New build with recycled parts on a ridiculous budget 120cm*60cm work area

[Desertboy]

Right I'll get 1 of these mcb's tomorrow to wire the PSU through
https://www.toolstation.com/shop/p26107

and 2 10 amp ones, one for the spindle and one for the twin 3 pin wall sockets.

I am going to wire 32amp to the junction box soon so might as well plan for the future.

[Clive S]

Right I'll get 1 of these mcb's tomorrow to wire the PSU through
https://www.toolstation.com/shop/p26107

and 2 10 amp ones, one for the spindle and one for the twin 3 pin wall sockets.

I am going to wire 32amp to the junction box soon so might as well plan for the future.

I think you might want a D rated one with that big transformer

[Neale]

I think I use a C type MCB - more surge-resistant than a B (the usual domestic type) but trips a little more easily than a D. But that's with a 650VA transformer. However, without analysing in too much detail, I doubt that the transformer difference is that significant and it's the size of the capacitors that matters more. I would tend to go with C type, I think.

[Davek0974]

Just an observation - are you running the primaries in series (240v) or parallel (115v) ??

If series the you need to connect supply to blue and brown with grey/violet joined.

If parallel then connect blue/violet and grey/brown then connect supply to to those pairs.

Just an observation as said but easy to ignore those little dots on the transformer winding pictures ;)

[Desertboy]

Just an observation - are you running the primaries in series (240v) or parallel (115v) ??

If series the you need to connect supply to blue and brown with grey/violet joined.

If parallel then connect blue/violet and grey/brown then connect supply to to those pairs.

Just an observation as said but easy to ignore those little dots on the transformer winding pictures ;)

I had it wired blue and brown to mains 240v, grey and violet joined on the input side. On the output side orange and red to the rectifier, yellow and black joined. This was a dual 25v output core.

This time with the 1kva transformer I'm going to wire the input the same (it's a dual core 115v input). The output I will join the orange and black and then wire to rectifier, join the yellow and red and to rectifier. (Dual core 50v output, I want 50v out to feed into the rectifier so I get my 68-70v out for my drivers.)

[Desertboy]

If I add a precharge circuit to this, could I use a type B mcb I guess the capacitors have a large inrush which might trigger the type b mcb but when charged you would have better protection with a type b than a type c? I have some adjustable time delay relays (0-30mins) 10amp I could use so the precharge circuit always comes on say 1 minute before the PSU powers on.

If so how the hell do I make one I read something about precharge resistors but have no idea where to start.

[Desertboy]

Came today but missing the top metal plate! I think the one on my old transformer will work fine but still poor maplins I do have both rubber protectors.

I was hoping it would straight swap but not so sure it will I might just get away with it and a hammer ;)



Not going to wire it up until I have an MCB, replacing the rectifier as well, going to leave the caps in place.

Think I traced the problem to a poor crimp causing the initial problems and we think my friend reconnected the bridge rectifier backwards on the output but no one can be sure.