Aluminium Profile Type Router - Initial questions

[Neale]

Personal view - there is little point in providing fuses for the drivers. A fuse will never "protect" a driver as the semiconductors in the driver will let out the magic smoke well before the fuse can react in the event of a major fault (and I'm thinking short-circuited motor wires, for example). If the built-in protection doesn't work, then it's already too late for a fuse. Where a fuse might help is in the output of the driver power supply, or maybe in the input to it. In the event of a fault in a driver that causes a high current draw, this will protect the power supply. In fact, the only electrical fault that has happened in my own control box was an internal short in the toroidal transformer which took out the fuse on the input (mains) side - fortunately. Generally speaking, fuses do not "protect" equipment - they help stop wiring, etc, bursting into flames when something has already failed. As I say, this is a personal view and others are paranoid about fuses everywhere. Be interesting to hear if these fuses have ever "saved" anything!

[JAZZCNC]

Personal view - Be interesting to hear if these fuses have ever "saved" anything!

My personal view is that it's stupid not to fit a fuse just to save a few pence. Why risk an £80 drive for the sake of an 80P fuse to protect from the unknown.!.

To answer the question have they ever "saved anything" then it's a BIG FAT YES I've had many cases where things like loose wires have shorted or been rubbed through etc. The point being your not actually always trying to protect the device but the system as a whole from unforeseen circumstances so spending a few quid more for fuses to protect valuable parts of the control box is a No brainer to me.

[AndyUK]

Be interesting to hear if these fuses have ever "saved" anything!

I've already buried the spindle in the work a couple of times, both times have 'gently' blown the VFD fuse before any damage was caused elsewhere. The power loss to the VFD also causes a fault on the controller so stops the motors, which is kinda nice.

I have this for the cabinet layout - does it look OK or any issues?

Three things spring to mind:

• VFD Spacing against internal walls. Read the manual for how far it should be away to allow adequate air flow.
• I'd keep earth near Line and Neutral, thats where it comes in after all, and a lot of the big ticket earthing items will be mains voltage.
• You've made a good start trying to separate voltage levels, but the 5V PSU should be at the low voltage end of the cabinet rather than its current position near 65V DC.
• Think about air flow through the cabinet - At the moment your drivers will get decent flow, but the VFD won't. What direction are those fans? I orientated my drivers to allow maximal air flow through their heatsinks, at the moment your heat sinks are at 90 degrees to the air flow.

Will it work in its current state? Sure. None of these things are big issues, just minor points.

I'm planning to buy these - could someone confirm they are OK choices, especially the contactor! Looks like it is DC

https://www.rapidonline.com/mean-wel...cy-psu-85-5684
https://www.rapidonline.com/schneide...tactor-66-1939

You've gone for the high efficiency and expensive one, is there any reason? This is the alternative to save £10.
https://www.rapidonline.com/mean-wel...il-psu-85-5678

Contactor seems okay.

Couple other questions from the never ending list:)
- Do I need to Fuse the drivers? They have overcurrent/voltage but I notice some people have?
- Are EMI filters needed with decent star grounding? I'm planning to add the EMI filter option on the transformer.

Extra fuses won't hurt.
The advice I found at the time was that some people needed to plug the VFD in at the other end of the workshop to reduce the noise back from it, and I wanted to be able to power everything from the same socket. The EMI filters I used were about £5 each, and although I have no idea if they're needed or not, they do allow me to operate without noise issues with everything running off the same 13A socket.