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iammotorhomeless avatar image
iammotorhomeless asked

Multiplus II 48/5000 (240v) in Parallel and I am getting "High DC Ripple: Warning"

Hi
I have a pair of Multiplus II 48/5000 (240V) in Parallel and I keep getting a "High DC Ripple: Warning"

well I say 'keep gettting' it's happend twice, once when a high load switched off (kettle)
but also once when we were just ticking over at 300w

before some helpfull person says read the "Wiring Unlimited book".
I have, thanks !
the battery cables are short and a good size, and we did our best to make them all the same lengths

AND my question is:
what is the best way to monitor the system.

I don't know if it is relevant, but the slave seems to be louder than the master, (as if it's working harder) is there a way to monitor the out put of each unit separately ??

and/or is there a way to tell witch one is tripping the warning (master or slave)

Cheers


multiplus in parallelshutdownwarnings
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1 Answer
nickdb avatar image
nickdb answered ·

Get a clamp meter and measure the draw under various loads.

Are the inverters similar ages?

Ripple isn't usually a mystery:

Iffy wiring/connections, undersized cabling or batteries incapable of responding to load/surges.

With parallel systems short/low resistance cabling isn't a good thing, it can cause problems and is discussed in the guide for 3phase/parallel systems. It can contribute to imbalances.

One of the reasons parallel systems are an advanced config.

https://www.victronenergy.com/live/_media/ve.bus:4._ripple_in_a_ac_battery_system.pdf

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iammotorhomeless avatar image iammotorhomeless commented ·

the master is HQ2246 and the slave is HQ2241 so only 5 weeks between them

and sorry I used the word 'short' they are not short. they are about 1.5m to the Lynx and about 2m to the battery,

and thanks for the link... I had not seen that... but it is the same as in the "Wiring Unlimited book" :)

Is it possible to monitor both units at the same time with VEConfigure ??

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nickdb avatar image nickdb ♦♦ iammotorhomeless commented ·
Unfortunately not, it appears as one system. The initial clamp meter tests are important to check symmetry.

Those units are perfect for pairing, so if there is an imbalance it will be from something external. They will never be perfectly even anyway, usually 3 to 8% or so depending on load.

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