Fused connection unit mounted on metal backbox

[Spoon]

Yup, I’ve made a section of the floorboards liftable where the junction box is located nice and easy to get to

As already mentioned above. I personally wouldn't class a junction box under the floor boards as "accessible"

 

[Gary Tollison]

It is accessible. Lift back a corner of the carpet, remove a few small precut sections of floorboards...can get to
It in less than 30 seconds.
As long as there is access to it, I don’t see the problem

 

[pirate]

There's always access...just depends on whether the next person knows where to gain that access, and how. Ah...log-books for circuits! Another debate...
If you could run the spur to the FCU and straight out again in a straight line, would that worry you?
I ask this, as a non-spark, but am thinking if we ignore the eddy current debate (Please, let's ignore that here) then the leccy will turn the corner fine! and won't care what hole it comes in and exits from...
which is also another debate we probably don't need to pursue here!

 

[Gary Tollison]

I guess it’s down to the individual’s preference
As long as I can get to it with little effort then it’s fine.
But yes, there is the need of future notification of the “how to get to it” which must be addressed.
In an ideal world there’d be a detailed map of each electrical installation, but dreams are free

 

[SparkyChick]

I guess it’s down to the individual’s preference
As long as I can get to it with little effort then it’s fine.
But yes, there is the need of future notification of the “how to get to it” which must be addressed.
In an ideal world there’d be a detailed map of each electrical installation, but dreams are free

The reason you have a choice is because of ambiguity in the regulations regarding the word 'accessible'. My personal view is if I'm not going to be able to see it when the work is completed, it's not accessible and hence it should be maintenance free. Some examples... in the kick space of kitchen cabinets, under insulation in lofts, in walls and floor/ceiling voids. In some of those cases, it can be argued that they are easily accessible... sure, they are. But to access them you need to know something is there that requires it.

Looking at your profile, you're training to be an electrician right? Well, don't take this the wrong way, but in my view what you're proposing is a bad practice... secreting a junction box that will require inspection in the future out of sight within the fabric of the building.

Doing the job properly in the first place drastically reduces the possibility of it causing issues in the future and helps make life easier for the next person to work on the installation... an approach you'll appreciate when at some point that next person is you.

With regards to there being a detailed map, that's down to the person doing the work. I try and provide such information in the form of 'as installed' plans or notes on the certificates. After that, it's down to customer keeping that information together.

 

[Gary Tollison]

Ashley J803 Maintenance Free Junction Box 32A 3 Terminal - https://www.tlc-direct.co.uk/Products/ASJ803.html

Probably going to go with one of these for underfloor.
Even though access is easy, according to the regs, it “isn’t”.
So better safe than sorry!
Thank you all for the replies!
Opened my eyes a bit I must say

 

[Gary Tollison]

Heidi hi
Ok, so I’ve bought the maintenance free junction box (rather nice bit of kit too).
I’ve had a look at BS7671 app 15 regarding rings and radials.
After inspection and identifying the cables underfloor, I have this scenario:

An existing spur has been taken from a double socket outlet on the RFC.
The spur feeds a single socket downstairs in the lounge, which only ever has a 40 lamp plugged in, and the occasional phone charger.

In regard to RFCs and spurs, as far as I can tell, would it be acceptable to remove the existing spur from the socket outlet, and replace it with a cable feeding in to a switched fused connection unit, and from the FCU feed into the maintenance free junction box.
From the junction box would be both the feed to the shed (which would only have a light, occasional vacuum cleaner and power drill used), and the cable feeding down to the socket in the lounge?

Taking diversity into account, the demand from both would be low, even at the best of times.

Thanks in advance
Gary

 

[telectrix]

i would reconsider the shed feed. future use may require more power than you enviage at the moment. best way is a SWA from CU on it's own breaker/RCBO.

 

[Toneyz]

I try to avoid junction boxes in these situations as much as possible.
Does this RFC supply upstairs and downstairs, if so I would try to take from a socket directly.