TriMetric 2020/2021 shunt - 100 or 500 amp?

[ostream]

Can anyone share the practical differences between using a 100 amp or 500 amp shunt? The manual states with the 100A/100mV shunt: measures 0.01 to 250 amps. With 500A/50mV shunt: measures from 0.1 to 1000 amps.

Seems either would work equally well for typical Airstream usage. Does multiple batteries make a difference? Multiple solar panels? I noticed the newer 2021 bundles the 500 amp shunt.

Comments?

Thanks in advance

[87MH]

Originally Posted by ostream

Can anyone share the practical differences between using a 100 amp or 500 amp shunt? ...Seems either would work equally well for typical Airstream usage. Does multiple batteries make a difference? Multiple solar panels? I noticed the newer 2021 bundles the 500 amp shunt.

I hope 68 Overlander (Randy, with Best Converter) chimes in here, but I believe that the 100 amp shunt will give you more accurate readings at the lower end of the scale.

I recently installed a 500 amp shunt on the Sovereign, and I wonder if I should have gone with the 100 amp, since I don't think I will ever see much of a draw over 40 amps, and most of the time I should be in the 2 to 10 amp range.




I installed the shunt on the Negative Post of the group 27 AGM battery as close to the battery as I could locate it.

[letsgo123]

The shunt that should be used for accurate readings should place the meter reading at the half way point of the meter scale. therefore an anologe meter that is to read 40 amps would require 100 amp meter scale with 100 amp shunt.

your meter is only measuring voltage drop across the the shunt it self
(approx. at 100 amp reading the voltage drop would either be 100mv or 50mv or 5mv).

If you have a multy meter and measure current, your meter range selector, is selecting a different shunt, but the maximum voltage drop that the meter action reads, can never exceed the 100mv or 50mv or 5mv (every meter is different).

The high end meters have a circuit load of 22meg. ohms, use only on electronic circuits.

[boondockdad]

I'm with 87.. I didn't think I'd need readings over 40-50 amperes.. so I went with xx.xx accuracy... although I'm not sure the extra hundreth makes much of a difference