Grid-tie disconnect for interlock? Possible Shunt Trip breaker? SolarEdge W/ XW+ 6848?

jgilly69

New Member
Joined
Jan 5, 2021
Messages
12
Ok so I have this new install question for at my house so if any of you electricians or solar installers could help ?

I have a grid tied solar edge feeding main panel. I want to install a new SE XW+ 6848 as backup and grid tie.

The problem is I do not want, nor would I have a need for a backup loads panel since I can run my whole house on the SEXW+ if needed? I want to install a shunt trip main breaker in my main panel for the main disconnect, and shunt disconnect breaker for the SE GRID , and a contactor for the SE LOAD? I would really like to use the same conductors from the panel to the SE? I have considered just doing a manual interlock for a backup breaker (SE LOAD) and a double throw disconnect to pull from SE GRID to SE LOAD?

Once the grid goes back up I would manually turn on and reset?


Any thoughts? I guess I really just need a automatic transfer switch but finding one to pull my main panel on and off is crazy?
 

Hedges

I See Electromagnetic Fields!
Joined
Mar 28, 2020
Messages
9,169
Do you mean controlling two shunt-trip breakers to serve as transfer switch? Sounds to me like malfunction of control signals could result in SE XW fighting the grid. Mechanically interlocked or proper transfer switch would be safer for your hardware and the utility workers.

Manually interlocked main breaker and backfeed breaker is one way. I have that so inverter can feed the main panel.

If you're lucky and have a main breaker at meter separate from main breaker panel, then you can install something in between.
Otherwise, consider adding a protected loads panel downstream of SE XW for things you want automatically backed up (phone and refrigerator?) and manually switch interlocked breaker if you want to power other things.
 

jgilly69

New Member
Joined
Jan 5, 2021
Messages
12
Do you mean controlling two shunt-trip breakers to serve as transfer switch? Sounds to me like malfunction of control signals could result in SE XW fighting the grid. Mechanically interlocked or proper transfer switch would be safer for your hardware and the utility workers.

Manually interlocked main breaker and backfeed breaker is one way. I have that so inverter can feed the main panel.

If you're lucky and have a main breaker at meter separate from main breaker panel, then you can install something in between.
Otherwise, consider adding a protected loads panel downstream of SE XW for things you want automatically backed up (phone and refrigerator?) and manually switch interlocked breaker if you want to power other things.
Thanks, Sadly yes I had to install a new all in one MSE so I am stuck with finding a method to pull the panel off grid. Most shunt trips are 110v so just thinking that I could put it on the Load side of the SE and it would actually power the disconnect? But yes one small error and it would fry the SE XW+. I can get a new main breaker with a shunt trip....Maybe I am just barking down the wrong tree?
 

Hedges

I See Electromagnetic Fields!
Joined
Mar 28, 2020
Messages
9,169
A panel like this one, you could rewire critical loads into. It is interlocked so you can use your XW+ to drive it, or bypass the XW and drive from main panel.


You can also put a backfed breaker next to your main breaker and interlock them. That will let XW drive everything on main panel.

I've done both of those with my Sunny Islands. But the "protected loads" is a wire run to another panel for my entire house. I replaced the 100A and 30A breakers in the generator panel with 70A and 70A.

There are other panels available with SPDT and DPDT transfer switches so individual circuits can switch between "critical loads" and your main panel.
You probably have loads that are excessive for running entirely off PV and battery, so useful to manually enable them and know you're using backup not grid. I plan to automate that eventually so I don't run battery empty without knowing there is a grid failure.
 
Top