Dump load theory question

[Roger Clement]

Originally Posted by guyrj33

if your dump resistor is .15 ohms it will take 100amps to create 15v across the resistor.
V= Rxi
15volts = .15ohms x 100amps

would it make more sense to size the resistor to see 15v across it when the source output is approaching it's maximum?

Each resistor is rated for 15v.. That's about the voltage level it will start dumping to it. I rated it alot higher wattage to give me room in case of system upgrades. It should (if I am correct) keep the turbine spinning slowly by being loaded up by the resistance load. I'm not sure if a really strong wind will make it spin fast while cut over to the dump load. �� Thanks to all who have been a great help for the benefit of this technology. ��. Great people here I see.

[joelhemington]

Originally Posted by Roger Clement

I've proceeded to attempt to build my own dump load resistor from an oven element. Is there anyone who can check and confirm my math? ��

Oven element
230v 3500w 15 ohms. 50" total length.

To convert to a 15v 1500w dump load resistor :
Volts squared / resistance = Watts

15 ohms / 50" = .3 ohms per inch
.3 ohms x 5 = 5" for 1.5 ohms each.
5" sections x 10 = 1500w @ 15v
.15 ohms total in parallel

15v x 15v /.15 ohms = 1500 watts

I'm probably missing something here (it's been known to happen ) but why not just add in some additional batteries to absorb your additional power?

[Roger Clement]

Even extra batteries would eventually reach full charge. Which would in turn require the necessity to dump the excess power to another load to prevent premature battery failure from excessive charging. Unless you have other things that could utilize the excess power, the dump load resistor is a viable solution.

[GordMay]

An electric water heater element makes a cheap & effective dump load.
"Using low-voltage water heating elements as a diversion load"
➥ https://www.cruisersforum.com/forums...-198159-2.html
➥ Divert Load FAQ – svHotWire

[dmalcol1]

Not going to comment on your dump load bank.

Our off grid home has 1k 48v wind genny that is shut down at 58volts this is achieved by dry contact output signal from inverter.
Shut down is acheaved by shorting the three line wires from the genny counter EMF act's as brake. Also reduces total run time wear and tear.
It has been found that some form of time delay will be required to prevent what is referred to as hunting or hysteresis.