where to install ammeter in solar system

I installed a combo amp/volt meter between the controller and the batteries. You could install another between the panels and the controller, but I don't know why.
Install in pos or neg line, but the combo meter must be in the neg line. Make sure to use a meter that is small enuff to display 1 digit after the decimal point. A 0-100 meter will not work good to show 1-3 amps.

The placement of th ampmeter depends on what you want to know, and what kind of regulation you're using. On my small system, all I want to know is how much current is being produced by the panels, so I place the ampmeter in the positive lead coming from the panels (negative lead would also work). I also have a voltmeter across the battery to see if I'm maintaining the proper float voltage after full charge. In the case of my MPPT converter, I monitor the amperage from the panels, the amperage to the batteries, and the float voltage. I use two 250 watt panels in series that produce a total of 60 volts at full production (500 watts. As the current demand deminishes, the current from the panel goes down, and the voltage creeps up to about 80 volts. I preferred the higher voltage configuration to permit the use of #10 AWG wire without significant voltage drop from the panels. The current can go as high as 45 amps to the battery so I use #6 AWG on a short run from the converter to the battery.

Hi,

I'd encourage you to consider a Hall Effect ammeter. They cost a little more but have no shunt.

Between the controller and the battery. The shunt typically installs in the ground side