DANGER OF THE WEEK AWARD
Bad – New Home Builder
The home that produced last weeks winning award had another dangerous situation that has won this weeks award too. We arrived on Friday morning to sort out the issues around last weeks winner, the kitchen extractor to nowhere (more on that repair near the end) and while attempting to change a like-for-like cooker found another problem. This time it was poor thought out electrics hidden behind the cooker. At first glance and on the surface there doesn’t appear to be anything wrong. But when we isolated the cooker circuit via the cooker switch both sockets dropped off. Do you see the problem yet?
The problem here is that there are two distinct sockets. For them both to be switched from the single cooker isolator meant that they had to have been connected together. As the cooker circuit is already a spur (a single cable from the consumer unit) then this also means that one of the sockets is feeding the other hence a spur connected to another spur. A BIG no-no unless installed in a certain fashion. So with the knowledge that both circuits were controlled by a single switch it was time to check and make sure that the breaker had been adjusted to suit the situation. In other words the breaker would probably have been a 32AMP breaker to supply the current required for a double oven but should have been downgraded to 20AMP to supply the multiple sockets. Keep in mind that there is already one socket attached to the cooker isolator hence we are supplying three sockets here. As suspected the breaker was never changed and was 32AMP as required for an electric cooker.
The original cooker connector was removed at some point and replaced with a 13amp single socket which then fed another single socket just below. The top socket is fed from the original 6mm T&E feed as most often used to feed an electric oven. The spur to the second socket was connected with a short piece of 2.5mm T&E. Although in this instance the setup is unlikely to cause an issue it is not a safe connection nor is it allowed under the building regulations (BS7671). Even though the plugs themselves are fused at 3amp on the top and 13amp on the bottom. The fuse is to protect the cable, not the cable protect the fuse – cable must be sized accordingly or the circuit can be fused down.
It means that the cooker was plugged into the spur-off-spur sockets which was fed from the single fed spur above it which in turn was fed from the cooker isolator which also contained a single socket. As the 6mm cable on a 32amp breaker could take a fare amount of current the problem comes in if there is a short in the cable behind the cooker. It is worth noting that the location of the plug we are talking about is directly behind the fan located on the old cooker. So very hot air is already heating up the cable to start with. The 2.5mm cable will not take the high load that the 6mm cable with and the circuit breaker which is TOO large for this type of circuit will not blow quick enough. The outcome could be anything from the plastic melting off the cables to a fire starting behind the wall. As with all of these cases you just never know what could happen when things start getting hot enough to melt. I’ve also seen a lot of walls that have been stuffed with newsprint to plug holes before plastering up a big hole in the wall. Hot cables and newsprint in a hollow wall. Lovely! We are heading back next week to correct the electrics, install the new cooker and hob and finish off the extractor from last week. Se update below.
As for the extractor repair as mentioned above, it had to be postponed. As reported last week the builder had cut a hole in the outside wall but not extended the hole to the inside wall. We were wrong. Unfortunately however we weren’t completely wrong. The builder had actual cut a hole on the inside of the building but it happened to be about four inches below the outside hole. His solution was to ignore it and leave the extracted kitchen air to be expelled into the buildings air space3 between the inside and outside wall. We will be repairing that next week when the rain stops long enough to replace a few bricks on the outside wall at which time we will core a new hols low enough to line up with the inside cut.