Yet another fuse question

[Konstantin]

I am finaly putting my 3 axis OS discrete modular boards togheder with the chopper board. God bless OS CNC

Got myself a PSU 24V 30A. PSU label tells "Caution unit requires external fusing". I plan to use 3 motors for now, 5.2V 1.4A/phase. Mains 115V.
How to use fuses apropiately.


Konstantin

[Alex S.A]

One suggestion woulb be put them in line with motor.

[Konstantin]

Well Id like to protect everythig, the PSU and the steppers as well.
Have anyone drawn a diagram anywhere?

Konstantin

[arvidb]

Is this a linear power supply (transformer + rectifier + capacitors)? In that case you should put a fuse before the PSU, on the mains input. 24 V * 30 A = 720 W output => 720 W / 115 V => 6.3 A on the primary side. A 10 A slow fuse might work here (you can increase it somewhat if it tend to blow when you switch the PSU on).

This protects the PSU. To protect motors and drives you need another fuse, this time between the PSU and drivers. I'm not sure how to calculate current draw of stepper drivers, but it depends on type of driver (chopper?) and on how you connect your steppers (series/parallel?).

Arvid

[Konstantin]

Is this a linear power supply (transformer + rectifier + capacitors)? In that case you should put a fuse before the PSU, on the mains input. 24 V * 30 A = 720 W output => 720 W / 115 V => 6.3 A on the primary side. A 10 A slow fuse might work here (you can increase it somewhat if it tend to blow when you switch the PSU on). This protects the PSU. To protect motors and drives you need another fuse, this time between the PSU and drivers. I'm not sure how to calculate current draw of stepper drivers, but it depends on type of driver (chopper?) and on how you connect your steppers (series/parallel?). Arvid

Thanks Arvid.


Konstantin