Wife up Victron System with Heatpump

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sesshoumaru asked Sep 3, '22

Wife up Victron System with Heatpump

Hi @ all

I want to add a headpump to my home, runninng a Victron Sytem (3P Quattro + 8xUS2000C + Fronius Iv). Ideally I would want to run the heatpump via PV energy. In case there is not enough PV I would like to get the energy from the grid using a special tariff with requires a dedicated metering.

Here the problem starts. How would I have such a heatpump connected electrically. I don't want the meter to run if my own PV power is used, but I want it to run when there is not enough PV and the difference drawn from the grid. I guess the heatpump has to be on the AC-in side of the Quattro, but I would really appreciate if somebody with experience could enlighten me how heatpumps with own meter are usually connected to PV system or a Victron system in generel (Heatpump will be Daikin Altherma).

The only thing I can image is using a ATS switch, so that in summer i can run it on PV on my normal tariff, whilst after transfer by ATS is uses the special meter wiring. Which probably is bogus, right?

MultiPlus Quattro Inverter Charger

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Answer 1 · 2022-09-03T18:17:00Z

Mike Dorsett answered · Sep 03, 2022 at 06:17 PM

The transfer switch is in the Quatro already, but if the quatro / pv system is required to run anything other than the heat pump, then you would need an external transfer switch (or 2) as well. The Quatro woud also have to be set up not to charge the battery from the AC whilst on the special tariff.

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sesshoumaru commented · Sep 04, 2022 at 01:50 PM

Thats not my usecase.

I have the Victron System to run the entire house. Meaning that on AC-1-in is the grid, on AC-2-in an emergency power generator, on AC-1-out the actual critical loads and on AC-2-out the non-criticals like kitchen oven, washer and dryer.

In there would like to add the heatpump to this system. Which brings up the question how heat pumps with own tariff meters are connected to a PV system in generel.

Aim: Use power from solar when sun is up, use power from grid when sun is down (not draining the battery of the victron system).

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vpvh.png (35.2 KiB)

Answer 2 · 2022-09-04T20:36:28Z

sharpener answered · Sep 04, 2022 at 08:36 PM

Perhaps you could use an Eddi diverter to sense whether there is enough power being exported to run the heat pump, and use that to connect the hp to AC-Out with a changeover contactor or relay. (IIRC you can program the Eddi with hysteresis to take account of the hp's own load)

If there isn't enough surplus PV then it would draw direct from the grid via the meter.

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Answer 3 · 2022-09-11T15:29:24Z

sesshoumaru answered · Sep 11, 2022 at 03:29 PM

I learned from my power provider that I have to install another power meter (consumption only) behind the providers current power meter (consumption and feed-in) which measures the energy going into the house (aka Victon System). Between those two meters from the provider (sealed and so) the heat pump will be connected.

This way the power provider can distinguish how much power the heat pump uses and how much the house. For the heat pump I will get a special lowered tariff. Now I just have to add a EM24 to the heat pump line and add it as AC load to the Cerbo GX. Now the GX should know about the consumption and "press" enough PV up the line, if there is any, to this AC load. Pretty clever.

I might still put an ATS in the way of the heat pump, in case of net failure to switch to the victron island - hopefully never needed.

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Answer 4 · 2022-09-12T08:32:26Z

Jason - UK answered · Sep 12, 2022 at 08:32 AM

@Sesshoumaru What you have described is basiclly the system I have. My ASHP is timed to do the hot water generation once a day at 14:00h, the time my PV output is at its peak. With a 5.7kW PV array, the PV generally is more than sufficient for my ASHP and also to charge the batteries. I have a Mitsubishi Ecodan WM85 which pulls about 1kW for heating (45*C max flow temp in heating). In hot water mode, it pulls about 1kW until it needs to get the flow temperature above 50*C, then it ramps up to pull about 3kW for the final temperature lift. Either way my 5kva inverter is more than enough to run my ASHP if there is no PV. If you take a look at my VRM link below, you can see for the last 4 months, my heat pump kicks in at 14:00h, but pulls no energy from the grid. For the winter, I'll be doing both the hot water generation and battery charger on my off-peak tariff at 7.5p/kWh and that way any solar generation during the day supplements the inverter in proving the heating.

I have a schematic of the AC side on my electrical distribution in the photos if that helps.

https://vrm.victronenergy.com/installation/171934/share/db6807bb

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sesshoumaru commented · Sep 12, 2022 at 05:16 PM

I think I understood how to do the wiring, but I still would apprecated wiring examples.

Nice overview. Maybe I add a MPPT RS 450/200 next year just to get more from the sun.

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