Panel Replacement / Transfer Switch questions

[PV2EV]

I have had this SIEMENS 30/40 Generator Ready Load Center stored in my barn for years to replace the non-Generator Ready version in my house. It is intended to use this SIEMENS Automatic Transfer Switch. Would this work with Pro Power, assuming 30amp plug input?

On a related note; The GC I fired after the mistake ridden rough in of most of my house, somehow got the electrical rough in permitted although the downstairs 200A 30/40 panel was full and using 39 circuits. There is not much load on the panel (a large number of 15amp circuits), however, I am 1 circuit short to add a 100A breaker for the FCSP, even if I use quad breakers to get the space. What is the concern with having one too many circuits?

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[FlasherZ]

I have had this SIEMENS 30/40 Generator Ready Load Center stored in my barn for years to replace the non-Generator Ready version in my house. It is intended to use this SIEMENS Automatic Transfer Switch. Would this work with Pro Power, assuming 30amp plug input?

On a related note; The GC I fired after the mistake ridden rough in of most of my house, somehow got the electrical rough in permitted although the downstairs 200A 30/40 panel was full and using 39 circuits. There is not much load on the panel (a large number of 15amp circuits), however, I am 1 circuit short to add a 100A breaker for the FCSP, even if I use quad breakers to get the space. What is the concern with having one too many circuits?

As long as the breakers are listed for use with that panel and in the slots designated for use by tandem breakers, likely nothing that impacts you. Look at the diagram on the door of your panel - some limit where tandem breakers may be used, some allow them anywhere.

There are some box fill, conduit fill, etc. limitations but you're unlikely to hit them with a single tandem.

Some panels may have circuit limits, but in my experience they take into account a full box with all tandem breakers (e.g., "40 spaces, 80 circuits").

 

[PV2EV]

As long as the breakers are listed for use with that panel and in the slots designated for use by tandem breakers, likely nothing that impacts you. Look at the diagram on the door of your panel - some limit where tandem breakers may be used, some allow them anywhere.

There are some box fill, conduit fill, etc. limitations but you're unlikely to hit them with a single tandem.

Some panels may have circuit limits, but in my experience they take into account a full box with all tandem breakers (e.g., "40 spaces, 80 circuits").

Thanks. Bottom right of attached sticker indicates why only 40 circuits and not 60, damn!

Any idea if there transfer switch solution would work with ProPower like the Generac version often mentioned here?

 

[FlasherZ]

I have had this SIEMENS 30/40 Generator Ready Load Center stored in my barn for years to replace the non-Generator Ready version in my house. It is intended to use this SIEMENS Automatic Transfer Switch. Would this work with Pro Power, assuming 30amp plug input?

It does not appear that the Siemens Transfer Switch or the GR load center allows for switched neutral, which is required when using a generator (like the F-150 Lightning) that has bonded neutral / ground. The bonding required for the grid in your main panel creates a ground loop that will trip the truck's GFI protection.

You will probably need a separate transfer switch (including switching the neutral) that is designed for GFI-protected generators.

 

[PV2EV]

It does not appear that the Siemens Transfer Switch or the GR load center allows for switched neutral, which is required when using a generator (like the F-150 Lightning) that has bonded neutral / ground. The bonding required for the grid in your main panel creates a ground loop that will trip the truck's GFI protection.

You will probably need a separate transfer switch (including switching the neutral) that is designed for GFI-protected generators.

Thanks, that was the concern. In somewhat of a followup thread, I asked: With 30A working for the Lightning, does it make sense to oversize a Manual Transfer Switch (say 50A) for a future proof install? If so, what do I do for the outlet/truck connection?

Also I am assuming I need to transfer both 120v circuits that share a neutral (stupid 3 wire job on my house)?

 

[FlasherZ]

Thanks, that was the concern. In somewhat of a followup thread, I asked: With 30A working for the Lightning, does it make sense to oversize a Manual Transfer Switch (say 50A) for a future proof install? If so, what do I do for the outlet/truck connection?

Also I am assuming I need to transfer both 120v circuits that share a neutral (stupid 3 wire job on my house)?

That involves a number of variables. From a portable generator standpoint, 30A is approaching the top of the range at 7.2 kW. So if you want a bit of investment protection, the next step up is whole-house, and so you'll have to figure how large of a generator you'll need (10 / 15 / 25 / 30 kW or larger). My home is protected by a 25 kW genset and I use a full 200A service-rated ATS (Generac's is $550-700 or so).

Those 3-wire circuits are called multi-wire branch circuits. They're not so bad where you have multiple circuits running to a single place. They save on wire, because you only need one neutral for 2 circuits, with the neutral carrying only the imbalance between the two circuits. However, since code requires that both circuits be disconnected simultaneously, you'll have to relocate them both.

 

[Crilly]

You could disconnect one of the 15 amp circuits. Or double one up that you know they well not be over 15 amps combined.

 

[FlasherZ]

You could disconnect one of the 15 amp circuits. Or double one up that you know they well not be over 15 amps combined.

MWBCs use a shared neutral, and both ungrounded legs must be moved so that the neutral won't be overloaded.

 

[mmcguirk]

You will probably need a separate transfer switch (including switching the neutral) that is designed for GFI-protected generators.

Any product recommendations for this transfer switch? I already have a subpanel with all my "essential" loads that has a mechanical switch so I would like to avoid the big bucks for one of those Generac HomeLink boxes that I have seen recommended elsewhere. Thanks.

 

[PV2EV]

The PV system you have makes all of this much easier to decide because you have the ability to recharge your portable battery bank. If you take simple steps now you can more or less eliminate even having to worry about whole system backup to begin with.
[/QUOTE]
My well pump, fridge, freezer, lights, Uponor climate control system w/pumps (radiant heat on propane when grid down), condensation pump and HRV are getting close to 30A, but it should be enough.

If the outage is short then I can recharge after, but when long, PV is down so useless. The reason I want a whole house solution is to use PV during the day (including EVSE & DHP/AC) and the truck battery at night in a long outage. Someone will do this, but it may be a while, and might not support the Lightning.

In the interim I will install the Generac 6854 30A transfer switch using the conduit I ran for the HIS/FCSP DC wires.

 

[ericpullen]

For all of us doing manual transfer switches or interlocks, make sure to account for in rush and not flip all the breakers on at the same time.

 

[PV2EV]

For all of us doing manual transfer switches or interlocks, make sure to account for in rush and not flip all the breakers on at the same time.

The ciritcal loads are on by default. So once down, switch some off before transferring power?

 

[ericpullen]

I’ve had a interlock with regular generator for a bit now, and I feel the safest way is to just turn everything off (all breakers) except one with a light near you and then kick on the generator breaker. Make sure all is well, then flip one one at a time, waiting a min of 45 seconds between each flip. If you know it is a pump of some sort (like an ejector pump), might be good to let it run through one full pump before moving on.

My $0.02, I’d rather be cautious when starting loads.

 

[PV2EV]

Oh, this is SOP for all solar PV. My excess PV power is fed to the grid, without which I would have no were to put that power (dump load). Part of what most battery management system (BMS) do for solar is create a microgrid, treating the battery like a dump load, allowing the inverter(s) to keep the solar on and inveerting that power to AC. The HIS from Ford/Delta DOES?NOT?DO?THIS as the Bi-directional Inverter (BDI) of the HIS has no AC out, making the name untrue.

So the BDI definitely has AC out, where you are getting that it doesnt have that is confusing. Also you already have a DC to AC inverter which means that even if the grid went down you could feed regulated AC power into the FCSP to charge the truck with 15 kW and 9 kW to the house. This is also accomplished by the HIS albeit in an easier way.
[/QUOTE]
SunRun and the reseller of the HIS have said the PV goes down when grid down, and I don't see an AC out of the BDI (see below). Also below, the FCSP is on the main

panel, not the MID/CL panel.

 

[PV2EV]

Also you already have a DC to AC inverter which means that even if the grid went down you could feed regulated AC power into the FCSP to charge the truck with 15 kW and 9 kW to the house. This is also accomplished by the HIS albeit in an easier way.

My inverters shut off when the grid goes down as described prior.

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