? About Generator/Solar Switch

tcvb

What is the best set up to switch between Generator/Solar.I currently run a manual 7 circuit flop over switch to my generator.I am looking at cutting a switch in line between it so i could feed it either with solar or generator.Do they make such a switch?

Thank's

Tim

Cariboocoot

Re: ? About Generator/Solar Switch

You are referring to an AC transfer switch. There are many different kinds and configurations. Which one would be right for you depends on exactly how the AC wiring goes in your application (120 VAC or 240 VAC for example), how much current is involved, and what inverter you will be using (some have built-in transfer switches).

vtmaps

Re: ? About Generator/Solar Switch

Cariboocoot wrote: »

You are referring to an AC transfer switch. There are many different kinds and configurations.

Another consideration: some transfer switches (often used on boats or RVs) manage the grounding so that when you are on generator or solar the neutral is bonded to ground, but when you are on shore (grid) power the system is unbonded so that the bond can be on the shore system.

This may be a relevant consideration for you. Where is your AC neutral grounded?

--vtMaps

tcvb

Re: ? About Generator/Solar Switch

Transfer switch grounds are tied in box,

Cariboocoot

Re: ? About Generator/Solar Switch

tcvb wrote: »

Transfer switch grounds are tied in box,

It's a tad more complex than that. At some point there is probably a Neutral to Ground bond. The location of this in respect to the other wiring makes a difference because you only want one N-G bond.

Does this application have grid power as well? If so, the N-G bond will most likely be in the main distribution panel. If there is no additional bond present either in the generator or the inverter then you can leave the neutrals and grounds connected at all times and only switch the hot(s).

tcvb

Re: ? About Generator/Solar Switch

Yes i am on grid,and i have generator bonded to main through xfer switch,plus grnd rods,i always thought that its best to tie all grnds together to keep from having a differnce in potential.

Thank's

Tim

Cariboocoot

Re: ? About Generator/Solar Switch

tcvb wrote: »

Yes i am on grid,and i have generator bonded to main through xfer switch,plus grnd rods,i always thought that its best to tie all grnds together to keep from having a differnce in potential.

Thank's

Tim

That is correct. All grounds going to a single Earth ground point is best.

The issues come up when the main service panel as a Neutral-Ground bond (as would be found in grid applications) but there is also another such bond in the generator itself and/or the inverter. Most small generators have floating neutral and thus no N-G bond. Most hard wired inverters are the same.

But some generators, especially larger ones, may have their own N-G bond. Also some inverters, most typically the ones with built-in outlets. It's one more thing that needs to be checked before you can be sure the wiring is correct.

We see this problem a lot with RV installs where the inverter has a N-G bond and then when you plug in to 'shore power' it has to be interrupted because the shore power also has its own N-G bond. As per vtMaps comment, there are transfer switches just for such situations.

But if the gen and inverter do not have the N-G bond and there is one in the main service panel then all that needs be switched is the power source 'Hot' line(s).

techntrek

Re: ? About Generator/Solar Switch

Question for the OP, do you need to switch from the inverter to the genset because you need a higher power output from the genset for certain loads, or can you run all of your loads from the inverter?

I ask for two reasons. One, when switching from one source to the other your lights will flicker and any running motors will get jolted as they transfer from one sine wave to the other. Minor, but something to consider. Second, all non-inverter-gensets have dirty output. Tube fluorescent lights, incandescents (not that you should be running any of them), halogens, all will flicker constantly. Most other appliances won't be affected.

If you can run everything from the inverter consider using it as your only direct source and then using the genset to only recharge your batteries. Even if you have an inverter-genset this will save you from buying the transfer switch.