anderson plug voltage loss.

G'Day Diamond,

Have you checked the anderson power company web site to ensure you have the plugs assembled correctly?

I thought mine were O.K. until I checked the graphic on the site, all good now.

Rolande

You didn't say if there was any current flowing when you made that measurement.

If there was zero current flow then there is a problem either with the plug (unlikely because I would expect all voltage or no voltage at zero I) or with your measurement.

If there was (say) 10 amps flowing then as R = V/I: R = 0.9/10 = 0.09R or 90 milliohms and as that current has to flow through 2 pins (power and ground) then each pin is presenting a resistance of 45 milliohms which (from memory) sounds reasonable for a push fit connector to me.

Mike Harding

Hi Diamond - there are several possible reasons for a voltage drop.
The 2 most likely are - 1. gauge of wire and 2. assembly of anderson plug.

1. All wire has resistance when carrying a current, and hence a voltage drop.
My wire is 6mm diam of copper = 28mm2 area. Yes fairly thick (battery cable).
This has a resitance of 2.68mv per Amp per meter. So over a 8m length (from car to camper), carrying 20 amps, I would expect a drop of 430 mv or .43 volt.
The thinner your wire the greater the voltage drop, for a given current.
If you intend to charge the camper battery, this becomes critical.
The recommended wire is 32mm2 = heavy battery cable, and I think the copper core is too thick to fit a 50 amp anderson plug pin.

2. An Anderson plug can be ASSEMBLED in 2 ways.
One way causes massive resistance and over-heating when 2 plugs are clicked together. The other is the right way.
Both ways will seem to work correctly - until you feel the wires, or
smell the burning insulation.
As you probably guessed I managed to assemble them the wrong way first.
Put simply, the thick pins must be pushed up near the front of the
plug. Takes some effort, and you will hear 2 clicks during ASSEMBLY.
When two plugs come together, the thick pins must interlock.
These carry the current.
Now for the wong way : When you ASSEMBLE the plug, if you only push
the thick pins onto the sping clips (eg one click), when the two plugs
come together the SPRING clips will click and connect.
These are NOT supposed to carry current, and of cource will overheat and drop a huge voltage.
With my inverter plugged in, it worked OK then gave error beeps.
I felt the Anderson plugs & they were VERY hot - as were the wires.
Fortunately they were beside me, not out-of-sight in the trailer plug.
If you have never ASSEMBLED an anderson plug before in your life, it is
worth knowing it can be assembled incorrectly.
Hope this helps....regards......

For those interested,
Jaycar Electronics have the 30A Anderson plug at $7.95 a pair and 120A at $19.95 a pair.

Phil I