question

jason-nz avatar image
jason-nz asked

BMV-712 Relay conditions for low voltage generator start

Hello,


I have a BMV712 smart, CCGX and 3 x Quattro 24/5000/120's/

I have an Cummins Onan generator - with a pulse start relay I have built (to mitigate starting). Currently the inverters start the generators absolutley fine on high load automatically if required on one phase.

I would now like to achieve the simple task of having the BMV-712 monitor for low voltage and start the generator - keeping it on until the voltage reaches our charge voltage.

Steps I have completed:

1. Log into the BMV-712 via bluetooth

2. Navigate to the relay screen.
3. Leave all settings default but change Low Voltage Relay - from disabled to 22 volts.

When the battery bank hits 22v, the relay starts the generator successfully. However after a short time of approx 1 minute, the generator turns off.

QUESTION: What additional settings do I need to change to have my relay start the generator on at 22v and leave it running until it charges fully and then shuts the generator down?

Thanks in advance.

Relay
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3 Answers
harold avatar image
harold answered ·

Hi

I think it switches off because the relay / alarm is cleared by the higher voltage during charging.

Wouldn't it be better to trigger on/off on SOC instead of V?


Harold

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jason-nz avatar image
jason-nz answered ·

Haha, such a simple answer which makes perfect sense now. Thanks for that.


So % charged rather than voltage?

1 comment
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harold avatar image harold commented ·

Yes,
I don't know what type of battery you use, but my setting is start at 50% SOC and finish at 90%

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enrique-marquez avatar image
enrique-marquez answered ·

Hi @jason_nz you can use the option Relay-off delay, you can set a minimun operating time. You can a high consuption continuous in AC and the voltage drop but the SOC is at 70% for example. Also you can use option Minimum close time for no start very quickly.20200415_222931.jpg


20200415-222931.jpg (255.0 KiB)
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