Grounding in a Plastic Toolbox

So, one of my pipe dreams is going over to electric, and I'm interested in doing a plastic toolbox mobile build. Safety is of utmost concern to me, since I'm a n00b with electrical. So... how do I go about grounding inside a plastic toolbox-based enclosure?

I am getting a sub panel put in my garage and going to get a 4-prong 240v outlet installed for this purpose, on a GFCI'd 30A breaker. However, the idea of simply routing all connections thru to the ground on this doesn't pass my 'smell test'. Maybe its just paranoia, but I'd really like to have some sort of additional ground inside the enclosure itself.

I have looked thru the toolbox build posts on this (very awesome) forum and haven't found any explicit documentation of how folks ground out their plastic toolboxes; is it not necessary, or am I missing it? Any suggestions on how I could go about adding a ground post/plane w/o over-complicating my build? It's totally in the hypothetical phase right so nothing is out of the realm of possibilities!

Thx in advance.

You can run all of your ground connections to a terminal block inside of your tool box. You will also need to run a ground wire from your terminal block to your power source i.e. fuse box, or the ground wire in the cord you are using. Last make sure all of your connections are jumped on the terminal block from your Ground wire to your power source.

Your ground will follow through the box to the keg skirt, or somewhere on your kettle. My box isn't grounded other than that.

ehedge20 said:

You can run all of your ground connections to a terminal block inside of your tool box. You will also need to run a ground wire from your terminal block to your power source i.e. fuse box, or the ground wire in the cord you are using. Last make sure all of your connections are jumped on the terminal block from your Ground wire to your power source.

Click to expand...

OK, gotcha! To confirm, in addition to my hot and neutral bus(s) I can add a ground bus too? I was debating this but I wanted somebody w/ some experience to corroborate.

pvburton said:

Safety is of utmost concern to me, since I'm a n00b with electrical.

Click to expand...

I would say, if you're a noob with electrical, you should get somebody with more experience to do the job for you. Especially when, having a plastic enclosure, you're adding the risk of fire to that of electrocution.

You should have a HOT bus, NEUTRAL bus and a GROUND bus. Your incoming power would connect there.

All connections of your electric brew system should ultimately terminate on one of those bus terminals.

Never switch a NEUTRAL or GROUND either with a manual switch, a relay contact or SCR.

Good luck!

Yes, add a ground bus. Exposed metal on your control box needs to be grounded. If the box is plastic, then of course it does not need to be grounded, but things like heat sinks technically should be grounded.

The idea here is that if a hot wire comes loose inside the box and rests against exposed metal, the exposed metal will become "live" and you will get shocked when you touch the metal. BUT, if that metal is grounded, then the breaker or fuse will blow when the hot wire touches the metal, and you will avoid the shock: the ground makes the fuse/breaker do its job.

I have a plastic toolbox build on here somewhere. I think I have an out-of-focus picture showing the inside of my box.

Thanks all, both for your concerns and pointers!

I plan on following theelectricbrewery and Tiber_Brew's setups, so hopefully safety is somewhat implicit there; also before first brew I plan to have my certified electrician who just put in the subpanel (finished today!) come and check it out and bless things.