how will a supply meter react to burst mode power usage? I have a 4KW PV system and a 3KW immersion heater that I am planning to control using a proportional controller that can use either phase angle or various burst modes. Using phase angle will presumably lead to RF interference and thus require additional filtering. In burst mode at say 25%, although the average power used will be 25% of 3KW, but will the supply meter register the full 3KW bursts thus negating my attempts to ballence the loads?
Thanks for all you inspiring contributions.
Robin
Re: Phase angle or burst mode?
It all depends upon what supply meter you have fitted, as not all meters measure 'real power' in the same way, as I understand it, some meters average over one complete cycle (which would not work for burst mode), whilst others measure an average over a number of cycles.
The difficult bit is getting the technical info on the meters, as most manufacturers do not disclose this level of detail for fear of people using the info to hack the system, and I also understand that different companies like 'MeterPlus' have access to the firmware and can introduce specific 'regional' measurement rules.
The only way I found I could check was to actually test it, by connecting the load, and counting the meter LED flashes over say 6 minutes (usually it's one flash per Watt/Hour) and multiply by 10. This will give you an idea of how your meter will record the load.
I checked mine with a 99p Maplins diode in series, and it records exactly half load (and as it switches at zero crossing, there is very little heat and no noticeable harmonics on the resitive load, effectively halving the power.)