Power Supply to MC050-120 what should be fuse rating ??

[Pankaj]

Hi,

We use MC050-120 controller in our application, I want to know if Power supply need to be fused??

It should be to protect controller as a general guideline but I am not sure what should be rating of fuse(A)?

I couldn't find any information in documents.

Pankaj

[FluidPowerTom]

When I was just getting started I'd asked this same question of the Help Desk, and there's no recommended fuse or or circuit protection needed to protect the PLUS1 controller.  The controller protects itself, so stuff like short circuits on the outputs aren't going to hurt it.  I think the only electrical ways that you'd really damage the controller are stuff like over voltage or high speed short circuit cycling.  Neither of these would really be prevented with a fuse. 

The only way that I've ever seen  PLUS1 controller permanently damaged was due to a small amount of water in CAN bus connectors that caused CAN wires to short circuit to ground and each other for rapidly and intermittently for a long period of time.

So, your selection of a fuse or circuit breaker, if you want one, is going to be based on your amp draw.  For example, if your controller and other components are drawing 15A total then I'd recommend a 20A fuse.

[bryantmorris]

So, your selection of a fuse or circuit breaker, if you want one, is going to be based on your amp draw.  For example, if your controller and other components are drawing 15A total then I'd recommend a 20A fuse.

As Tom said, fuse should be slightly above the highest current draw your system will cause. The MC controller datasheet's also include information on the maximum current allowed through the controller so that can also be used as a guide eg MC050-110 is 40 A sourcing, 8 A sinking. The higher sourcing current is due to the extra V+ pins compared to the number of GND pins on the controller.

http://files.danfoss.com/documents/plus%201%20mc050%20110%20and%20mc050%20112%20controllers%20data%20sheet/l1301752.pdf