How to Wire Six 380V Cartridge Heaters?

A Delta (Δ) connection should be utilized if the cartridge heaters are rated for 380 volts. To do this, you need to connect the three heaters end-to-end to make a closed triangle (delta). The three phase wires (L1, L2, and L3) should be attached to the three corners of the triangle.

A Star (Y or Wye) connection is utilized if the cartridge heaters are rated for 220 volts. This means connecting one terminal from each of the three heaters to make a common neutral point (which might be grounded) and connecting the three phase wires to the other terminals of the heaters.


When wiring six 380V cartridge heaters, they are usually set up as two separate Delta groups that are connected in parallel to the three-phase supply. Our technical team has put together a detailed wiring guide:

One frequent and useful way to connect three heaters is to utilize an Internal Star within Delta configuration. In this setup, one side of the three heaters is shorted together inside the heater (the common point), while the other side of each heater is linked to a phase wire. This makes two sets of six heaters, which are then linked in parallel to the three-phase lines.

Step-by-Step Wiring Instructions for Six 380V Cartridge Heaters:

Take off the cover or access panel of the heating assembly or connecting box.

Find the wire terminals. There will be terminals for six live/phase connections (two heaters per phase) and terminals for grounding the equipment.

Use the right equipment, like crimping pliers, to connect terminal connectors to the ends of the supply and connecting wires.

Link the phase wires. For a normal two-delta-group setup:

Put the six heaters into two groups of three.

For each set, connect the three heaters in a Delta pattern: Connect the end of Heater A to the start of Heater B, the end of Heater B to the start of Heater C, and the end of Heater C back to the start of Heater A.

Connect the three phase lines (L1, L2, and L3) to the three connections in the first Delta group.

At the same time, connect the same three phase lines (L1, L2, L3) to the right junctions in the second Delta group.

Make sure that all of the electrical connections are tight and safe according to the torque levels given.

To finish the installation, make sure the protecting earth (ground) wire is properly connected to the right grounding terminal on the assembly.



Important: The previous description that said "six live wires and two neutral wires" is not common for a standard three-phase 380V heater circuit. For pure resistive loads like cartridge heaters, a neutral wire is usually not needed or employed in a balanced three-phase Delta design. The equipment grounding wire is the main safety link. Make sure that your power source is a 3-phase 380V system and not a single-phase system with a neutral. If the voltage is not right, the heater will not work right or will break down. Also, be sure that the wiring is set up to evenly distribute the load across all three phases and that the circuit protection (such fuses and circuit breakers) is the right size for the total amperage of all six heaters. Always use the wiring diagram that came with the heaters or the machine's electrical schematic to make sure you are wiring things correctly and safely. It is highly suggested that you hire a trained electrician to install it.