Hello robineicher
The main differences between "1PM Mini Gen3" (red) and "mini Gen3" (blue) are as follows:
- Both devices can switch a load.
- Red can measure the power consumption of the connected/switched device (PM = Power Meter) >> blue cannot.
- Red can only switch alternating current (110-240 VAC, 8A = max. 2000 watts).
- Blue can also do this (same as red 110-240 VAC, 8A = max. 2000 watts), but it can also switch a device that is to be operated with direct current (then the switching capacity is 30 VAC, 5A = max. 150 watts) >> and that is precisely why it needs the additional input.
Or explained differently: Red and blue are operated with the L/N connections on alternating current (this is the current that the Shelly itself needs to run). Red "loops" the AC current through from the L connection to the O connection (output). Blue does not do this, but is galvanically isolated internally. This means that only the current that is connected to the I connection (input) (either alternating current or direct current) is looped through to the O connection (output). You can find good diagrams and details on the Shelly page:
Red:
https://kb.shelly.cloud/knowledge-...Blue:
https://kb.shelly.cloud/knowledge-...