Transfer Switch?

[Cmy]

Utility wants a disconnect switch, no problem except my meter has three outputs. OK, find a 400 amp disconnect panel big enough to add dual three lugs out.

Just talked with an electrician and he said a transfer switch is also needed to switch from grid to inverter source. With the grid disconnected, won't a hybrid inverter continue to convert solar/battery to AC?

 

[NVS]

The transfer switch is to keep you from back feeding power out to the power company lines when power goes out. If you are send out power this could kill one of the workers trying to fix the power lines.

 

[rhino]

Which "inverter" are you referring to? Any that can sell back to grid are required to prevent any back feeding to grid when grid goes out.

 

[Hedges]

400 amp and three meter "outputs", I'm not clear on your equipment and configuration. Diagram with labels would help. Part numbers and data sheets in addition might be useful.

You haven't said which hybrid. Some have 200A feed-through.

A visible disconnect switch on bidirectional input of hybrid is good, likely no more than 200A needed.

Your inverter could go down; in that case a bypass is desirable. A transfer switch so loads panel can be fed from either grid or inverter is one way. Interlocked breakers in loads panel is another; some would allow 200A & 125A, some I think you could do 200A & 200A.

 

[Cmy]

Got a generator and aware of the disconnect grid before starting need. Thinking I would pull the disconnect before inverter working again.

Haven't pulled the meter but the expectation is a 3 lug adapter on the out poles. Two lugs feed a pair of interior 200 amp house panels. Third lug goes to a panel on an addition. Approximately 14k of panels and inverter planned on the addition leg. I am doing the S-A 15 or EG4-18kPV dance.

Would be nice to have one disconnect that could hold three out legs but didn't show in the first look at the catalog.

An error in my questioning a transfer switch is looking at a single line. Inverter out at one end of the third line that ends, through two CB panels, at the meter. This line and panels are independent of the two house lines and panels. So there is nothing for a transfer switch to transfer to, it becomes an auto disconnect or relay.

Grid up and the inverter converts DC to AC and back to the meter. Grid down, transfer switches to an empty contact, while PV/batteries keep the mother in law addition powered. Doesn't help the main house but the main goal is to offset summer load- plus outages are rare.

 

[Hedges]

Is your service 200A or 400A?

I'm upgrading my new place from 100A to 200A, and like my other one, it will have 200A main breaker only. Then Polaris connector to fan out to multiple breaker panels and disconnect switch.
This lets me have inverter provide battery backup to all panels (limited to about 100A pass through of my inverter system), or just some or none, with the breaker panels able to switch to direct grid connection (all have breaker interlocks.)

 

[Cmy]

400 amps in with each 200 amp house panel getting its own feed from the meter. The third feed comes off of the meter, and not house panels, and went to out buildings through a 100 amp panel. That was changed to 200 amps for the addition we added. So at least 400 and maybe 600 amps. No idea what is supplied to the meter.

I was looking at some of the block connectors and wondering if you could build your own splitter. Thanks, will check the Polaris.

 

[NVS]

Hi

 

[Hedges]

Is there a 400A breaker or disconnect? Or does it just fan out to multiple 200A loads?
I would think utility would want sum of OCP (or single OCP) to limit it to 400A, or whatever they can feed.

I'd think you'd install a 200A fused disconnect and put a SolArk or whatever inverter with 200A pass-through in-line with one panel, or as another connection but output switched to drive one panel. Or both panels. All of which are the same thing if all load panels have interlocks or transfer switch to select between grid and inverter.

It would be convenient to have the option of powering any load on the property from inverter, but it is up to you to manage loads within it's maximum output, and battery capacity.

I use Square D QO panels. The largest branch breaker which has handle over one pole, so it can interlock with main breaker using their sheet metal interlocks, is 125A. They have a 200A, but handle is in middle. The Homeline series has a 200A breaker with 4 poles ganged, so I think that would interlock.

 

[Cmy]

House's two 1997 GE panels each have a 200a breaker at the top fed separately from the meter. The meter's exterior line first goes through a Square D 200a CB disconnect panel and then on to the addition's panel (hom200a) and planned inverter building. Ideally, that line could be connect to a 200a breaker in one of the two interior panels and concentrate critical loads on that panel. Ballpark $500 for a non bolt in 200a breaker and give the CTs a larger load to manage.

Square D 200 exterior CB disconnect needs to be replaced by a utility required external handle disconnect. Easiest part of the problem if only one output.

Reputable electric company but an initial suggestion was to dig part of the street line, move it and the meter panel right, and put a three out disconnect by where the current lines go. Sounded more expensive and I am trying to keep electric prep less than the solar cost.