Is this OK for a dump load?

[cyplesma]

I got a HF ad via email they are selling 100 amp 12 volt testers, my question is would this be an ok, great, or crappy dump load?

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=90636

[TomW]

cy;

Well, one thing I would not trust is the ability of that device to soak up a continuous input of any magnitude for any length of time.

I say just forget it. Buy a $20 electric "milkhouse" heater and do some minor modification and make a real load.

Just my first thoughts.

Cheers.

TomW

[asheets]

A quick search of the board indicates that some have tried using the HF unit, with mixed results.  I think the consensus might be that the carbon pile doesn't last that long.

[Tom in NH]

At the risk of raising more questions than answers, I wanted to relate a story my co-worker told me about when he used to work on the railroad. The diesel locomotives have electric motors on the wheels of the cars that turn to generators when they need to brake. The locomotive has a big iron bar that runs the length of the car, and that bar is where they dump the electricity generated by the brakes.

If you don't intend to actually use the extra electricity, why not just short the alternator output into a sufficiently sized piece of scrap metal?

--tom

[nick1234]

next time you see a electric range in the trash take the elements and use them as a dummy load you can heat your coffee on it enjoy

nick1234

[cyplesma]

I had thought about grabbing the electric elements from an electric stove, (figures why I haven't seen any of those lately), been tempted to buy some.

I would prefer to use the power and dump it into a water heater, but..... years ago we "had" to get a gas water heater, so I am reluctant to drill any holes into our current water heater and I'm not so sure I want to tempt an old water heater with electric either(not in the house anyway), don't really want to buy a new one.

I did see some 12v fans at wallymart fairly cheap but they didn't look like they would use that much power, so I probably grab a couple of those to force some air through the ducts from the cold air in crawl space for this summer's heat (save on air conditioner use)

Is there any type of resistance value of the metal or should it be a short?

[TomW]

cypl;

I am reluctant to drill any holes into our current water heater and I'm not so sure I want to tempt an old water heater with electric either

I was going to suggest an old electric unit as a "preheater" that plumbs in between the cold supply and the cold inlet on the gas unit. That way it is not your main unit and you can always bypass it if it fails.

I have other ideas, also but are to complicated to describe well in a short message.

Cheers.

TomW

[cyplesma]

yeah, I was kinda pressed to finish that post up, had a customer that needed some answers.

I have a few other ideas myself, but the trick is trying to determine what the "BEST" answer is. Kinda, like those old multiple choice questions that actually were hard to answer unlike most of the ones I see today that is just a process of elimination.

8 )

I thought about the preheater part also, just not sure if that's what I actually what to do. Of course there are those things that you know your going to do it's just a matter of finally deciding to do it.

[Ungrounded Lightning Rod]

next time you see a electric range in the trash take the elements and use them as a dummy load

For a bigger (and hotter) load drop into a truck stop and buy a 12V electric hotplate.  B-)

(But a few stove elements or oven glowbars may be more appropriately sized for dump-load steps when operated at 12, 24, or 48.  They'll also run cooler and last a very long time.)

[nick1234]

heating element hot wire range element hot water element basicly same thing nichrome wire (electric resistance wire) i sugested range element because of wattage. cut to length you need (ohms law)for desired load check elink has calculator www.resistancewires.co.uk enjoy

nick1234