Forums

Utility cutout transfer time

Utility cutout transfer time

Just wondering if anyone knows the transfer time between when the grid goes down and the inverter kicks on without solar input. And a bit further on that the time it takes to reconnect to the grid when it comes back and is that adjustable? Specs seem to be very limited from what I have found. Thanks

Patrick | 30 juin 2018

If you're asking about the grid disconnect function when using Powerwalls I've recently researched this topic in depth with early adopters and learned that the transfer time is almost instantaneous. Tesla has apparently nailed this functionality perfectly and it's IMHO it's a very big deal.

Just confirmed this info again last week via a live conversation with another forum member here in FL and he says the disconnect usually happens so fast they never know when the grid actually fails. The power to the home stays constant as the only effective change is the grid being removed from the system. AC from the internal PW2 inverter tricks the PV inverter into thinking the grid is still alive and connected, so the PV panels and primary inverter(s) just keep chugging right along as though nothing happened...

Apparently the Energy Gateway and the Tesla system software are the secret sauce here.

If you are asking about "transfer time" when the grid goes down with no PW2 installed, there is no such thing. Without an intelligent battery system with approved grid disconnects, for power company safety reasons the entire system will shut down when the grid fails.

Tesla-David | 30 juin 2018

When our PW2 system was installed last week the installer (A&R Solar) did two backup tests to see how well the PW2 system worked during a power outage, and @Patrick's response was spot on, it is instantaneous and you really do not even know that it switched over to PW2 from grid. One thing we noted though, is it is enough of a time lag to trip and disconnect our router, so we have to turn that back on, but everything else was seamless. We absolutely love our new PW2 system operating in self powered mode.

cwied | 30 juin 2018

I think the spec says something like .5 seconds. Just to provide a data point, I had a power outage last Thursday and it rebooted my routers and my NAS server. If sensitive equipment is on a small UPS, it''d probably be seamless.

nickflynn1977 | 18 juillet 2018

Thanks everyone for the replies. Apologies as I just read them this am as I had been waiting for an email from the forum that I had replies which I guess is not standard on here. Anyways..

My only other question if known would be how the unit processes reconnecting to the grid. The reasons for wanting to know are that where I live the grid utility has what are called auto breakers set up either at the substation or in line somewhere. These units cycle power on and off many times to see if a fault has cleared (probably something like a tree branch on the primary). Sometimes it will cycle 5 to 8 times in just a few seconds off, on off on off etc. As you can imagine the fridge, well pump, computers etc do not like this one bit! Not to mention my various new and vintage ham radio gear. I have lived off grid in a few places and all my inverters were able to select a reconnect time when grid power comes back usually preset at 20 or so seconds so that you could be sure the grid power had stabilized. I am hoping that the tesla system will at least take a few seconds to reconnect so I may avoid the off, on, off on cycling that is happening. I had the site survey yesterday and was not able to further clarify any of this with the guy who came out. Thanks!