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Evgeniy Labunskiy avatar image
Evgeniy Labunskiy asked

Viessmann Heat Pump Smart Grid Control using Cerbo GX

What I have

1. Viessmann Air-to-Water Heat Pump with Vitotronic 200 wo1c control module. It supports Smart Grid. It operates using 2 connections

Combination of On/Off states of this connections control heat pump performance. For example if C is off and D is off than pump in standard mode, C on D off - compressor off mode, etc. So basically I can tell to heat pump than I'm on batteries (no grid) and stop generating heating. Or if solar production is high and overcome grid consumption to heat water +10 degrees.

2. I have multi rs solar + cerbo GX

The question is: can I setup control system with cerbo that can implement such scenarios? Anyone has any guidance?

cerbo gx
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3 Answers
Evgeniy Labunskiy avatar image
Evgeniy Labunskiy answered ·

How do I see it: I can control relay ports from Nodered. If grid = not connected than I can make relay to on state, etc. the question is if this relay is compatible with relay on heat pump

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Duivert NL avatar image
Duivert NL answered ·

hi cerbo relays are just contacts, als long as you respect the specs of those relays you can control anything

from cerbo gx section 20.1 https://www.victronenergy.com/upload/documents/Cerbo_GX/140558-CCGX__Venus_GX__Cerbo_GX__Cerbo-S_GX_Manual-pdf-en.pdf

relays: 2 x NO/NC DC

up to 30VDC: 6A DC

up to 70VDC: 1A

AC: 6A, 125VAC

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Evgeniy Labunskiy avatar image Evgeniy Labunskiy commented ·
Need to check with Viessmann cause I cannot find voltage requirements for pins on their end
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sharpener avatar image sharpener Evgeniy Labunskiy commented ·

They are described as "floating contacts" so I would expect their functionality is the same as the ESCO terminals on the Vaillant HPs. Voltage free contacts as specified for control by German utilities.


I am planning to use the Aux relay contacts on my MuGX for this purpose when my HP is installed, hopefully next month, see this thread. The relay is already tested and working with the Assistants, no Node-Red required. Also I can drive indicator lights and an acoustic warning for grid failure from the open collector Aux Out on the Multi.


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Evgeniy Labunskiy avatar image Evgeniy Labunskiy sharpener commented ·

As I found in docs for another solar system you also have to use some relay in the middle to correctly connect GX to Pump https://enphase.com/de-de/media/10458

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Duivert NL avatar image Duivert NL Evgeniy Labunskiy commented ·
from the screenshot you provided, it looks like connection B X3.1 is an phase connection, so i assume its 230v


in order the get it to work safe with the cerbo relays, you will need power relays in between the cerbo relays and the input on the heat pump

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Evgeniy Labunskiy avatar image Evgeniy Labunskiy Duivert NL commented ·

Looks like you are right. Something like this according to this manual

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Duivert NL avatar image
Duivert NL answered ·

thats an expensive solution i mean something like this, 2 pieces:

1717588425054.png

the cerbo controls this relay and then this relay controls the heatpump


1717588425054.png (242.8 KiB)
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