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ejrossouw avatar image
ejrossouw asked

What exactly does "Has DC System" mean and when is it required?

Dear community members

I understand from the manual the Has DC System option is used if one has for example a wind generator in addition to e.g. a smartsolar PV charger. So, for sake of clarity. I have a smartsolar which is of course DC, but nothing else so do I keep it off or why will I need it?

Secondly, DVCC, I turned it on to ensure the correct control of the Smartsolar charging parameters from my BlueNova BMS and more accurate readouts from the BMS to the Colour Control GX. Is my interpretation of the manual correct?

Finally, Shared Voltage / Temp sense is in my view best left turned off as the BMS should have the most accurate information being embedded in the battery? What do you think?

Thank you for your thoughts and experiences on the matter.

Kind regards

Etienne

BMSDVCC
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5 Answers
boekel avatar image
boekel answered ·

Has DC system is for when you have DC sources or users that are not connected to the Venus, like if you have a wind generator connected to the DC bus. The Venus calculates the difference between what is used / provided by the connected devices and what the BMS (or BMV) is reporting to be DC use / source.


DVCC is indeed needed to let the system use the data provided by the BMS.


Shared Voltaged / Temp sense: I don't know the details about that.

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Murray van Graan avatar image
Murray van Graan answered ·

For bluenova specifically, turn off the shared voltage and temperature sense. Turn on the dc system option only when you have an additional DC charging source

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mihair avatar image
mihair answered ·

Besides what was explained above, you will also need "Has DC system" button activated on CCGX in case of any DC load connected to DC bus.

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hominidae avatar image hominidae commented ·
As the standard installation is to connect the GX, like a Cerbo, to the DC bus, this should be set to "on"?
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Alexandra avatar image Alexandra ♦ hominidae commented ·
@Hominidae

While they are connected to the DC, and do use power, they are not DC consumers. The has DC is referring to DC aplliances or other chargers not integrated.
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maartenvt avatar image
maartenvt answered ·

From Cerbo GX manual:

"Enable this for boats, vehicles and installations with DC loads

and chargers - in addition to Multi and MPPT chargers. This

won't be applicable to most off-grid installations; and any

discrepancy between the DC current measured by the Multi, and

by the BMV, will be attributed to a 'DC system'. This may be

power-in from an alternator, or power-out from a pump, for

example.

A positive value indicates consumption. A negative value

indicates charging, for example by an alternator.

Note that the value shown will always be an approximation, and

is affected by the variation in sample rate between elements of

the system."

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Alexander Sucker avatar image
Alexander Sucker answered ·

So I can use this, to monitor the drawing of my hoymiles? Which sensor do I need for this purpose?

I can't get the values from OpenDTU in there.

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Alexandra avatar image Alexandra ♦ commented ·

@Alexander Sucker

No, they are micro inverters.... So they produce AC from the solar panels. You would need an AC meter like a Carlo gavazzi or ABB maybe.

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Alexander Sucker avatar image Alexander Sucker Alexandra ♦ commented ·
Yes and no. It produces AC, yes, but out off the battery, which is charged by a MPPT.

The AC production I see via the OpenDTU in my VRM, but not the DC drawing. And the PV value counts double, because it adds the MPPT and the hoymiles.

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