I plan to use 2 of these to measure the output of 2 power supplies, 28Vdc and 12Vdc, and the respective currents to my test loads. The currents will be less than 5A in both cases. Some information I have found online indicates that this meter has an internal shunt while others indicate that an external shunt is required.

For my application, is an external shunt required?

The power supplies will also be used to power some indicators but I do not want that current added to the test load current I want to measure so I plan to connect the current lead after a switch but the voltage leads before the switch (would allow me to observe the voltage before connecting the load). I presume that the meter does not require current to flow through the ammeter circuit to turn on the meter and display voltage

I could not find a manual online and the only wiring diagram I saw was in the Amazon site and it also shows the external shunt.

Please advise

Mike