Amtech MSDB modelling question

[ibra123]

Hi guys,

With regards to modelling a multi service distribution board, how would you guys model it in Amtech?

I have tried using a TPN distribution board and each circuit on the DB represents one apartment protected by a BS88 80A fuse (within the MSDB).

The error I am facing is "The disconnection time of the upstream overcurrent protection is lower than that for apartment circuits"

In my example I have a 400A cut-out (315A fuses) that feed my main panelboard, which then feeds my MSDBS with micrologics via 160A MCCB and then 80A fuse to each apartment which also has an 80A fuse at the apartment cut-out (henley red head series fuse).

Thanks in advance!

 

[pc1966]

That is an option even though that was not the initial design intent (at Stage 3) but wouldn't I need to double on the Distribution board/meter which would make it a lot more expensive?

Doh! Sorry too early, didn't realise this was the EV feed.

If the feed pillar has its own RCBO for each charger then I would be inclined not to worry too much about the LLPB/MPB selectivity.

But I would worry about the MCCB to incomer fuse selectivity. The loss of a fuse is a major inconvenience to 1/3 of the flats per fuse, as well as everything else, and not as easy to sort a flipping the LLPB breaker back on.

 

[ibra123]

The LV schematic has "250A TPN FUSE SWITCH DISCONNECTOR" shown between the MPB and the Landlor's CT stuff on LV212 feed.

Sorry that is just meant to be a switch disconnector for isolation purposes.

Just looked again, no incoming meter as LL has meter for feed, and all flats own meters.

Correct, each apartment is metered separately as well as a whole current meter at the Landlords Panelboard for Landlords supplies.

Doh! Sorry too early, didn't realise this was the EV feed.

If the feed pillar has its own RCBO for each charger then I would be inclined not to worry too much about the LLPB/MPB selectivity.

But I would worry about the MCCB to incomer fuse selectivity. The loss of a fuse is a major inconvenience to 1/3 of the flats per fuse, as well as everything else, and not as easy to sort a flipping the LLPB breaker back on.

Ok, I have actually managed to clear the error by changing the length of the cable from 20m to 10m for the landlords DB with a 100A MCCB. For the feeder pillar I have used a 63A MCCB.

 

[pc1966]

Ok, I have actually managed to clear the error by changing the length of the cable from 20m to 10m for the landlords DB with a 100A MCCB. For the feeder pillar I have used a 63A MCCB.

Good to hear you have a fix.

Shortening cables as a fix is odd, usually a longer cable drops the PFC/PSCC and so lowers let-through.

 

[ibra123]

Good to hear you have a fix.

Shortening cables as a fix is odd, usually a longer cable drops the PFC/PSCC and so lowers let-through.

Yep, I had the same reaction!