Cannot have a Spur off a spur but can use an extension lead?

[Brian Matthews]

Probably a stupid question but why is it that you cannot (I think) run a spur off a spur but can connect an extension lead with loads of sockets on it? My son needs about six sockets in a new kitchen where there is only one double socket at present. How can it be done? As a matter of interest, we are trying to get an electrician in the Whitehaven, Cumbria area with no success. Are they all too busy?

Thanks

Brian

 

[pc1966]

When I get a new CU, would it be good enough to get one populated with RCD's instead of RCBO's? That would cut the cost a lot. Thinking about Schneider or Wylex ones. Any advice would be greatly appreciated instead of me diving in and buying a totally inadequate one.

Better to go with RCBOs, especially as you only have 6 circuits and might only need another one or two later, so cost difference to a dual-RCD board is small.

Schneider and Hager are the top ones, but rare in domestic settings and far more common in industrial sites.

Wylex and Crabtree are "traditional" brands and fine, they have double-pole switching RCBOs that make circuit testing simpler (used Wylex for my own flat).

Current favourite around these parts for the budget end is Fusebox, similar compact RCBOs to Wylex/Crabtree and very reasonable prices. Realistically a CU change cost is dominated by the labour (of course depending on any faults found that need fixing to make the system compliant and RCD-tolerant, such as "borrowed neutrals") so spending an extra £100 or so for less trouble down the road is a very good idea.

RCD/RCBO by their nature are prone to the occasional trip and with RCBO you only lose one circuit, not a bunch off the same RCD. Should there be a fault later then it is also contained to the one circuit that is impacted by it, making finding it quicker and cheaper.

 

[pc1966]

Checked the skt last night and it has only two cables in it. So presumably it is not a spur?

You mean two twin&earth cables, not two conductors (red & black, or brown & blue)?

As mentioned above, before modifying something you really have to find out what it is and how it is connected to the rest! Get a half-decent socket tested such as this:

TIS Socket Tester With Loop & RCD Check

A pocket sized checker for indicating loop impedance, socket polarity and RCD 30mA are all ok. Indication is by LED's and buzzer. An ideal unit for initial "checking out" of a 13A socket and will advise if the circuit is ok, needs attention, or needs urgent attention. An ideal product for...

www.toolstation.com

And you can see what goes on/off with difference MCBs. It might not be what you thought!

NOTE: Don't press the RCD test button for any length of time on that as you have no RCD and will just cook the resistor that causes the test current to be diverted (normally the RCD would trip off in tens of milliseocnds so resistor safe).

 

[timhoward]

I second the Fusebox suggestion - very good quality for the price.
I think the dual RCD vs RCBO question has been well answered - when everything is properly working as intended a dual RCD board is adequate.
When everything isn't working things rapidly become quite tricky especially with Neutral to Earth faults.
( Thomas Nagy recently made a video discussing this.

)

 

[brianmoooore]

It's DP MCBs that are missing in the UK, which would isolate earth neutral faults on split boards, enabling the RCD to be reset and keep the majority of circuits working

 

[timhoward]

Apologies @brianmoooore , I didn't check the previous page....