Brucepts wrote:
For a high end flowbench bench build not sure how it will hold up?.
The SSR itself should be fine, but the heatsink will be what limits how much motor load it can handle.
If you run the bench flat out at full power for several minutes, and if you can hold your finger on the heatsink continuously, it will be fine.
Commercial heatsinks in the smaller sizes are very convenient to use, but a flat rectangular 3mm aluminium plate with the SSR bolted right in the middle works just as well.
If you need something really really big, a plain flat vertical aluminium plate will always be by far the cheapest option if you have some place to locate it.
A very rough sizing rule might be two square inches of total vertical surface area (with both sides exposed) per amp.
A flat sheet a foot square should be good up to about sixty or seventy amps.
A flat sheet six inches square maybe up to fifteen or eighteen amps.
There are many factors that can influence this, but if it runs cool enough to the touch at full power it will be o/k.
A heatsink can never be made too big.
If you are really stuck, a cooling fan may be an option, but it is one more thing that can go wrong.
Also known as the infamous "Warpspeed" on some other Forums.