RCD choice for an inverter

[omega015]

I have an inverter (Victron Multiplus 2 48/5000) that is currently fed from a 50A RCBO however it doesnt give me any selectivty when downstream circuits fed by the 30ma RCBO's trip, so I would like to swap these out to MCBs and potentially give additional protection via 100ma / 100ma Time delayed rcd's. Manufacturers instructions state these should be protected by a fuse or mcb so theres no issues from that side.

Would this be acceptable (despite the limited informaiton you have been given at this time)? Would you recommend a different route? Thanks in advance for your feedback.

Current setup:

Proposed setup (changes to mutiplus feeds in Garage DB and MP DB):

I also need to install an earth rod for this installation as it's PME and cannot be relied upon upon a grid down situation. I just need to figure out where on earth (pun intended) I can install one around the house or garage and run the cable back to the MET as all around the house is poured concrete and services run along the side where everything would naturally be best to place a rod.

 

[flameport]

Why do you need any RCD for the connection to the Victron devices?
What do you think an RCD is protecting there?

 

[omega015]

To protect in the event of a victron malfunction, fire I suppose? e.g. moisture, bugs or rain got into them being located into a garage. I know this wont give any valid shock protection but didn't think it could be a bad idea to add a little additional protection for this part of the installation.

Do they offer no further protection to the installation at all and would they only be a negative thing to add ? Would MCB protection only be suitable for them? I have read various other posts and some mention IET CoP for ESS and the need for RCD but I dont have that guidance to refer to so am unsure.

 

[ericmark]

My inverter states use type AC RCD, and where to fit it, is not yours the same?

 

[omega015]

My inverter states use type AC RCD, and where to fit it, is not yours the same?

It does have a guidance to this as below:

• AC-In
The AC input must be protected by a fuse or magnetic circuit breaker rated at 32 A (for 3 kVA model), 50 A (for 5 kVA
model) and 100 A (for 8 kVA and 10 kVA model) or less, and cable cross-section must be sized accordingly. If the input
AC supply is rated at a lower value, the fuse or magnetic circuit breaker should be down sized accordingly.

• AC-out-1
An earth leakage circuit breaker and a fuse or circuit breaker rated to support the expected load must be included in series with
the output, and cable cross-section must be sized accordingly.

 

[ericmark]

I did not install it, it does say

with a work hunt for RCD, no results for MCB or over current. It seems unlikely any standard MCB will work on the magnetic part with the output from an inverter.