DIY power meter.

Built this a few years ago so I can monitor power of various things without having to rig up a couple of multimeters and clamp meters.
The meter itself shows volts, amps and watts. It’s actually a very versatile meter and you can program it to trigger things when certain perimeters are dropped bellow or exceeded. The display looks a bit strange on camera because it is multiplexed and the camera has caught the refresh.
Usually plugged right into the output of the Variac and the voltage seems to be quite accurate. Let’s me get very fine control of it.
It doesn’t like very small currents of less than an amp but you’d expect that as it’s really designed for hundreds of kw lol. In fact it has a MW scale, I imagine you’d need a beefy CT for that lol.

Switch on the front controls the output contactor and the big red indicator shows when it’s energised. The switch on the side is the main switch for the meter. Currently showing zero as it’s not plugged into anything.

I’ve used big 20amp C19 & C20 input and output sockets and I’ve got a few leads made up with a standard plug socket, quick test connector and a standard C13 kettle plug on the ends.