Electronics: Tie 0V/GND to mains earth?

[skotl]

I'm gonna be using one of these inside an IP66 plastic case outdoors, powering an Arduino. There will be an antenna for the radio, which has a stainless steel nut, but no other external metal connections.

I'm probably over thinking this, and won't be inside the box while it's powered, but I am a little concerned if something catastrophic happened in the power supply and it decided to leak AC to either of the DC outputs. I can easily supply L,N+E to the box so was wondering whether there was any reason I shouldn't tie the 0VDC GND to the mains earth?

 

[m_c]

I probably wouldn't bother tying 0v/Earth for what you describe, however your could probably argue either way.

 

[Kayos]

The fact you have mentioned antenna for radio is the reason I wouldn't. I generally don't with that type of module anyway, as they are usually used to provide isolation as well as step down

 

[sako243]

What does the stainless steel nut connect to on the antenna? Is it meant to be a ground plane?

 

[Hotstuff]

It’s likely that your mains supply earth is at neutral potential. It could present a hazard outdoors if the arial is at true earth potential and is simultaneously accessible to the supply earth.

As long as you have adequate short circuit, overload & earth leakage protection to the supply and all components are suitable for their location, in theory, it should be just as safe as if it was located indoors.

Sounds like an interesting project; do keep us posted.

 

[ajlelectronics]

Keep the LV and mains supply isolated.

 

[skotl]

What does the stainless steel nut connect to on the antenna? Is it meant to be a ground plane?

Nope. It’s for use in a plastic enclosure.
I can, of course, replace that nut with a nylon one.

—-

Ok - thanks all. Looks like keeping LV isolated is the way to go.

 

[sako243]

What I meant was is the nut meant to be bolted to a ground plane? On some aerials (e.g. CB) the nut to fix it is usually meant to be grounded (signal ground) to provide the ground plane for the monopole antenna.

 

[masleeve]

The key is the PSU is isolated .
If you bond the earth across you are losing the advantage.
In the modern mains supply there may be repairs that bond the earth and neutral together further back in the network.
In the event of a neutral break elsewhere your earth could rise in potential.