Emcoturn 120 lathe retrofit

here are my thoughts on the power wiring. what recommendations for fuses at these locations? Or are the locations wrong? I was planning to use the 25A ceramic holder/fuses in position 1 and the 6a/leg breaker in the "breaker" location but now I think these may be too large a value.

I don't have any actual fuses in my system, I use MCBs throughout. They are so cheap that it seems pointless not to.

I have a single 20A for the motors and two 3A ones for the switched and unswitched low-voltage supplies.

So, there is a 3-pole isolator switch (with only 2 poles in use) feeding a single 3A breaker and the main contactor. That breaker feeds a 24V supply for GPIO (and the main contactor) and a 12V supply for the PC. The main contactor then powers the 20A breaker for servo and spindle power and a second 3A breaker for the spindle gearbox clutches and brake.

The 20A breaker is C-rated for motor use. The 3A ones are not, but soon will be, as the 3A B-rated type tend to trip on the inrush current of the PSUs.

so I would want to ?

replace fuse 1 with 2 pole or 3 pole 20amp/pole MCP, how do I know if it is c rated?
replace "breaker" with 2 pole 3A/pole MCB
replace "5" with 2pole 10A/pole MCB
get rid of 2,3,4 and 6.

LutzTD wrote: replace fuse 1 with 2 pole or 3 pole 20amp/pole MCP, how do I know if it is c rated?.

It says on the front. (well, it does here, things might be different where you are).

www.tlc-direct.co.uk/Main_Index/Consumer...ssories_1/index.html

There are types A and D too, but you rarely see them.
A bit of extra detail: www.tlc-direct.co.uk/Technical/Distribution/Mcb.htm

thanx, I also did a little research. I like to stick with names I know when it doesnt cost too much more. I ended up getting 3 double pole breakers made by Allen Bradley, a 1489-A2C200, 1489-A2C100 and a 1489-A2C030, which are 20A, 10A and 3A respectively. The third digit "C" in the second part of the number designates the C rating, ( I downloaded the catalog to find this out) These are from surplus dealers on ebay. They were about $15 each for NOS units, so not too much different.

I like to work in graphics to wrap my head around it, so here is my power layout