wires are used so it is a mess. Only benefit of a plastic model is less chance of a short.

New wires perhaps?

I had the same issue when replacing my DB. I extended all the wires that were too short using ferrules and covered with good quality heatshrink. As plonkster said above, use a proper ratchet crimper, they not expensive for smaller than 6mm ferrules. When I did the DC stuff, I borrowed a big crimper from a friend.

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whole house rewire?!? maybe if it was all running in the roof… electricians who wired this house had a seriously sick sense of humor… keep the wires short AF, make sure you can’t fish a conduit afterwards because who knows where it splits off to (the roof by the front door is concrete… there’s some interesting thing going on with the conduits there. There was also some kind obsession with dimmers and 2-way switches. Oh and don’t forget the 12V recessed lighting…

The house also came with a CoC… the electrician must have been either blind or stupid… found an extension going into the roof space where it was cut off and joined to a kettle cord that was exiting the roof in another spot… wires were simply twisted together and wrapped in some R2.50 insulation tape. The aircon is plugged into a plug… yet the cable runs through the wall. The garage door motors… Well there’s a plug… one cable disappears into the roof and two power cables come out of the roof…

That is not necessarily wrong. Up to 12,000 BTU can legally sit on a plug.

House sale checks are easy money. Most home owners don’t know, and since the bill is often paid from the proceeds of the sale, they can charge silly money for doing very little.

Well, I don’t want to generalise. The guy who did my house before I sold was very thorough and I definitely got value for my money. If you are in the Western Cape Boland area, you can always call Mlilo Last, he does work for BorerBeatles (company name).

But the people who did my new house… well… the main DB board didn’t even have overload protection and nobody picked up on that. There was a cable hanging out of the drywall in my office, twisted to a light switch on the other side, and the laundry room still has a rats nest I need to fix one day. But somehow there was still over 12k worth of stuff that was apparently fixed…

  1. This one is 18000btu
  2. Nothing is allowed to plug in afaik if the wire goes through structure (wall/ceiling)

That’s interesting. Every A/C (of the smaller variety) I have ever seen has the wire going from a plug through a hole in the wall to reach the outside unit. Then there is an isolator right next to it (cause you must have that). I think you’re not supposed to use cheap cabtyre though… :slight_smile:

But I’m not an electrician. I’m just remarking that if this is what the regs say, then a split unit can never be on a plug, cause in a split unit there is always an AC cable going to the outside unit.

It’s a practice I’ve seen with garage door motors too… I don’t know if this requirement has changed over the years. I’m not an electrician either so I’m just going on how it was a looooong time ago. I guess the isolator next to the unit is the key there… not running cabtyre would mean that physically wiring it into the back of the plug would make it legal?!? (provided we’re not exceeding the limit of the breaker)

What I mean here is that often people will just use the thin 10A or 15A cable that you’d use for table lamps or extension cords, and they wire the AC with that. This cable is of course no good for outdoor use, and is generally referred to (by sparkies I know) as “cabtyre”. But you do get decent cable that is still soft enough to fit into a plugtop. As I understand it, it is okay as long as you use that cable, and put an isolator up outside.

But then again, I somehow remember (in the recesses of my mind) that you cannot put unarmoured cable through a wall, ie you need to use at least twin-and-earth or surfix, and that is too hard to properly go into the back of a plug.

What I have also done in the past (for network cabling mostly), is drill a 20mm hole in the wall and line it with a short piece of conduit. Then the cable is protected against damage in the (cavity of the) wall.

What I do know is when someone came to install my aircon (12k btu in bedroom), he said he can plug it into an outside plug I had close to the outside unit for the time being, but an electrician will have to come wire it in on its own circuit breaker on the DB.

So that is what I did. Never asked too many questions or read the regs.

At the previous house the sparky said the same. I had an outside plug that was used to drive a water pump. The 9000Btu unit that was right next to it was allowed to plug in there.

In the main bedroom I had a 12000Btu. It plugs into the wall, and the cable is in trunking on the outside, comes through a hole in the wall, and plugs in on the inside. All they said was the socket should be replaced with a model that has two sockets, so the AC van be on its own one permanently (instead of living on a multi-plug with some other stuff).

Sooo… this stuff is definitely applied differently by different people…

As for actual power use, even an 18000Btu does not use so much power that it cannot live on a plug. Especially if it is an inverter unit. But I have also seen a 9000Btu unit completely melt a socket, because the socket was very poor quality. It is this latter case that I suspect is the reason for the rules. Stuff that are permanently connected sitting in sockets… tends to suffer some neglect.

Indeed… Cheap hardware would be bad… As would incorrectly sized breakers. If the capacitor on the motor for the aircon goes you might well find that it draws enough current to ruin a cheap plug… The breaker on the plug circuit for that plug seems to be a 20A… So plenty room to destroy a plug that’s most likely rated for 16A…

Speaking of compliance. This weekend I again had to fix up a whole heap of crap.

It started with this little light switch, which is more like “De Aar” is for trains, it also serves as a junction box for the whole laundry room.

That “chocolate block” terminal block made arcing noises. Initially I didn’t have the time to make it neat, so I torqued down the screws and it worked in the interim. Finally ripped it out and crimped it with some heat shrink.

Then this weekend I tackled the outside, a light and a socket fed from that same “junction box”. What a mess…

The light is just left dangling loose in there. Also note… no earth connection.

Two red wires… why not…

And the socket is wired the wrong way round, which means the switch is in the neutral line… for the pump in the fish pond…

All of this passed a CoC of course. Now I do understand that when you do a CoC, you don’t necessarily check everything, you check a good subset. Some things will be missed. But in all the houses where I was on the selling end, the sparky pitched with an earth tested and tested every metal thing in the house… it is not a difficult test to do. You don’t even have to unscrew anything.

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