Offgrid Genset Transfer switch

[sodamo]

We have been totally offgrid since 2005. Several systems, several upgrades.
Our current house system is pretty robust:
Totally off grid - Hamakua side, Big Island, Hi

36 Trina 280w & 16 Phono 250w in 48 volt array (fixed) 14080w
12 Hyundai 365w (4380) 18460w total
Radian Inverters GG8048A/GS4048A w GSLCs
4 FM 80 charge controllers
Hub 10.3
FNDC w/3 shunts
Mate 3s
OpticsRE - MMKL - Ninole Hi
15 SimpliPhi 3.8 (57kw) (1125 AH)
14Kw Kohler 14RESA (Propane)
Autostrart

Charging Only
2FX3048T Inverters (no ac output)
Hub 10.3
FNDC. - shared shunt feeds from Radian FNDC
Mate 3s
EG4 Chargeverter
10Kw MEP 803a Military gen (diesel)
Honda EU7000i (gas)
Autostart

Starlink w Eero Pro 6e network for OpticsRE

My upgrades have not been kept up todate as far as geneset transfer switching
I hope to rectify that and document a bit in this thread if anyone cares to follow and/or comment.

 

[sodamo]

I have a starting design for my new transfer switch.
Goal is to run 1 or 2 gensets from either system.
Yes, I can do so now requires manual control and rewiring of autostart. Goal is the select via switches. Each system. Controls when it runs according to either battery voltage, State of Charge, or Manual -that won’t change other than possibly tweaking settings.

These items on order:

Amazon.com

Amazon.com

Above item are comparable but couldn’t decide so getting both.

Amazon.com

Amazon.com

Amazon.com

Configuration:

 

[sodamo]

While I have received some of the items, not enough for placement. Does look like all will nicely. Still missing Nilight switches and FX breaker box.

 

[Kyle_in_Tex]

Watching!

 

[WinterDeere]

Tangent: For those of you guys running multiple gensets, how do you syncronize them before switching both online? I imagine that just letting the two run side by side with a voltmeter between them might leave the opportunity for differential voltage to drop to zero every once in awhile, due to slight differences in operating RPM, and that you could close a switch between them at that time to lock them in. Once switched together, they should stay in phase.

If one is substantially bigger than the other, I'd guess this could work well, the smaller one will follow. If similarly-sized, I see an opportunity for oscillation.

 

[part-time-Farmer-NC]

WOW. Fascinating topic. I think about an off grid solution from time to time but where I am I don't have the reason to pursue it. One day thought...

Also see you are from my birth state, former military brat. Ft Tripler. We lived there the first 3-4 yrs of life for me and my little sister.

 

[90cummins]

I think we will be learning something here.
I’ll be watching!

90cummins

 

[sodamo]

Tangent: For those of you guys running multiple gensets, how do you syncronize them before switching both online? I imagine that just letting the two run side by side with a voltmeter between them might leave the opportunity for differential voltage to drop to zero every once in awhile, due to slight differences in operating RPM, and that you could close a switch between them at that time to lock them in. Once switched together, they should stay in phase.

If one is substantially bigger than the other, I'd guess this could work well, the smaller one will follow. If similarly-sized, I see an opportunity for oscillation.

Fear not.
I don’t. Have 2 generators powering same charger would be a problem I suspect and will be managed via the transfer breakers- on/off, off/on.
The generators power a DC charge source. My offgrid power is designed to accept multiple DC charging. Think solar powered charge controllers running same time as generator powered DC chargers. Technically I could run my 3 charging sources simultaneously, but I’d have to be mindful from battery standpoint.

I think we will be learning something here.
I’ll be watching!

90cummins

Me too.

Actually I do have 1 issued not resolved. Relays always puzzling to me. My current setup has each generator wired to it’s own relay and everything switched manually. I have a DPDT relay pictured, but not sure if that will work. Will be playing with configuration once I receive the switches.

 

[sodamo]

I was stationed on Oahu 77-81. Wife and I moved here in 2005. Don’t expect to need to pack for next move, simply scatchermy ashes in the dog cemetery.

 

[WinterDeere]

Fear not.
I don’t. Have 2 generators powering same charger would be a problem I suspect and will be managed via the transfer breakers- on/off, off/on.

Cool. I do believe it would be possible to link two generators, heck this is what my FIL spent his career on, as GM of a few power plants. It requires synchronization before switching them together, and probably careful management arrangement of which of the pair controls the system speed, as two governors with similar time constants on similarly-sized generators are almost sure to oscillate against each other.

Long story short, I think it's very do-able, but maybe not worth the time and complexity for any home-based system.