Hi all
A quick one, I’ll have to upgrade some electrical stuff in a flat which was wired years ago, so might as well get things closer to spec to eventually get a CoC as well.
These days it’s a requirement to have a breaker within arms reach of a geyser, I read somewhere if you put a double pole breaker at the geyser then you can put a single pole in the DB or vice versa, is this true?
I want to put a CBI Astute in the DB for the geyser.
Then another one, yes I know it’s a how long is a piece of string question. I’ll be replacing the DB with a new bigger surface mount DIN rail over the old DB. How much empty space will you leave for future expantion?
So far if I count all current breakers plus the CBI Astute’s for the geyser and 2 aircons I want to add, oh and a ET112 meter, then I need a 20 way so far.
A geyser is a fixed appliance, so you require a disconnecting device within 1.5m from the appliance (6.16.1.4).
This disconnecting device must break both live and neutral (6.16.1.2). A double pole switch in a 4x4 or 2x4 box next to the geyser is commonly used. This is normally fed from a single pole breaker in the DB board. (A double pole breaker is also fine, but not required.)
The breaker in the DB must be of an appropriate rating in order to protect the cable.
You can have multiple geysers on the same breaker, but if you have a geyser on a breaker you cannot have any other type of appliance on it as well (6.16.2.2).
Geysers must be protected by an earth leakage device (6.16.2.1).
I suppose the only restriction would be that the wiring has to be able to carry the peak load when both appliances are active simultaneously, but as long as the wire is sized for it and you have a breaker to protect that wiring, you can have more than one.
I seem to recall, from years ago, that people would sometimes run an air conditioner from the same breaker as the geyser, because there may be enough room on the breaker, and that means they don’t have to fit a new breaker in a (probably full) DB. While it is a neat little workaround, it is of course illegal
Saturday morning out of nowhere, around 15 minutes after my Geyserwise switched on, while still in bed, I heard a pop. Upon investigation the Geyserwise screen was dead and the geyser breaker in the DB was tripped.
Investigated a bit further and it turned out the 30A isolator switch next to the geyser burned, that lovely burned electric smell which clings to your hands for days.
One of those things which will bother me for weeks to come, similar to a fuse randomly blowing, because there must be a reason “mos”?
My sparkie friend checked everything over and temporarily replaced the burned switch with a 20A breaker which I had on hand, I’ll buy a nice 2P replacement switch later today.
If you dig a bit, then any fixed appliances that may have a socket on them (eg I’ve seen some table saws that have a socket on them for powering other tools) must also have an RCD… but that falls under sockets above
It depends on what you want to achieve. If you want to be compliant with the current regulations, then @plonkster gave the correct answer. If safety is your primary concern then the answer is “nothing”.
For a new build, that is pretty much what I’d say as well. Just give everything RCD protection. Preferably split the install into two or three zones each with their own RCD.
For an existing build, where you’re considering retrofitting RCDs onto things, then you’d probably start with all sockets. And these days it is recommended to have the water heater on its own RCD, although in many houses it simply shares the big 63A RCD for the whole house… which is also alright.
My experience of industrial installations is that RCD devices are not fitted. This is due to the downtime caused by nuisance trips.
PS: In keeping with this philosophy my workshop/garage supply isn’t fitted with this
I’ve seen the mention of circuits not required to be on RCD like a stove if it is connected with the those old type of round connectors if I recall correctly. It does not make sense that anything you are likely to touch need not be on RCD. I have everything on two RCDs. One for loads before and one for loads after the inverters. Still wondering if the inverter input should be on RCD or not.
I have a DP breaker into an Astute in my DB and then into a DP isolator switch at geyser.
Regarding the 20way DB. I have a 3x 20way DB and I am more than 2/3 full for a 3 bed house. Bigger is better if it fits in the space. I should have drilled extra conduits into DB as you can never have enough entries into the DB.
@plonkster , now, I am confused, when you say “Geyser is not”, are you saying that the geyser does not require a RCD, although 6.16.2.1 says it should or are my interpretation of RCD and earth leakage messed up
I’m saying a geyser must be on an RCD. Doesn’t have to be on its own dedicated RCD (although this is recommended, see the note below), but it must have RCD protection.
Stoves are not required, in the current regulations, to have RCD protection. I’d still insist on it.
The geyser being on an RCD is a new thing. Most installations prior to 2020? the geyser will not be on an RCD. If you installed solar or made any change and needed a new COC after the change, it had to be updated so that the geyser is on an RCD to remain compliant.
Having plugs in your house or garage that is not on an RCD is very unwise and means that your installation is not compliant. If anything happens - your house burns down or somebody gets injured, you will most likely be liable.
