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blue-sails avatar image
blue-sails asked

Can the Cerbo GX be connected directly to solar panels without solar chargers or an inverter?

Hello,

I am curious about connecting a Cerbo GX to solar panels.

What is required to do this?

I suspect current transformers are required.

Which current transformers? How are they physically connected to the Cerbo GX?

cerbo gxSmartShuntSolar Panelmonitoringdc meter
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Alexandra avatar image Alexandra ♦ commented ·

@Blue sails

I am assuming you mean particulary for communication and data recording specifically here? (Stranger questions have been asked)

You can use a smart shunt or bmv like a dc energy meter for the output of the mppt to the battery. That connects with VE direct to the GX.

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blue-sails avatar image blue-sails Alexandra ♦ commented ·

Hi Alexandra,

This would be mainly for monitoring, communication, instantaneous data, and past data.

So if I understand your answer a smart shunt or BMV between the (positive? cable of the) solar panels connected to the VE direct connector of the Cerbo GX without using a current transformer.

If I was to make a bill of materials, would it look like this:

  1. Cerbo GX
  2. Smart shunt
  3. VE cable
  4. Anything missing?

How many amperes and volts DC will this arrangement manage?

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wkirby avatar image wkirby ♦♦ blue-sails commented ·

1. Battery
2. Shunt (BMV or Smartshunt for monitoring battery current)
3. Charge Controller (MPPT).
4. Solar panels

Optional:
5. Cerbo GX
6. VE.Direct cables.

Cerbo GX is a data management internet gateway. It does not manage the electrical energy directly.

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blue-sails avatar image blue-sails wkirby ♦♦ commented ·
I have a direct PV system without batteries, inverters, or charge controllers.
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2 Answers
Kevin Windrem avatar image
Kevin Windrem answered ·

I would say no to direct solar panel to Cerbo connection. You need some amount of DC energy storage to maintain the Cerbo through the night (or cloudy skies). Plus the voltage from the solar array will vary substantially. Cerbo can tolerate a wide voltage range but ...

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blue-sails avatar image blue-sails commented ·

Can Cerbo with a shunt tolerate 300 VDC coming in from a solar array at less than 11-amps?


Can Cerbo accept an additional DC power supply from a small battery or power supply converter not connected to the solar panels to maintain it?

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Alexandra avatar image Alexandra ♦ blue-sails commented ·

@Blue sails

The DC power supply in the cerbo takes between 8v and 70v dc only. So designed to run off a battery based system.

See the datasheet.

You would need to use an energy meter like the carlo gavazzi meter for the AC PV to measure your AC in and out.

Does your PV inverter has something like a data card with modbus?

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Alexandra avatar image
Alexandra answered ·

@Blue sails

They are all designed for dc battery monitoring, not high voltage dc panel monitoring.

You will need to look more at other equipment not compatible to connectable to the cerbo.

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