question

mannie avatar image
mannie asked

Multiplus in parallel not connecting on shore power

I have newly installed a system in my RV. I have 2 x Multiplus (24/5000/120-100) connected in parallel, a lynx distributor, SmartShunt 500A/50mV, 2 x MPPT 250/60 rev2 (v1.61) solar charge controllers for 1.6KW of solar panels and a 840Ah LiPO4 battery bank, this is monitored by a CerboGX (v3.10) and a digital multi control 200/200A GX.

I have checked the firmware on all devices is the latest version and have used VE configure to configure the 2 x Multiplus in parallel. Everything appears to be working well with the solar charging for the batteries and the Invertors are running well from the battery bank for AC loads. However when I switch on the shore power the Multiplus' recognise the shore power but trips the breaker after about 15 secs. I have checked the wiring and it all appears fine.

As a further check I have tried the system by making the master Multiplus a stand alone and then everything (invertor and charger) when switching on shore power is fine and there is no tripping. I have enabled the prioritise other energy sources in the advanced tab in VE configure so the charger switches to sustain mode as the batteries are currently at their sustain voltage so this is what I expected to see.

When I reconfigure the multiplus' back to a parallel system then it trips again. I have both the Master and the Slave configured with the same settings so wondering if this is where the issue lies.

Would appreciate someone pointing out my obvious mistake

Many thanks

multiplus in parallel
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2 Answers
iammotorhomeless avatar image
iammotorhomeless answered ·

@Mannie my first guess would be your AC input current limit
what size is the breaker and is it an RCBO breaker ?


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mannie avatar image mannie commented ·

Many thanks for your reply. I have the current limit set at 8A for the master and the slave giving a combined 16A when in parallel. As a standalone I had the multiplus set at 16A. The overruled by remote is enabled on both the Master and Slave configuration. It is 32A RCBO and there is one for each invertor and both are being tripped in the parallel configuration. There is a 'clunk' internal noise from the invertors and the RCBO trips after about 15 secs.

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dbollardini avatar image
dbollardini answered ·

Hey, have you found any solution ?

Having the same parallel config problem exactly when i plug in shore power. The earth RCD in Input Side break after a short time when clicking earth relais. Wiring and all checked several times. Standalone Config works well always.
Dino

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