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uguraladag asked

[solved] Cerbo gx relay contacts over-volted and stopped working

img-20231016-133617.jpgİn my Victron solar system ,I set the Cerbo gx's relay according to the Soc percentage, gave the min and Max values, and with a contactor connection, when the battery Soc drops to 20%, Blue smart IP 22 220/30 12 Volt 30 Amp starts battery charging. I set it to stop charging when it reached 40%Soc. It worked fine for a month. The current passing through the relay contact is I = P/V, I = 400/220 = 1.8 amperes. Since I don't draw more amperage from the relay, why doesn't the relay work? I checked the contactor and it works fine. What would be the reason ?

cerbo gx
img-20231016-133617.jpg (474.7 KiB)
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grahamwood avatar image grahamwood commented ·
I don't think you are supposed to connect the charger output to the batteries through relay 1 on the Cerbo. Not a good idea.

I auto charge the batteries when voltage goes below 25.5v but the Cerbo relay is directly connected to the Remote Start terminals on an IP43 charger. This way you are starting and stopping the charger as opposed to connecting and disconnecting the charge current to the batteries. You've probably broken the charger.

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uguraladag avatar image uguraladag grahamwood commented ·

I guess I didn't explain. When the Cerbo gx relay 1 contacts are closed, it pulls the contactor relay and feeds the 220 volt to the charger. When the charge reaches 40% Soc, the Cerbo gx relay 1 contacts open and the charger does not work. This cycle automatically continues between 20-40%.

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grahamwood avatar image grahamwood uguraladag commented ·
So you have hooked up a continuity meter to the terminals on Cerbo relay 1, manually switched the generator on and off through VRM and confirmed that the relay is not working?
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uguraladag avatar image uguraladag grahamwood commented ·

Yes, but for a month the system kept automatically starting charging and it was working great.

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pwfarnell avatar image pwfarnell uguraladag commented ·
What voltage do you have on the contactor coil. Additionally, do you have a freewheel / flyback diode across the contactor coil
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3 Answers
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uguraladag answered ·

I feed the contactor contacts with 220 volt Ac

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pwfarnell avatar image pwfarnell commented ·
But do you put 220 V ac through the cerbo relay because if you do then that is above the voltage rating of the Cerbo relay.
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kevgermany avatar image kevgermany ♦♦ pwfarnell commented ·
See the calc in the first post. Although unclear looks very like 220V through the Cerbo relay.
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kevgermany answered ·

It has a 125V limit.

As shown in the data sheet section you ringed.

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uguraladag answered ·

Isn't the power that the Cerbo gx relay contact can transmit P=V x I P(Watt) = 30 (V DC )x 6 (amp)=180 (Watt) { Written in user manuel }

yes, I understand now that I used (400W) twice the power that the relay can transmit, which means the relay may be broken... I understand my mistake now, I am wrong... I wish I did not use Victron. If the manual had written "Do not use power over 180 Watts on relays", I would have not made this mistake..


This was a bad experience for me...Fortunately, I have another relay2 contact to use :))) Let this incident be a warning to Victron lovers...

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kevgermany avatar image kevgermany ♦♦ commented ·
Victron equipment is intended for installation by suitably qualified and trained professionals. Seems that you didn't read the manual and don't have the necessary training. There's a Victron professional site which has all the training available. Registration is free.
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