[Elecraft] OT: Whole House Generator - Update

[Mark Stennett]

Don’t forget break before make transfer switches. These provide for complete disconnect from one feed for a brief period before connecting to the other.


73 de na6m



On 9/9/17, 2:02 PM, "Dr. William J. Schmidt" <elecraft-bounces at mailman.qth.net on behalf of bill at wjschmidt.com> wrote:

    Well there can be a little more to it. With the larger systems there is phasing circuitry (in the generator or the transfer switch:  i have both) to detect and switch at zero cross-over point for "bumpless" transfer of power.  Causes the least amount of surge and damage. 
    
    
    Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ
     
    Owner - Operator
    Big Signal Ranch – K9ZC
    Staunton, Illinois
     
    Owner – Operator
    Villa Grand Piton - J68HZ
    Soufriere, St. Lucia W.I.
    Rent it: www.VillaGrandPiton.com
    
    email:  bill at wjschmidt.com
     
    
    > On Sep 9, 2017, at 2:36 PM, Charlie T, K3ICH <pincon at erols.com> wrote:
    > 
    > It's Generac "Synergy" not syntergy
    > And yes, they just came out with them as their own version of the inverter
    > type generator.
    > I've only seen it listed on a few of their dealers so far.
    > 
    > There's nothing magic about wiring a transfer switch. In the larger systems
    > of about 7 - 8 kW and higher, think of it as a remote sub-panel that might
    > for example, be in a garage and fed out of your main house panel through an
    > appropriate sized breaker, but with a two way switch for the Line In that
    > selects either the line from the main panel or, the generator.
    > This applies whether it is manually operated or fully automatic.
    > All the control switching logic comes from the manufacturers circuitry.
    > 
    > The whole idea is to NEVER permit your generator output finding its way out
    > to your main feeders. (You could electrocute a Lineman working on what he
    > thinks is a dead line.  That pole-pig outside works both ways.  You apply
    > 240 V on your side and there is 7½ or higher kV on that deadly wire!)
    > Unless there is a massive failure in the switch itself, this can never
    > happen.  Most of the ones I've seen are WAY overrated for just that sort of
    > safety margin.  My panel came with a 15 kW generator, but has a 200 Amp
    > transfer switch.  The commercial power input is completely dis-connected
    > from the generator much the same way as a DPDT switch's outer contacts never
    > touch.
    > 
    > In some of the smaller transfer panels, each house circuit has its own two
    > way switch such that you have to manually switch it from mains to generator
    > and back when the juice comes back on.  This works fine too and isolates the
    > generator output.
    > 
    > 73, Charlie k3ICH
    > 
    > -----Original Message-----
    > From: elecraft-bounces at mailman.qth.net
    > [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Doug Hensley
    > Sent: Saturday, September 09, 2017 1:44 PM
    > To: Elecraft List <elecraft at mailman.qth.net>
    > Subject: [Elecraft] OT: Whole House Generator - Update
    > 
    > Someone on the list suggested we post a summary of private responses to us
    > as an alternative, I'm guessing, to members not knowing what was said.   In
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