mtkhan

thanks guys. yeah I'm also struggling to see how you'd avoid a direct phase to ground fault immediately once you switch on main breaker since the red phase will then be connected directly to earth (via neutral bar bonded directly to earth in what I assume is a TNC-S earthing arrangement) and shouldn't this immediately should trip main breaker on overcurrent no? I've attached photos taken of municipal main breaker supply when it was still swapped incorrectly, and tried to sketch out the scenario as well where I do see there'll be 380-400V on the remaining phases with the red phase simply oppsoite polarity. But like you pointed out, I struggle to see the main breaker not trip immediately if this was the case. Thank you

Hi All. Theoretically, If there was an accidental swapping of red phase and neutral cables at the point of connection of a 3-phase 4-wire 400/230V system, what would happen downstream to 3-phase & single phase loads once power is switched back on? If we assume the system is fed from a standard delta-star 11kV/400V 1MVA municipal transformer. This was an actual municipal technician mistake! and it got me thinking what would've been the outcome Thank you

Firstly, really impressed by the insight on my first post on this forum, and and time taken by you both to respond to my query. Thank you. Ingo, regarding above, what does this entail both administratively and physically? Did you have to submit some applicaiton form to your munic and then they sent technicians out to your place and replace meter with a single-phase one? And then physically did the munic simply disconnect 2 phases and allow only one phase supply from meter to your main DB? Thanks both for all the other tips, will surely factor into the planning.

Hello All. My first post. What are the considerations I should keep in mind if I'd like to create one phase of my 3-phase munic supplied DB as a "back-up" phase, let's say it's the blue phase. My idea is to get my DB re-configured such that all critical loads are placed on the blue phase, while all non-essential and large loads e.g. geyser, stove, etc stay on the white and red phases. I know the trick is to for the electrician to balance the loads as best as possible. If I then get a single-phase battery inverter/charger installed with the inverter's AC-out connected onto the blue/back-up phase, and the inverter's AC-in coming from the white phase, will I effectively be bridging the 2 phases together when the inverter is working in bypass mode during normal munic supply conditions? My concern is then how do you prevent these 2 phases not being bridged at the munic supply side? Do you need to disconnect the blue phase supply at the main breaker, and only allow all grid supply to the blue-phase during normal operation to come via the munic supplied white phase through the inverter, obviously keeping in mind not to overload the white phase then? thanks in advance