Crimps and connectors

[TheCat13]

Hi all,

Some advice if you would be so very kind.

1. I am looking at connecting some wires which will be concealed under floorboards and am aware that they should ideally be crimped. Now there are loads of different types, so what is recommended please. Also are there different types/ratings for different cable sizes/amps? Also what type of enclosure should be used.

2. If laying cable in a wall, is it acceptable to simply clip it as long as there is RCD protection on the consumer unit for that particular circuit

3. What is the recommended method of laying cable in a wall, i.e. conduit, sheathing etc...

Many thanks in anticipation of any help.

Sam

 

[davy_owen_88]

Insulated crimps are colour coded based on the cable size it should be used with:

RED: 1.5mm²
BLUE: 2.5mm²
YELLOW: 4-6mm²

Remember that the protectice conductor (earth) is smaller than the live conductors so in the case of 2.5mm² t&e you would use blue crimps on the phase and neutral conductors and a red crimp on the CPC (after sleeving it green&yellow of course... ) Regarding enclosures, you can either cover the whole joint in heatshrink sleeving or place the connections inside a choc-box. Also remember that to make a sound electrical connection you should use a high quality pair of ratchet crimpers, not those cheap pliers used for automotive electrics.

When clipping cables to the walls it is acceptable to leave them with no additional protection so long as the cable is RCD protected - fitting capping over the cables prior to plastering will help to prevent any damage caused by the plasterers trowel though, and can save you some hassle in the future should he damage one without realising.

Ideally, installing conduit is the best option as it allows you to replace the cable without hacking away at the wall, only issue is that the current carrying capacity is reduced so you may need to use a larger cablefor the same load. It is also a bit more complicated because when you have multiple cables in the same conduit you must ensure that the conduit is large enough and apply the appropriate correction factors. I'm not sure what you mean by sheathing unless you just mean clipped direct with the grey PVC sheath used on twin and earth cable?

Davy

 

[TheCat13]

Thanks Davy.

Further Q.

There seems to be loads of different types of terminals (spade/fork/push on etc.), what type is recommended.

Also what type of enclosure should they be placed in or is sheathing sufficient.

Thanks again

Sam

 

[davy_owen_88]

If you are connecting 2 cables together you want to use insulated butt crimps

Either cover the whole joint in heatshrink sleeving or put the connections inside a choc-box. What sheathing are we talking about here?

 

[TheCat13]

Thats the fellas! Thanks

By sheathing I mean pvc insulation.

Also, is this method ok for extending wires in a new CU installation, where the old wires aren't long enough to reach the new terminals?

What would you use to apply heat to the heatshrink tubing as well.

Sorry to be a pain, the advice you give is invaluable.

Sam

 

[davy_owen_88]

Thats the fellas! Thanks

By sheathing I mean pvc insulation.

Also, is this method ok for extending wires in a new CU installation, where the old wires aren't long enough to reach the new terminals?

What would you use to apply heat to the heatshrink tubing as well.

Sorry to be a pain, the advice you give is invaluable.

Sam

If you can replace the wires from the last connection then that is the best method when replacing a CU, but if that isn't possible then crimps are acceptable - if the connections are made within the consumer unit you don't really need to sleeve the connection, and you definately won't have space for 6 or more choc boxes

For heatshrink you can use a heatgun set on its lowest temperature from a fair distance, don't go nuts with it, the repeated heating/cooling cycle could cause problems and heatguns can get to a very high temperature which can cause melting etc.

 

[ban-all-sheds]

Also, is this method ok for extending wires in a new CU installation, where the old wires aren't long enough to reach the new terminals?

Yes, but not by you, not yet...

 

[TheCat13]

Also, is this method ok for extending wires in a new CU installation, where the old wires aren't long enough to reach the new terminals?

Yes, but not by you, not yet...

Who knows, I may be Part P Full Scope and just asking for advice? What do you think?

 

[RF Lighting]

I'd be very worried if you were approved for full scope works, but don't know about very basics like crimping

 

[ban-all-sheds]

I think that if you are you should ask for your money back.

 

[TheCat13]

Thanks guys, you are really being useful. The fact that I am seeking advice on things before I attempt anything should be a good point. I am always striving to learn and better myself.

No training or courses teach you everything, you should appreciate that. I assume you two were born electricians with an implant on everything you need to know and an upgrade for being mightier than thou.

I know my limits and seek advice all the time. Its hardly my fault that the course and qualifications I took did not furnish me with 100% of the knowledge base I require to be the 'complete' thing. Is it also my fault that you do not need any knowledge or skills on crimping to pass Part P Full scope. I am sure there are loads of things that Part P does not teach you or test you on, but real life throws them up and you have to deal with them.

= = = = = =
Anyway, thanks to Davy for his help and co-operation.

Sam

 

[Softus]

Its hardly my fault that the course and qualifications I took did not furnish me with 100% of the knowledge base I require to be the 'complete' thing.

Isn't it?

Whose fault do you think it is then?

Is it also my fault that you do not need any knowledge or skills on crimping to pass Part P Full scope. I am sure there are loads of things that Part P does not teach you or test you on, but real life throws them up and you have to deal with them.

That's a fair point.

The best thing you could is do is buy a selection of crimps and practise with them. I haven't seen anyone mention a calibrated ratchet crimping tool, but this is a very important part of the process.

 

[davy_owen_88]

I haven't seen anyone mention a calibrated ratchet crimping tool, but this is a very important part of the process.

I mentioned it in the first post

 

[Softus]

I haven't seen anyone mention a calibrated ratchet crimping tool...

I mentioned it in the first post

Quite right - I apologise.

 

[Chri5]

Grow up.

You both have good and bad qualities, then again don't we all.

Airing a spate comes across as a bit silly and there really isn't any need for play ground antics on a very good web forum / resource.

Why not keep to that old adage "If you haven't got anything nice to say, then maybe it's best to say nothing".

Have a good weekend and chill