How do you plan on powering the device? In the US, the standard 120 V outlet is only rated for 15 amps.
2640 watts 梅 120 volts = 22 amps
This is even too much for a 20 amp outlet.
Please update your question with the utilization voltage.
Here is an explanation of what happens if you connect the two in series. I will assume the two heating elements are exactly the same size.
2640 watts 梅 2 elements = 1320 watts per element.
1320 watts 梅 120 volts = 11 amps.
120 volts 梅 11 amps = 10.9 ohms
Placing the two elements in series give you 10.9 鈩?+ 10.9 鈩?= 21.8 鈩?br>
The resulting current draw is 120 volts 梅 21.9 鈩?= 5.5 amps
120 volts x 5.5 amps = 660 watts.
--------------------------------------鈥?br>
How about wiring the equipment for 3-wire, 240 volt operation. Each heating element can be operated separately at 120 volts on opposite legs of the 120/240 V service . You can operate either one or both of the elements at a time. If you need more control over the power level, you could add a 120 volt, 15 amp diode to each element with a switch that would bypass the diode. With the diode in the circuit you would basically feed the element with a half-sine wave resulting in half power. Wiring both heating elements this way gives you the following control.
0 watts = everything off
660 watts = one element with diode
1320 watts = one element full power
1980 watts = one element full power, one element with diode
2640 watts = both elements full power
Disclaimer: I'm not sure why you are trying to build this contraption, however anything you build is not UL approved and would be considered unacceptable for commercial purposes. It is very possible that you will be building yourself an unsafe appliance. Proceed with caution.A.C. load control. What is the cheapest diy heat element control.?
Just curious how much coffee you are roasting? You've likely done more roasting research than I have, but to me it seems that heating elements from two poppers is overkill, unless you are roasting a lot of coffee. People seem to get good results with a 1500 watt heat gun for 8oz of coffee.
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Dimmer switches are only 300 to 500 max.
Make a switching device to place them in series and parallel
or get a high powered reostat in series
I've used solid state relays for this type of control. Combined with a process controller it works fine and I don't remember it being that expensive. I used a Thermocouple to feed back the temperature and was able to control the temperature very tightly.
Red Lion makes the controls and relays.
On series or parallel it depends on the voltage the heating elements were designed for, and the voltage you are using. If the elements are set up for 110 volt and you are running them at 240 they need to be in series.
If they are set up for 110 volt and you are using 110 volt they need to be in parallel. Otherwise the combined resistance will cut your wattage below what you expect.
Try a dimmer switch. They are cheap
This device is basically a triac which, if you implement your own gate control will do fine.
How precisely do you need to control the heaters? If you really want cheap, you might try one of the controls used on an electric stove. If you are going to be running a new power circuit anyway, and if your heaters are identical, you might connect them in series and run them off 220-240V, that way the current would be only about 11A and you could avoid that expensive #10 wire. I think I'd use a 20A (#12 wire) 240V circuit, but since 80% * 15A * 240V is 2880W I suppose you might be able to use a 15A circuit, one would have to check the code.
as the heat element is pure resistance, the best fit would be use of a light dimmer but the required power might be problem. I found some dimmers contolling up to 2000w max.
In this case you would need two of them, controlling each heating element separatelly (but you still can adjust the same power for both). If you can not buy one, it is rather simple to builld one if you have any electrical/electronics skills.
If you want to handle the whole 2600W. off a single
control, it won't be cheap.
Your best bet would be if you could find a used or surplus variac.
If you're willing to split the load into two segments,
(and assuming you have 120V. heating elements),
there are 'off the shelf` dimmers rated 1500W. that would suit you nicely.
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