what happens if I use for dumpload a coffemachine?

[Henry Jobeh]

Hi everyone,

I have a stupid question. With a small dumpload, can this be used?
I seen someone online use a toaster just the wires of it connected to dumpload.
I have a cofee machine that has a hotplate. It works on 220V Ac. Now if say 12V is applied to it then it should get at most lukewarm. If you half the current then one quarter of wattage. I can produce 4W. A tiny bit more I think than cofee machine can handle. It is a 900W cofee device. If I use this cofee machine pure as dumpload, do I need to rewire anything? If the battery is full and it all goes to the dumpload, read cofee machine, then is ok? It has an overheating switch but I do not see how it would ever get too hot to trigger it.

What needs to be done to use this device pure as dumpload? I can use the warmth to keep a store room dry.

[Rob Beckers]

Hi Henry,

Welcome aboard!

Assuming this is a 'dumb' coffee maker, where the plate heater is always on (with a thermostat, but that will never kick in), then yes, it should work. The Wattage will be very, very small though: Wattage goes with the square of the Voltage if the resistance stays the same, so you'll get (12/220)^2 = 0.003 x 900 = 2.7 Watt out of that. It may not even get lukewarm.

Now, wire resistance actually goes up as the temperature rises, so that 900W is at working temp, and the resistance when cold is a little lower, so you likely get a little bit more than 2.7 Watt into that dump load. Just measure the actual resistance with an Ohm meter when cold to get an exact number. Wattage equals Voltage squared divided by the resistance.

-RoB-

[Henry Jobeh]

Is it that easy? Wow Thanks for your very fast answer. I will connect it. :bigsmile:
Yes it is a cheapy dumb one. I perhaps should just use the plate and rewire it with bigger wires?
I took a look inside and see only a big round element and surprising very thin wires to it from the on/off switch.

[Rob Beckers]

Only the finest of Chinese engineering... :weird:

If they can save half a penny by making that wire thinner and still comply with code they'll absolutely do it!

-RoB-