SW4024 switching issue [RE-wrenches]

[Kirk Herander, VT Solar]

According to the latest v 4.01 manual, the generator turn-off delay will occur
if the inverter automatically turns off the generator, OR if you manually turn
off the generator from the generator menu. In either case, the auto gen logic is
being used to stop the generator, and the delay between transfer and genny
turn-off should be there, if things are working as advertised. The delay is not
there in any SW I've installed when the generator is manually turned off by
moving the cursor to the "off" position on the generator menu(I certainly hope
my memory is correct on this one). I've never been in front of an inverter when
the stop signal is automatically initiated, but from what you described, the
delay is there, and from what I've witnessed, not when initiated from the
generator menu.

Kirk

William Miller wrote:

> Pals:
>
> At 09:15 AM 2/7/01 -0800, you wrote:
> >Kurt:
> >
> >Transfer &
> >genny shutoff occur simulateously on every inverter I've installed w/ 4.01.
> >Conclusion: vaporware. Maybe it's in 4.1. - but I'm probably dreaming.
> >Kirk
> >
>
> It has been my consistent experience that an SW inverter (V4.01)
> controlling a generator, when in automatic mode will transfer away from the
> generator some time prior to stopping the generator (40 seconds sounds
> about right).  Now, if you have two inverters stacked, the second inverter
> does not act this way.  The inverter not controlling the generator does not
> know the generator is about ready to be stopped so it does not transfer
> prior to generator stop.  Watch the green AC2 in LEDs while this cycle is
> happening and you will see the SW controlling the generator will begin to
> flash after the load is transferred away from the generator while the LED
> on the other SW remains solid.  The flashing indicates the generator is in
> cool down.  Could it be that the appliances that are resetting are powered
> by the non-generator-controlling inverter?
>
> The Trace manual claims the SW inverters (and I believe DR series, for that
> matter) can transfer power quickly enough to be classified as UPS units.
> This is complete Hogwash.  Anyone can see the lights flicker during
> transfer and during load level changes.  A small inverter system such as
> these does not have the inertia required to maintain proper voltage
> regulation for running micro-processor based appliances.  I tell all of my
> clients that having a battery powered inverter system does not mean you
> don't need a UPS, it just means you need a smaller one (less batteries for
> less required backup time).
>
> I have a client who is a glass blower.  He has an AC powered solenoid that
> will shut off his furnace in the case of a power outage.  This is necessary
> because a blower is required to operate while the furnace is running.  His
> SW system would not hold the solenoid during transfer.  I installed a UPS.
> It would not hold the solenoid (this bugger is fast!).  We invented a
> system to resolve the problem, but this underscores the fact that a SW
> system does inevitably have transfer switching artifacts.
>
> William
>

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