UKPN unreasonable charge for 3 phase upgrade, but single phase upgrade free?

[-rick-]

That is my point. The system is running off single phase and transferring the energy between phases (via the DC battery bus). Lose a bit of efficiency but as long as total draw is below the input capacity of the inverter connected to the mains minus the efficiency loss it should run forever. The battery also proivides a reserve for temporary load spikes above the capacity*. Would want soft start on equipment though I'd guess.

 

Anyway I'm not 100% sure Victron can do it but I thought I saw it mentioned in their docs. I know people do similar using big VFDs (instead of one per machine, get a big one and have it generate 3 phases for the shop). But I believe that has downsides, you absolutely need to understand the details and wouldn't be a recommended route.

 

*The Victron Multiplus series can generally run at 2x rated for short periods without sweating.

 

If your compressor is the main draw, why not put it on a VFD and run it off single phase? Even if you put in a way to generate 3-phase for everything else, at least it would reduce the overall load on that system saving cost.

[Alan Ambrose]

@NCXo82ike - if it’s any consolation, I’m finding UKPN laughable. I kicked off our install in January. It’s the simplest install of 5m cable from the verge outside our plot to our kiosk, just inside the plot. We’re on a single track quiet lane. Single phase only. We dug the trench and installed their special duct months ago. It should get installed in early August - that is 8 months later. They’re planning to close the road for 2 days for what will be a couple of hours work max.

 

My most recent conversation:

 

Me: I can’t think it will take two days - the whole route is already dug and ducted all the way to your mains cable and has been ready for months. Your guy on the ground has seen it several times, you really won’t need to start with an excavation team for 1/2 a day.

 

UKPN: is the excavation already open? I advise you to fill it back in so my team can excavate it again on the day.

 

Me: OK. (Thinking, I’ve inadvertently fallen into a major role in a play written by Kafka with help from Beckett, Checkov and Orwell.)

Edited 14 hours ago by Alan Ambrose