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.