Supply cable and connectors dissipating 24W....how?

[treez]

Hello,
My boss tells me that he is supplying a 500W Switch Mode power supply from an upstream 48V SMPS. He says that he is getting 2V of drop in the connectors and supply cable from the 48V upstream SMPS. -Thus he is loosing 21W in the supply cable and connectors.......he won't let me look into it unless I can pinpoint what I want to look at straight away, but I reckon this is a connector crimping problem, ...giving too much loss in the connectors...do you agree?

 

[FoxyRick]

Wow, that sounds a real homework question, lol.

Connector crimping... maybe.
Oxidation of the contacts in the connectors... possibly. (especially if they are dissimilar metals.)
Sharp bend causing fracture in the connecting wire*... could be.
How long and what gauge is the connecting wire???


*I once saw a UK mains outlet with only a television plugged in start to smoke. On investigation, I found that the solid-core T&E cable had been bent sharply back on itself when the socket was fitted to the backbox. (not my work!)

The stress in the wire increased the resistance at that point enough to dissipate such heat that the insulation melted. Just from a TV's current! Admittedly it was a big, old rear-screen projection TV that probably ran at a few amps.

 

[andre_luis]

Losses amount at such level in my opinion would be more feasible to occur on cabling, but not at connections itself, due this would imply on a heat being dissipated at a small region, producing a quick heat rise, able to burn anything.

 

[KlausST]

Hi,

a 10 m cable (with 1.5 square mm copper each wire) has the same dissipation.

Klaus