Thanks for making us aware John.

Might be me but I can't seem to find the DPC on the BSI site; the IET portal just drops me onto the BSI Standards Development front page. Have you a link to the actual proposal by any chance, or should I just control my excitement and wait a few hours?

Yeah, I cant seem to find it also!

Not there, dates on page are not alligned to advertised and typical of BSi..

engx.theiet.org/.../should-all-rcbos-in-a-cu-db-be-bi-directional-and-dual-pole

Ditto, the BSI have it down as being in draft until the 2/7/24 and then Public Comments 3/7/24-11/9/24.

I don't know if something's delayed, if someone has put the wrong info on the BSI, or as is always my working assumption that I've just made a mistake.

Given I'm not the only one it's clearly more likely somethings changed/is wrong.

youtu.be/5WSqH9qatkI

Update regarding Amendment 3:2024 to BS 7671:2018

Thank you all for your comments. Unfortunately, there has been a delay with the DPC going live today. The team has been working with BSI to resolve this as quickly as possible, but it will likely not go live until tomorrow now (9 May 2024). We’re sorry for the inconvenience caused and thank you for your patience.

Just based on Mark Cole's video....

OK, I'm confused already (I know, with me it's easily done...)

First thought - does this cover my simple PV system? In the grand scheme of things power only flows one way - backwards - from the Inverter to the CU. So not bi-directional? At a more detailed level the inverter does draw a little power overnight (just to keep the grid fail monitoring and general logging going) - would such tiny amounts (<1W from memory) count as making it bi-directional?

Second thought was for inductive (or indeed capacitive) loads - with a power factor other than unity (1.0) - if I've understood AC theory correctly, some power flows backwards during part of each cycle (hence the difference between W and VA, or the so-called "wattless current") - so is it allowable to add up instantaneous power over a period (allowing some backward power to be cancelled out) before deciding whether the overall power flow is bi-directional or not? if so, how long? A single cycle, or perhaps longer - e.g. would a machine that mostly drew power, but occasionally used say re-generative breaking to push waste power back into the grid, count?

Maybe I've missed something somewhere (or forgotten what I already knew - that seems to happen more often these days) - but what are the physical effects we're trying to avoid with all this? If it's purely down to power flow it presumably doesn't matter if voltage is left on the "load" terminals when the device is open (otherwise we'd have caveats for devices connected in parallel or back-feed situations), and normal current flows in both directions anyway (on each half cycle), so nothing can be polarity sensitive in the conventional sense (like semiconductors) or the way an arc breaks.. . or can it?

   - Andy.

.Ah, something's returning... . was it something to do with the way T buttons are wired? Make the wrong assumptions and the test circuit connects the supposedly dead side to the supply with the device open and the button pressed?

&/

So is this an emergency amendment? As it’s the third amendment, does that mean a 19th is more likely to be sooner than expected?