New user - Connecting high-current tools

1

I imagine this question is asked often, and I feel like this info should be readily available for new customers setting up, but I’m struggling to find answers. I have a number of large wood working tools in our makerspace that I want to control access to. I already set up a 15A Compound Miter Saw by cutting the power cord and wiring it directly via the screw terminals inside, bypassing the 10A fuse with a short wire, as I saw instructed in one of the documents. This felt way to “hands on” for what I thought was more of a polished appliance / interface. It worked, but I already know I’m going to have to come up with ways to handle operation with some tools that require higher voltage and current.

I see mentions of using the relay inline with the E-stop, etc, but I don’t see any examples people have showing where they did it. I’m sure I could figure it out, but I’d love to learn from mistakes of others, and the suggestions of “if I were to do it again I’d do it differently” which always seem to come AFTER all the trial and error.

The Fabman website doesn’t seem to have any of this type of documentation, does it? Has anyone documented this well for others to see? Thanks!

2

For higher-current or higher-voltage tools, the recommended approach is not to run the machine power directly through the Fabman Bridge. Instead, you should use a contactor:

  • The Fabman Bridge relay only switches the control side.
  • The relay then activates a contactor, and the contactor handles the actual machine power.
  • This way the Bridge is only switching a low control current, while the contactor safely switches the high load.

This is exactly how Fabman recommends connecting loads above the internal relay rating or 3-phase machines. There is an official guide here:

:arrow_right: Connecting Loads Greater than 16 A or 3-Phase Machines - Fabman Help Guides

The example in the guide shows a 3-phase setup, but the principle is the same for single-phase machines — just use an appropriately rated single-phase contactor.

If you’re unsure about wiring or local electrical regulations, involving a qualified electrician is highly recommended.

Hopefully this helps as a starting point, and maybe others can also share photos or lessons learned from their own setups.

Welcome to the community, and good luck with your installation!

Roland