Running a Spur for a FCU

[FERMAC]

Is it ok to run a spur from an existing single socket and put a 3 amp FCU at the end for the pump for my shower (its not in the bathroom)?

Am I right in saying I have to use 2.5mm cable for the spur?

Also if it is ok to do this, if I wanted to change this single socket in the future to a double socket will it still be safe to keep the spur on it or would it overload it?

Thanks in advance!

 

[Spark123]

It is OK providing the socket is on the ring main and not already a spur (assuming you have a ring main?). You can replace the single socket with a double. 2.5mm is ok to spur from a ring main. Does the pump require RCD protection? Is there an RCD on the ring main or install a RCD Fused Spur Unit. If the pump is in a bathroom the circuit should be supp. bonded. Installing the pump in a bathroom is also notifiable under part p.

 

[FERMAC]

Not sure what type of circuit I have got, will try and check tonight. I can still add a spur to it if it is a radial circuit though can't I?? None of this is in the bathroom it is all in the airing cuboard and the bedroom!

The instruction manual for the pump says "the pump must connected to a 230V a.c. supply and must be fused at 3 amps via a double pole isolator, with a contact seperation of at least 3mm, it is also recommended that your installation is protected by a RCD with a trip rating of no more than 30mA"

There are no RCD's currently on the circuit (I have the old style consumer units) so I was thinking of using something like this http://www.screwfix.com/app/sfd/cat/pro.jsp?id=83049&ts=28415

Would it be ok to wire this on to the end of the spur and then wire the shower pump into it? Its says its 13A but I can change this down to the required 3A by just changing the fuse, yes?

How do I find out if the contact seperation is at least 3mm??? or is this a standard in all FCU's in the UK?

This is probably a stupid question bit this RCD instruction manual says it is 240V rated, but the shower pump manual says it needs to be connected to a 230V a.c. supply, does this matter??

 

[Qedelec]

You can add to the end of a radial as long as it does not adversely affect the original circuit.
240 was the nominal voltage until the generating companies decided to lower the figure to 230, but mostly you will measure 238v.

Make sure you assess the installation before attempting this work and it is mandatory that you upgrade earthing and bonding arrangements to the current regulations.

 

[FERMAC]

Ok thanks, sounds like its getting out of my depth, I need to get an electrician in to put the new downlights in the bathroom anyway so I think I will get him to install the shower pump and check bonding at the same time!!

Is this likely to cost be hundreds of pounds, to install 5 50w downlights (lighting connection is there from previous light), checking earth bonding on new shower pipework and running a spur a few metres to install a new shower pump?

 

[Qedelec]

Good man! It takes a big man to see limitations.
Cost is relative to job and its difficult to see from here, but consider that the cost is likely to be approx 25/hour plus parts.