Hi all,
I have a question about where to bond earth and neutral …
Looking to do a multiplus 2 with grid connection…
I plan on using a gfci : residual current device to supply the multiplus
Looking to do battery backup too - so when the power goes out , power supply occurs etc
Also using gcfi’s / rcbo’s on the supply circuits in the house…
My question is - where should the earth neutral bond be done ?
My first thought is before the Multiplus on the supply side, but doesn’t the Multiplus disconnect the relay when the grid power is out ? Meaning it would loose grid connection and loose its earth neutral bond ?
Obviously I’m disabling the earth neutral relay in the multiplus
Does the neutral stay connected on ac in regardless of grid supply ?
I would strongly recommend to read the important baseline documents - including grounding, neutral and earth link - provided by Victron before you install your system.
So, where should (or should not) RCD’s be used. In the examples shown, in a house environment, the load is most likely compried of several RCD protected circuits such as power points/lights/cooking equipment etc. Is it reasonable to install RCD’s in a downstream environment like that.
Also on the upstream side, should an RCD be used in place of the fuse shown.
Hello @ShallowAl . Interesting question Cascading RCDs requires at least the right RCD types in terms of current and trigger delay. In the diagram attached (sorry for the german text, source ABB), you see a main RCD (in your words, the upstream RCD) and a cascaded RCD. The two curves and its areas should never interfere to avoid a double release. That’s the general part of the story from my point of view. Main RCDs as first ones in the cascade are “S” types (selective).
It would be interesting, if Victron has a specific recommendation regarding RCDs between grid and the inverter for specific reasons
In my own system, there is no RCD between grid and inverter, but separate RCDs on AC load side of the inverter. For parallel loads, I have additional RCDs for my Wallbox and the bigger loads in the house.
Thanks … I have read that and it’s quite good explanation…
When I did my off grid cabin(no mains - only a multiplus - also ac coupled with a fronius) , I relied on the Victron men relay, as per txt book install … I had a rcd nuisance trip about once per month - every month… almost like there was some software process that dropped this relay briefly once per month…
I ended up doing a switchboard men link and disabled the men relay and never had a issue since…
I plan on converting my house soon to have dual multiplus units for backup and night time battery use - cause Australian feed in tariff isn’t worth it any more and power prices are sky rocketing…
I like the idea of a hardwired earth-neutral link and not relying on a relay, however I know code is to have the men link at the first point of supply… - this is what sparked my question…
I also like to use rcd’s for every single breaker for safety…
I’m also guessing you can’t have 2x physical men links ? One before and one after the inverter ?
You can’t have two physical links, because then part of the N current would bypass one of the RCDs because it would go via the PE link between the two links, and that’ll trip your RCD instantly.
Cascading RCDs requires at least the right RCD types in terms of current and trigger delay. In the diagram attached (sorry for the german text, source ABB), you see a main RCD (in your words, the upstream RCD) and a cascaded RCD. The two curves and its areas should never interfere to avoid a double release. That’s the general part of the story from my point of view. Main RCDs as first ones in the cascade are “S” types (selective).
