Generator Interlock, 320 service

[nsula_country]

So, having survived Hurricane Laura, I have been thinking of upgrading my generator.

We used 1 4000W/3250W propane generator for the 6 days without power. We stayed in TT (50 amp). Running only 1 AC and the house fridge. 4-6 hours a day would shut that down and move generator to the shop (Big Red Barn) to run a freezer and fridge (beer). These properties are about 300 yards apart, 2 separate services.

Propane 4000W is awesome camping and running fridges, not so much in 90*+ weather also running a 15.5k BTU or 13.5k BTU RV AC in addition to fridges.

Looking at 25-40 KW PTO or stationary diesel generator. 4000w will be used at shop for light loads and camping. No interconnecting loads.

House service is a 320 meter can feeding 2, 200 amp feed thru lug panels, with mains. They feed 2, 200 amp panels in the house. Meter pan in center and exterior feed thru panels flank each side.

Option 1
Install 400A manual SE rated xfer switch between meter and 2 exterior 200A panels. Generator feeds xfer switch AUX.

Option 2
Use manual interlock kits. Install interlock in each exterior panel.

Panel 1
Interlock between main and generator breaker. Generator feeds panel 1. A second breaker feeds panel 2.

Panel 2
Interlock between main breaker and breaker from panel 1.

As I see this, by using 2 interlock kits and panel 1 feeding panel 2, nothing can cross sources. Both panels are powered and both mains are OFF. Load shedding will be turning off breakers not needed.

POCO street light lets me know when power is restored.

INTERLOCK kit to be used on each panel.
http://www.interlockkit.com/product_p/k-6010.htm

Thoughts?

CT

 

[pattenp]

Sounds okay. Interlocks are cheaper here... https://www.geninterlock.com/

 

[nsula_country]

Thank you, pattenp! Looked at the link. They are out of stock. Price is about half. Could buy 2 interlock kits for the price of one on the other site! More cash for generator, wire and breakers.

I used 50A as an example. All 3 breakers will be whatever value required for whatever generator I install.

Made up a sketch, makes sense to me. Appears much simpler than rewiring the whole supply to incorporate a 400A double throw xfer switch.

Only 1 power source at a time on the bus.

The 50 to 50 breakers between panels is no different than feeding a non-main sub panel.

View media item 106513
CT

 

[Bert_]

I don't see a reason for the second interlock to be fed from the first. Just splice the generator feed and connect to each interlock breaker directly.

 

[nsula_country]

I don't see a reason for the second interlock to be fed from the first. Just splice the generator feed and connect to each interlock breaker directly.

Bert,

I had thought of that too. Did not know if Panel 1 feeding Panel 2 was cleaner than having parallel generator source feed.

Anyway, I have a plan now. Also, another hurricane, Beta is moving this way. Hopefully the power line repairs hold up from the last hurricane!

CT