Very little. Changing the connector for a larger size, suitable for both the current rating of the circuit and the cable that is to be fitted to it, is the best way forward.

Unless catastrophic thermal self-disassembly is a design intent, of course.

Either change the wire gauge or change the connector. Those are your choices.

Ask a silly question, get a silly answer.

Being a hazardous area application I am pretty sure you can't just remove conductor strands to get the larger conductors to fit the smaller pins. Either way a 16AWG contact is miles smaller than a 2.5mm2 conductor so this just isn't practical.

Either increase the size of the connector pins (by ordering the right sized connector) or decrease the size of the conductors (if you can).

One thing I forgot to tell you that the conductor is singlre stranded. I measure the well diameter to be 1.7 mm and conductor dia to be 1.7 mm.

1. Is it okay if we grind the conductor a little bit.

2. Also the Amphe-Ex series from amphenol doesn't have any insert with 4 pins of 12 contact size.

3. Can anybody comment if I can insert 12 size contact into an insert meant for size 16.

Do you want it to work or do you want it to catch fire?

Why not contact your Amphenol representative?

So to paraphrase: you wish to pack 3 kg of manure into a 2 kg bag...

And you can't quite figure out how to do it.

Why the resistance to do as Anonymous Hero and the others have advised? Get some 3 kg bags.

One thing I forgot to tell you that the conductor is singlre stranded. I measure the well diameter to be 1.7 mm and conductor dia to be 1.7 mm.

No you cannot do this, I am not even sure if your standards allow single core conductors to be used (you better check your local electrical and hazardous area standards).

3. Can anybody comment if I can insert 12 size contact into an insert meant for size 16.

Again. I don't think you can for the Amphenol brand as they are sold as matching sets (at least the ones I used were).

If you cannot get the right size connectors and/or conductor you may be able to adapt them to the application by terminating multi-stranded 16 AWG wire to the Amphenol connector pins and running the conductors back to a set of terminals to connect them to the 2.5mm2 solid conductors. But again you will need to check with your local electrical and hazardous area standards to see if this solution is allowed for your particular application.

_{Jack - A hazardous area equipment inspector.}