Re: [volt-nuts] Best way to measure micro Ohms

Hi, just my $0.02 worth. I have some instrumentation amplifiers here also looked into low resistance connections for my other projects. If I recall correctly you need to look at the electrochemical series. For interconnects on Al you want a metal similar on the ES. The oxide is a problem but if

Re: [volt-nuts] Best way to measure micro Ohms

I once repaired a Valhalla 2555A Current Calibrator (good for up to 100A output). It uses aluminum bus bars inside to route the current. The junctions between the bars had become higher than normal impedance and it could no long

Re: [volt-nuts] Best way to measure micro Ohms

An aluminum electrical connection needs a few things to be reliable: 1) a "springy" fastener 2) mechanical precleaning 3) an oxygen blocking coating. In the US, aluminum conductors are allowed for certain usages. We used to allow 14 and 12AWG receptacle wiring, but too many houses burned down.

Re: [volt-nuts] Best way to measure micro Ohms

Aluminum... Even with everything done right, with approved hardware, aluminum wiring will tend to 'creep' (Aluminum mushing out of the way of the lug screw or clamp. Just recently I checked the main lugs on my 150A garage sub panel, and sure enough the neutral lug was loose. This was about 8

Re: [volt-nuts] Best way to measure micro Ohms

I guess I would have to ask, "How do you know everything was done 'right'?" The evidence you have stated makes a pretty good case that it wasn't. The neutral entering a sub panel at most has the same current going through it as one of the line input leads, though in a 240V sub panel, load balanci