PTS Flowbench Forum

As I´m putting together the parts for my build, I realize that the SSR from PTS appears to be a 1-p. Now, the power supply in Denmark is 230v 3-phase and neutral. -So, in order to avoid having to buy 3x 1 phase 240-75A SSR´s it would take up less room in the cabinet if I could find a 3phase 240v50A (or 75A) instead. Otherwise, I guess that I would need to go with 3X 1phase SSR´s with individual circuit boards and transformers. It could work, but likely more expensive and surely more space-consuming...

Anyone who knows where to purchase an SSR with 3phases and a phase control angle module? I have 32A so a 240v-50A would suffice.

/Thomas

Contact Bruce here at the Forum.

You will need three separate phase controllers, and three random fire solid state relays. The same dc control voltage will go to all three controllers so they operate together.
It gets expensive for three, but there is no way around that for three phase operation.

Bruce bulk buys these, and can probably get them cheaper than you can.

http://www.flowbenchtech.com/ssr.html

Tony wrote:Contact Bruce here at the Forum.

You will need three separate phase controllers, and three random fire solid state relays. The same dc control voltage will go to all three controllers so they operate together.
It gets expensive for three, but there is no way around that for three phase operation.

Bruce bulk buys these, and can probably get them cheaper than you can.

http://www.flowbenchtech.com/ssr.html

Thank you for shedding light on the matter Tony. It is much appreciated! -I will ask Bruce to put it on the parts list

Just out of curiosity. Why wouldn´t a three-phase controller with dc input work? -I´m not sure that I understand what difference it would make, as long as the motors receive the same dc signal.

There used to be three phase control modules such as the Semikron SKPC600 available at horrendous cost, but they went out of production a very long time ago.
Still available though as new old stock for repairing ancient equipment, if you are really desperate. (minimum order four for 1,040 US dollars).

If you click on the data sheet, you will see this is now thirty year old technology.
https://shop.semikron.com/en/Products-a ... -MK-2.html
As far as I know there is nothing more recent available, they were just far too expensive and a commercial failure.
Its no longer even listed in my old 1999 Semikron data book.

I suppose there is now a very limited market for that type of thing, since the Chinese are making single phase controllers at a fraction of the cost.

That is only the controller too, you still need three random fire solid state relays, which are also far cheaper than three of the Semikron thyristor modules which you would also need with an SKPC600.

Its going to be a bit spendy any way you go about it.
But the simplest most readily available and lowest cost solution is still going to be three single phase controllers simply because of cost reduction through mass production.

Tony wrote:Contact Bruce here at the Forum.

You will need three separate phase controllers, and three random fire solid state relays. The same dc control voltage will go to all three controllers so they operate together.
It gets expensive for three, but there is no way around that for three phase operation.

Bruce bulk buys these, and can probably get them cheaper than you can.

http://www.flowbenchtech.com/ssr.html

Hi Tony,

I was actually considering installing the attached hardware. The way I see it, it ought to work... Do you see it differently?

That is not a proportional variable voltage phase controller, but simply a three phase on off switch, otherwise known as a solid state relay.
Sorry but that is not going to work for you to control motor speed. It turns all of the motors either on or off and nothing in between.

https://au.rs-online.com/web/p/solid-st ... s/1025555/