Crimp terminals: current rating is rarely specified?

[Jodes]

I have looked for current rating for crimp terminals. I've checked some 5-10 suppliers, none of them say what the current rating for any of their terminals are.

I'm guessing they're meant to be able to handle the capacity of the maximum size cables that can fit into them? I'd prefer to know without guessing!!

Also would there be a difference between 230v AC current rating and 12v DC?

Pages such as this one tend to give conflicting values, e.g. I've seen figures 16A and 19A for red terminals.

Thanks

 

[Darkwood]

The general consensus here would be if it fits a certain sized cable then it will be rated for it, otherwise you need to contact the manufacturers.

The biggest drawback is the quality of your crimp - you buy and use a cheap crimping tool then your crimp may not handle the designed current, you best using a calibrated ratchet crimp.

 

[Lucien Nunes]

And the manufacturers will probably specify one particular tool or die set, without which the rating is not guaranteed, as the exact shape of the die nest varies from one brand of tool to another. There are also some cheap nasty terminals on the market that I wouldn't trust with half an amp, even if the cable stays in. You wouldn't buy an electrical fitting from an unknown manufacturer without a BS number on it, look for the approvals on any terminals you buy too.

 

[Marvo]

......Also would there be a difference between 230v AC current rating and 12v DC?

The voltage rating of devices is determined by the efficiency and ability of their insulation or the separation of individual components within the item.

Put simply, current rating is about the physical quantity of electrons that can be flowing through something without causing excessive heat to be produced. Current is a measure of the number of electrons flowing per second regardless of the voltage causing it to flow so if something is rated at 10Amps then it will still only be capable of 10 Amps flowing even if the voltage is lower. So in layman's terms a 10Amp fuse with a 230v rating will perform equally well if it's used on a 12 volt circuit.

With regard to your original question you can't take the size of wire that a terminal can be crimped onto as an indication of the amount of current it can handle. For example a yellow 6.3mm push on blade terminal can accept a 6mm wire but it's only rated to 20 or 25A (depending on manufacturer) because the blade is the limiting factor. You can't automatically rate it at 32A because it accepts a 6mm wire.

 

[Jodes]

Marvo - thanks for clarifying. Well spotted with the ratings of terminals vs. cable aperture. But regarding fuses, or mechanical contacts (e.g. relays), I am not convinced that it is always right to assume a lower voltage would be OK. Firstly there's the difference between DC and AC ratings, since AC can give a greater opportunity for an arc to be extinguished twice each cycle. Also, I can't remember the term, but for relays for instance, a higher (is it current, or voltage?) being switched prolong the life of the contacts? I didn't think it applied to connectors that aren't hot-plugged, but I thought I'd check anyway.

 

[Marvo]

Firstly there's the difference between DC and AC ratings, since AC can give a greater opportunity for an arc to be extinguished twice each cycle.

The rating of the current that can be carried by a contact and the current that can be disconnected by a contact are two different things entirely.

 

[Engineer54]

Think this thread needs to go into the DIY forum now!!