# Is iotawatt compatible with my requirement

Can I monitor the energy consumption for my hvac that runs on 3 phase supply?

If you could please let me know if iotawatt would meet my requirement, I’ll then order the parts immediately and hire a skilled electrician for installation.

I’m not an electrician/electrical engineer. I read the documentation but it’s not clear to me if the system can monitor power across 3 phase?

So I have a 3 phase power supply, I then have 8 single phase circuits that I want to monitor And also 2 A/Cs that run on 3 phase power. I’m not sure whether iotawatt can track the ACs

IoTaWatt can measure three-phase by one of two methods:

• Direct reference, where three voltage reference transformers are installed with three receptacles each on a different phase.

• Derived reference where a single voltage reference transformer is installed in a nearby receptacle. Virtually all residential three-phase users use this derived reference method with favorable results.

With derived reference, up to 14 circuits can be monitored. You have described 8 single-phase circuits plus 6 three-phase circuits for a total of 14. With the mains, the total is 17, so not everything can be measured with one unit.

There are several ways to overcome that limitation:

You can elect not to measure the mains. You can define an IoTaWatt output that is the sum of all 14 branch circuits which should be very close to the main power.

Similarly, you can elect not to measure one of the AC units and define an IoTaWatt output that is the mains minus all of the other loads, which should be very close to the unmonitored AC load.

You can combine each of the phases of the two AC units to measure the total AC load.

You can elect to not measure any other three loads, and IoTaWatt will calculate the total of those three by subtracting the measured circuits from the mains.

To measure the mains, you would need 3 100A CTs. All of the other circuits would use 50A CTs. You would need 11 or 14 if combining the AC units. If you combine the AC units, you would also need three headphone splitters.