dump load question

[sunbelt57]

The controller I bought calls for a 1.2 ohm 600W dump load to be connected at all times. Can I use a higher wattage or higher ohms dump load?

http://www.ebay.com/itm/360356221392?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

[JW]

Can I use a higher wattage or higher ohms dump load?

The resistance would have to be less than 1.2 Ω to get higher wattage or higher input voltage to the same resistance, to get more watts.


JW

[Flux]

You can use a higher wattage resistor, it will just run cooler. The 1.2 ohms will have been chosen for the expected load. If you use a higher value it will dump less so everything depends on your power sources, if you have little solar and poor wind you may be ok with higher resistance but I would stick to the suggested figure.

Don't use a lower resistor as it may exceed the controller current rating.  The 1.2 ohm seems to be based on 24v operation but the listing mentions 12v. If it is used at 12v then you probably could use less than 1.2 ohms and if you stick with 1.2 then a 200W resistor will be enough but you ought to contact the manufacturer for any changes from the suggested values.

Flux

[OperaHouse]

Using ten 12 ohm resistors in parallel would be a better solution.  The item would be more commom and failure of one resistor would not be disasterous.  Search ebay 15 or 20 ohm resistors.

[sunbelt57]

http://www.ebay.com/itm/Ohmite-TAP600K10R-Resistors-600W-10-Ohm-10-/261045603932?_trksid=p5197.m1992&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D14%26meid%3D970435798855353033%26pid%3D100015%26prg%3D1006%26rk%3D2%26

Here's a 10Ohm 600watt. I wonder if I could use 2 of 'em in parallel.

I'm having a hard time finding anything less than $100. I did find a link on how to make your own out of stove elements on backshed.com

[ghurd]

Two parallel 10 ohm 600W is not a smart option.
It results in only 5 ohms, dumping 2.9A, or 41.5W in 1200W of resistor.
Could do the same thing with a 5 ohm 50W resistor.
G-