My printer has two 6.8 OHM heating resistors in parallel. That circuit at 12V must be 42.35W and 3.4OHM. It has 16ga wire connecting it.
A heating cartridge is rated 12v 40W. That must be 3.6 OHM.
I wonder if the heating cartridges could handle an extra 2.35W each or if I need to add a resistor in series with them to reduce the wattage. If I have two in parallel, the circuit would draw 80W and I would be at 1.8 OHM.
Oh wait…the heater cartridges would draw less Watts. The question is, would my wiring or RAMBO die when trying to serve up 80W. It seems the fuse may have to handle 6.7A instead of the default 5A fuse if I use two heater cartridges.
Someone told me that two 12v 40w heater cartridges would have so much heater power that the RAMBO would not be able to regulate the heat well enough.
The platform heater channel needs to be able to handle 120W, and a dual extruder printer will have two of those 40W heaters (controlled by separate MOSFETS). So no, running two 40W heaters will not blow up your electronics. The 16awg wire should also be fine, though I don’t know why you would want so much heating power, and you’re unlikely to find PID settings that will keep the temperature very steady with that much power.
I may end up having to leave one hole open or keep the power low if I want good heat control, I guess. I mainly want to replace the wiring of the dual heating resistor setup because it looks so damned sloppy. I guess I am just way too picky.
This was for a single hot end btw which would put the mosfet load at 80w if I use two in parallel. I was not even thinking about the mosfet’s max wattage.