Newbie PSU calculations

[Soyb]

My workshop / man cave has a 30A supply split in to a lighting circuit and 2 16A MCB ring mains. The machine I am building is a 'light weight' CNC gantry router for cutting wood and possibly some aluminium (very slowly).

See http://www.mycncuk.com/threads/14590...-Gantry-Router

I am planning to use a 1 KW kress spindle and 4 x 5A closed loop stepper motors, so the electrical demand is quite low. I was going to rely on the consumer unit for my main protection and just have a No Volt Relay, On/Off switch and Emergency Stop on the mains side of the machine.

Electrics is not my thing, but I haven't killed myself yet.........

Is it worth putting a 6A MCB in the enclosure?

[JAZZCNC]

MCB's cost like £5 each and glass fuses like 50p so it's crazy not to use them IMO.
In my control boxes, I fit 3 x MCB's one for the Main toroidal PSU, VFD, and low voltage PSU's, the drives each have their own slow-blow glass fuse. So For less than £20 we are protecting over £400 to £500 worth of electronics and in worst-case scenario's, which happen more often than people realize property and life which are quite honestly priceless.!! . . . .Don't be stupid people, fit fuses and be safe.

[dazp1976]

MCB's cost like £5 each and glass fuses like 50p so it's crazy not to use them IMO.
In my control boxes, I fit 3 x MCB's one for the Main toroidal PSU, VFD, and low voltage PSU's, the drives each have their own slow-blow glass fuse. So For less than £20 we are protecting over £400 to £500 worth of electronics and in worst-case scenario's, which happen more often than people realize property and life which are quite honestly priceless.!! . . . .Don't be stupid people, fit fuses and be safe.

Actually Jazz.
That brings me to a question for you.
My A4 servo requires a 30A breaker but unless I import something (again), all I see around are 32A.
I want to double the 32A mcb in-line with 30A glass fuse.
Where do you get your glass fuse holders from?. Want a Din mounting type.
It's either that or drop down to a 25A mcb and hope it don't keep tripping off.

Already got some of the other mcb's and some AC relays for each to activate an estop if any trip off.

Cheers.
Daz.

[JAZZCNC]

Where do you get your glass fuse holders from?. Want a Din mounting type.

Like Neale says don't worry about the difference between 30A and 32A and even 25A won't complain until you would want it to anyway.

The Cartridge type fuses you can buy from any decent electrical supplier like RS and there are plenty on eBay also.