Crimping mains flex

[Pandora]

On a central heating control circuit, I have a FCU with a mains flex outlet. I wish to connect a small pump to this FCU. The cable from the pump to the FCU is 0.75mm=B2 3183Y flexible mains cable.

When I connect the flex cores to the terminals on the reverse side of the FCU's front plate, the mechanical contact between the terminal screw and the stranded conductors feels a bit weak. If I terminate the end of each flex core with an insulated pin crimp, the mechanical connection seems much better.

My question: Is using insulated crimp terminals on mains flex within a wiring accessory permitted by the Wiring Regulations?

[ARWadsworth]

When I connect the flex cores to the terminals on the reverse side of the FCU's front plate, the mechanical contact between the terminal screw and the stranded conductors feels a bit weak. If I terminate the end of each flex core with an insulated pin crimp, the mechanical connection seems much better.

My question: Is using insulated crimp terminals on mains flex within a wiring accessory permitted by the Wiring Regulations?

I see no reason why not. I assume that you are using somthing like

I would strip twice the required length of insulation off the .75mm flexes and double over the exposed copper before shoving it into the screw terminals on the FCU. I know what you mean about .75 flex into FCUs. It looks weak and often gets caught in the terminal threads. Adam

[Roger Mills]

Why not twist the end of each flex core, and run some solder into it - so that you have a solid cylinder for the final 1/2" or so?

[Steve]

Because solder tinned connections will creep under pressure from the crimp/screw terminal and eventually leave a loose connection.

Steve

[The Medway Handyman]

I've often thought that, if connecting two or more cables into the same terminal it would be a neater job to crimp the cables together first, then tighten the terminal screws onto the pin?

Does a 2.5mm Pre-Insulated Crimp Pin Connector take more than one 2.5mm cable?

[Dave Liquorice]

No, solder creeps over time under the pressure from the screw and the connection becomes "loose" maybe not mechanically noticeable but electrically the impedance can rise leading to a burnt terminal.

A crimped bootlace ferrule is what should be used on the end of flex wires to manage the strands.

[ARWadsworth]

Afraid not. 2.5mm crimps are a perfect fit for one 2.5mm cable

Adam

[Andrew Mawson]

first, then

Very useful little things that save the problems of loose strands bridging adjacent terminals. I've used hundreds (perhaps thousands) in industrial control cabinets going into DIN rail terminals. Especially useful where you are pushing in wires in semi darkness in hard to reach areas. Only useful for one wire though.

Don't solder the end of a stripped wire for terminations - it makes the wire inflexible up to the end of the solder, and it will eventually break there if there is any movement or vibration.

AWEM

[Grumpy owd man]

Try getting hold of some 'bootlace ferrules' available from about

0.5mm^2 upto 25mm^2. The smaller sizes can be bought in a 'two wire' version,max is about 2 x 1.5mm^2. Mind you, you need the correct tool to crimp properly otherwise the pins start to deform. HTH

[Pandora]

cantilevered tool to fix it.