Re: (ET) power outages

["Steven Naugler" <snaugler earthlink net>]

Dan,
    When sizing a generator or inverter, current inrush must be considered.
It's not unusual for an AC motor to draw 5 times running current during
starting.  If a generator cannot deliver that inrush current without a
significant voltage drop for 1/2 to 2 seconds, your load may never start.
And you burn up controls.
    I had a friend that had a 4kw Coleman generator on a farm.  That
generator could not start their well for the farm house even with all other
loads removed.  (I don't know the well motor size, but it was a typical
residential sized submersible.)  I have a 3.5kw Honda that I bought at
auction and repaired.  It will start my submersible well pump motor even
when my boiler oil burner and circulator are running or vice versa, even
with 500 watts of other loads present.
    The point is that your inverter may not handle the inrush of your
furnace controls without dropping the voltage somewhat.  The Honeywell may
be more forgiving of reduced supply voltages.  GE offered a motor/generator
inverter that may be better at handling inrushes than the solid state one;
it had a higher rated current than the solid state inverter.  (I missed a
chance to get two of them several years ago because I didn't want the bad
tractor that went with them for too much money.)

Steve Naugler

-----Original Message-----
From: Daystar Energy Services <daniel laser net>
To: ET discussion list <elec-trak cosmos5 phy tufts edu>
Date: Wednesday, January 20, 1999 7:18 PM
Subject: (ET) power outages


>Last week the Mid-Atlantic got a half inch coating of ice. 150,000 of my
>closet friends lost power. Today, five days later, only a couple of
>hundred are still in the dark. Compared to the couple of weeks of no
>power last year in New England, this was small potatoes. I was one of
>the lucky ones, but my number will soon come up.
>
>With that in mind, I spent Sunday wiring a transfer switch and generator
>input to power a furnace circut and the kitchen with refridgerator. My
>ET's inverter output ran the kitchen circut like a champ. But when I
>tried the oil furnace, the control system's relay chattered like a crazy
>man. I have heard from more than one source that cheap, hardware store
>generators burnt up furnace controls left and right last year in New
>England. After much handringing, phone calls and trips to a bunch of
>HVAC supplies, I took the chance and replaced the White-Rodgers control
>with the Honeywell product. The relay clacked into place and stayed
>put.  I figure that I can run at least one circut for about a day from
>the ET alone, depending of course on how cold it is or how often we open
>the fridge. With the cheap, hardware store genterator that I already had
>to recharge the batts, maybe I can keep going. Of course, I'd have to
>unplug for a while to plow the driveway.
>
>Dan
>
>