The Daring Dufas wrote:

Pete C. wrote:
The Daring Dufas wrote:
Pete C. wrote:
The Daring Dufas wrote:
Ron Hardin wrote:
Is there a power-strip like device for use with portable
generators that turns off outlets when other outlets are using
a certain number of watts?

Like you'd want to turn off the refrigerator while the sump pump
cycles, to keep the total watts under say 2000; but mostly the
refrigerator stays on.

You can easily build your own if you're handy
with electrical modules. You won't have to
build any circuit boards because the parts
are available off the shelf. You can use a
current sensor and relay module manufactured
by Functional Devices, Inc which are sold at
many HVAC supply houses like Johnstone Supply.

http://www.functionaldevices.com/

http://tinyurl.com/5fuhg8

http://www.johnstonesupply.com/corp/Default.aspx

TDD
Generator load management is a bit more complicated than that and
simply dropping lower priority loads when higher priority ones
come on won't work properly and could potentially damage items.

A proper load management setup needs a controller with some
smarts, and monitoring connections to things like sump pump
switches, thermostats, etc. so that it can tell when an item
needs to run, even though it is not currently powered. This type
of control just isn't practical on a small scale where the cost
of the control would exceed the cost of a larger generator.
2,000 freaking watts! Geez! A very simple automatic switch
can do the trick for the guy. A current sensor, a timer
and a relay could make up a simple load control for the
man's generator to drop the refrigerator when the sump
pump kicks in. No micro-controller or fancy PLC needed.
If it involved 10,000 to 150,000 watts or more, I could
understand the need for more finesse. For a generator I
can pick up with one hand, nope, nope, nope.

TDD

Bull.

With a generator as small as 2KW, the generator will probably stall
before you can shed the new load, and even if it doesn't it will bog
down badly causing low voltage and low frequency issues. If it's an
inverter based unit like an EU2000i it will just go into protect
mode and you will loose output until you manually stop and restart
the generator.

You think it sounds simple, but you've clearly never done load
management, nor have you thought through the details of the problem.
With a generator that small, the OPs safest and simplest solution
is to swap power cords around manually.

Relay logic as you noted in another post would be a bloody mess for
this since you have to know the load of each of the controlled
outputs and determine the allowable combinations that will not
overload the generator.

Good Lord, you're making it more complicated than
it needs to be. I could do it quite simply with
all off the shelf inexpensive timers and relays.
I have had a smidgen of experience with little
Cats and tiny little 16 cylinder EMD generators
putting out a minuscule 4,160 volts and enough
current to melt the proverbial crowbar. Don't over
engineer the golly gosh darn thingy itty bitty
generator, it's not an APU on the space shuttle.
I guess all those 5 to 40kw generators I've installed
and maintained for homes and business have left me
with a substantial dearth of knowledge when it comes
to electrical systems. Should I walk you through
the simple steps that would address all your dire
concerns for blowing up the itty bitty power plant?
Of course, the simplest thing is as you say is to
switch cords but if he's anything like all of us
lazy humans who love to take advantage of existing
technology for the sake of convenience, he wants
something automatic.

TDD

Whoop-dee-doo, you still haven't covered the actual issues,
particularly with the probability of an inverter based generator give
the OPs mention of 2KW, and the fact that as soon as the new load
came online the inverter would trip out on overload before your relay
could shed other loads.

Prove it. Then show how simple, IF you manage to prove it, that it can
be overcome. You know not of which you speak. This has turned into a
troll fest.