I'm currently working on a project to monitor an air source heat pump (a Dimplex LA MI model) which is inverter driven. I suspect this is chucking a lot of harmonics out. I can hear high frequency buzzing coming from the dedicated consumer unit fitted to supply it.
How well does the EmonTX v3 deal with monitoring loads which high harmonic content? Has anyone had any experience of this?
My gut feeling is the current sampling method will work and provide a decent indication of power.
Re: Monitoring power consumption of inverter driven heat pump
I have not tested the ac-ac adapter (voltage sensor) at harmonic frequencies, but I have tested the YHDC c.t. (see the report). The basic sample rate is about 2500 per sec so it should be good to the 25th harmonic. From memory that is around the maximum frequency that a tariff meter is required to measure. There should be filters that clean up the current drawn by the inverter, so very little energy ought to getting out at those frequencies anyway (it's probably magnetostriction in the filters that you're hearing) so accuracy should be largely unaffected.
Re: Monitoring power consumption of inverter driven heat pump
Thanks Robert.
I'll give it a go and see how it works. At the moment any energy monitoring is a lot better than what it currently has (none at all)...