Identifying crimped connectors

[DeadJoe]

How do you tell the difference between ring and spade-type connectors suitable for 240V, and those suitable for 12V? They seem to come in the same colours - red, blue, yellow, which reflect the wire size. Surely they are not the same?

Or are they? How would I know if someone has used the correct sort?

 

[wingcoax]

What are you using crimp connectors for on 240v ?

 

[dcwuk]

These crimp connectors (butt stylee) have primarily been used in the automotive industry. Three sizes are available for cable conductor size of 0.5-1.5mm2 (Red), 1.5-2.5mm2 (Blue) and 3.0-6.0mm2 (Yellow). Sometimes the stranded measurement is given, but I won't bore you with them...

Amperage specs for AUTOMOTIVE cable:

1mm2 8.75-16.5A {Depends on how many
2mm2 17.5-25A {and what size strands
2.5mm2 21.75A
3.0mm2 27.5A
6.0mm2 42A

The voltage is not relevent to the current rating of the crimp however the thickness of the insulated part of the crimp is.

Any use to ya?

 

[bernardgreen]

The voltage is not relevent to the current rating of the crimp however the thickness of the insulated part of the crimp is.

Since the ring is terminated onto a bare stud terminal the safety from touch insulation for the connection has to be provided by something other than the "insulation" on the crimp. The "insulation" can also serve to ensure the metal folds correctly when crimped.

 

[wingcoax]

Most of these crimp tags are used on panel wiring with a voltage of around 110vdc with some at 240v. All are normally terminated in special terminal blocks (not chocblock) which give a degree of contact touch safety. Any with 240v are then extra protected with perspex covers. This said, access to these connections is usually restricted by interlock systems and/or padlocks withe the keys in secure keeping.

 

[DeadJoe]

I just knew this would get complicated...

What are you using crimp connectors for on 240v ?

Bit of background:

I have a 300L thermal store fed by a solar panel coil, wood burner and two immersions - a low one on a timer, for heating up the entire store overnight on E7, and a high one on a timed button, which was originally meant for an hour of day time topping up, if the store heat were to get exhausted. The store runs radiators and hot water.

Anyway, during the summer, when the radiators are not used, it makes little sense heating up the whole store with the lower immersion, so a method of switching to the high immersion is needed, to ensure that just the upper part of the store is heated overnight, leaving the lower part cool, so it can make the best use of solar as a pre-heat for the next day, and saving a few units of electricity.

The sensible solution is a relay with a switch, so I can switch the power going to the lower immersion to the upper one through the summer.

The crimps are for connecting the relay to the immersion cables, inside a surface mounted junction box. I had something supplied for the job, pre-wired, a couple of years ago, but it was never installed, and now I'm looking at it, and I am anxious that the supplier has used rubber cable and not PVC heat resistant cable. And actually, now I look at it again, the connectors used are actually colour coded - there's red and blue connectors (which do not correspond to live and neutral - the red connectors have been used on the switch connections, and blue on all the immersion circuits). I'm also not convinced by the solution used to hold the cables in the box - it doesn't look that secure, to me. And, as if that wasn't enough complication, I can see a much tidier way of doing the job than the one that was suggested originally...

I don't especially want to tackle it myself, but I do want to fully understand what is right and what is wrong...

Is it OK for me to talk this through in a bit more detail?

Wiring diagram drawn by small child...

http://f.imagehost.org/0484/wiring.jpg

 

[mattylad]

Lots of stuff uses crimp connectors for 240v, try looking inside any microwave, washing machine etc.
Makes for a realy quick assembly.

I'm not sure that there is actually any difference between 12v/240v versions.
240v one will obviously be completely insulated (covered) so you cannot touch the exposed metal bits.
(Except for ring's, but they are usually only used on earth terminals etc)(or extra low voltage high current connections).

 

[wingcoax]

The difference is that the 240v types are usually beefier in the connector size,especially the "lip" types.

 

[ColJack]

The difference is that the 240v types are usually beefier in the connector size,especially the "lip" types.

what coblers..

please give proof..

 

[ban-all-sheds]

I am anxious that the supplier has used rubber cable and not PVC heat resistant cable.

PVC isn't heat resistant.

Rubber can easily be.

 

[DeadJoe]

PVC isn't heat resistant.

Rubber can easily be.

This was a surprisingly useful answer. I have both sorts of cable, and both have 'heat resistance to 85C' printed on them. I came to the conclusion (erroneously?) that the rubber cable was more likely to be problematic in future. The store regularly gets up to 80C (it's designed for 95C), and is currently wired using PVC with copper cores. The 'new' wiring is rubber, with a white metal core (steel?).

If this cable is OK for modern applications, then my confidence in the rest of it increases somewhat...

 

[ban-all-sheds]

This was a surprisingly useful answer.

I'm never surprised at the usefulness of my answers...

 

[DeadJoe]

I'm sure...

But your answer helped me establish that I am asking the wrong question.

In my mind, I had already decided the cable supplied was wrong, which in turn led to me questioning the rest of it, including the crimped connectors. I think I might have been a bit hasty - rubber cable is bad if it is red and black, 50 years old, and sitting inside your loft. But that doesn't mean it is bad if it is new and correctly rated for the job...

 

[wingcoax]

That is what i have found over the years during which i have fitted several thousand on sites belonging to HMG. Can't tell you where, (I'd have to kill you)

 

[dcwuk]

The voltage is not relevent to the current rating of the crimp however the thickness of the insulated part of the crimp is.

Since the ring is terminated onto a bare stud terminal the safety from touch insulation for the connection has to be provided by something other than the "insulation" on the crimp. The "insulation" can also serve to ensure the metal folds correctly when crimped.

Obviously