Connecting extruder heaters
The extruder heater connectors vary with the Duet version.
Duet 2 (WiFi and Ethernet)
A 2-pin 3.5mm terminal block is provided for connecting each of the two supported hot end heaters.
The design is rated to 5A per extruder heater connection
A 2-pin 2.54mm terminal block is provided for connecting each of the two supported hot end heaters.
The Duet 0.6 provides a 4-way Molex connector for the hot end heater. Pins 1 and 2 are connected together, so are pins 3 and 4. This is to allow the hot end heater current to be shared between the two pins in each pair. If you are using a 12V hot end heater of more than 25W power, we strongly recommend that you connect each of the hot end heater wires to both pins in its pair, to avoid overloading a single pin. With a 24V hot end heater of up to 50W, you need only use one pin in each pair.
Early Duet 0.6 boards did not use Molex connectors but instead had a 6-pin header, of which the two nearest the edge of the board were for the hot end thermistor and the remaining four were for the heater.
Caution! If you use a 4-pin Dupont-style header shell instead of Molex, and you accidentally plug it on to the pins shifted by one position left of right, you are likely to cause irreparable damage to the Duet.