[RE-wrenches] automatic transfer switches

[Chris Mason]

If you are doing it on the AC side, a Generac transfer switch has the
capability and is designed to do this. It's easy to rig an interface as I
discussed privately with Bill.

On Fri, Nov 29, 2019 at 1:29 AM Jerry Shafer <jerrysgarage01 at gmail.com>
wrote:

> Wrenches
> Need to be careful here to use something that has the interrupt KVA rating
> required to prevent an arc in the event of an under load opening with the
> switch proper AIC rating 10,000 or more, last thing I think you want is to
> have that kind of liability on products that are not designed for that type
> of use. But thats just me.
> NABCEP PV Inspector
> California Solar contractor
> Jerry
>
> On Mon, Nov 25, 2019 at 8:52 PM Bill Hennessy <bill at berkssolar.com> wrote:
>
>> hi folks--
>>
>> We're installing a grid-tied, battery backup system on a farm where the
>> service entrance is on a pole in the yard. At the single-phase, 240v,
>> service entrance, there are two main breaker subpanels--one going to the
>> house and one to the barn. The buildings are each about 100 feet away from
>> the pole in opposite directions. The PV/battery system is located in the
>> barn. When utility power is lost and the battery backup kicks in, we are
>> looking for a way to bypass the house subpanel at the pole so it won't
>> backfeed the grid.
>>
>> When the grid drops out, we need to tie the backup power coming from the
>> barn to the line going to the house. We're thinking an automatic transfer
>> switch installed at the pole will do the job, but the transfer switches
>> seem to have built in delays to work with starting a generator. The
>> switch does not have to be service entrance rated.
>>
>> It looks like the Asco 300 series has time delay adjustments, but it is
>> pricey and has a seven-week lead time. (Thank-you PG&E)
>>
>> The battery backup system will switch over in milliseconds and we were
>> hoping to find something similar for the transfer operation at the pole.  We're
>> looking for something simple--hopefully a basic transfer switch that will
>> quickly switch and drop out when grid power is restored.
>>
>> Would appreciate any thoughts or suggestions.
>>
>> regards, bill
>>
>> Bill Hennessy
>> Berks Solar, LLC
>> 371 Centennial Rd
>> Mertztown, PA 19539
>>
>> o 610 682 4300
>> c 484 560 4666
>> NABCEP certified installer
>> PA contractor #44411
>> www.berkssolar.com
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-- 
Chris Mason
Solar systems designer
Generac Generators Industrial technician

Comet Systems Ltd DBA Comet Solar
Anguilla Cell  264.235.5670
WhatsApp 264.235.5670
Skype: netconcepts
www.cometsolar.com <http://www.cometenergysystems.com/>
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