I need to design custom resistances for my 5kw 3 phase Resistive load with switchable load setting, So for that purpose I need to design my own resistances that can carry around 100w to 200watts heat and can be cooled using forced air

Voltage- 440v
Phases- 3
Maximum Power 5 Kw Continuous

 

I need to design custom resistances for my 5kw 3 phase Resistive load with switchable load setting, So for that purpose I need to design my own resistances that can carry around 100w to 200watts heat and can be cooled using forced air

Voltage- 440v
Phases- 3
Maximum Power 5 Kw Continuous

How do you plan to fabricate these resistances? Have you ever worked with ceramic materials?

 

Suggest you use commercial power resistors such as this.

 

How do you plan to fabricate these resistances? Have you ever worked with ceramic materials?

I think of getting hand made if that doesn't required any special tools, I guess for ceramic I might be able to work on.

 

I think of getting hand made if that doesn't required any special tools, I guess for ceramic I might be able to work on.

I think it might require specialized tools.

 

If you have to do this by hand. Use the wire from oven heating elements for your resistor.
I have made resistor boxes with resistors like from post #3 and added fans.

I have many resistor boxes using this type of resistor. I bolt them to a heat sink using thermal glue. Use fans to keep the heat sink cool. In some cases, I drop the heat sink in a gallon of transformer oil to get the heat out of the resistor.

I have used light bulbs as loads. The old tungsten bulbs.

 

In my work I use commercially available mains load-banks, rated to 20A @ 250V (single phase) – they have the capability to adjust the load from 0-20A using switches and a 1A adjustable load. When a 3 phase load is required, three are connected together.

I would think it would be a cheaper and easier option to buy a ready-made unit that meets your needs, it would certainly be safer.

 

I have done just that, except that they were for illumination for crash testing video recording. An array of 120 volt, 1000 watt floodlights across each of the three phases of 460 volts (delta connection). A load like that is adjustable in 3000 watt steps. These were arrays of 3 by 8 1000 watt floodlights. We sold a lot of them.