Bypass PIR Motion Sensor for Earth in Clean Manner

[mattjones]

I’ve got a basic PIR motion sensor that I’m wiring into my garage just before the ceiling light.

I’ve fitted it all fine and it works, however the light fitting requires an earth but the sensor doesn’t have a space for it in its terminal blocks. This is no problem and I’ve just joined the input earth and output earth with a wago and I was hoping to just put it inside the sensor but unfortunately the lid doesn’t perfectly close (I’m reasonably sure it’s electrically safe).

It closes just about enough for me to leave it for now, but I’m not particularly happy with it - what’s the cleanest/slickest way to have the earth bypass the motion sensor (it’ll be visible on the garage joists)?

On another (unrelated) note, the sensor just has a single side of a terminal block for the in and out neutral, do fittings not bother with a better solution? It feels a bit outdated just trying to cram two neutral wires into one side of a terminal block, but I guess it is cheaper…

Cheers.

 

[James]

There are lots of small enclosures you could use for jointing the cables outside the sensor.
from wagos own boxes to small adaptable boxes, it’s all about what will fit in the space you have available.
could you use a square box and mount the sensor to the lid?

some pictures of the application might help us.

 

[mattjones]

There are lots of small enclosures you could use for jointing the cables outside the sensor.
from wagos own boxes to small adaptable boxes, it’s all about what will fit in the space you have available.
could you use a square box and mount the sensor to the lid?

some pictures of the application might help us.

There are lots of small enclosures you could use for jointing the cables outside the sensor.
from wagos own boxes to small adaptable boxes, it’s all about what will fit in the space you have available.
could you use a square box and mount the sensor to the lid?

some pictures of the application might help us.

Sure. I’ve attached a photo. It’s pretty simple and simply hanging from an exposed joist so space isn’t an issue. I’m just more concerned about the installation looking a bit funny.

If I used an additional small box how would everything join up? Would I join the earth inside the box then pass live and neutral out to the sensor then back in again?

 

[Lucien Nunes]

The sensor would only need three connections: permanent (supply) line, switched line, and neutral, the latter teed in to the light neutral at the junction box. Therefore four Wagos / terminals in the junction box. PL, SL, N & E.

 

[mattjones]

The sensor would only need three connections: permanent (supply) line, switched line, and neutral, the latter teed in to the light neutral at the junction box. Therefore four Wagos / terminals in the junction box. PL, SL, N & E.

Right, but how would I wire this - less electrically more equipment and installation wise?

I know the current cabling would go into the junction box, and then go out to the light, but how would I get the PL and N to the sensor? Should I just use standard twin and earth but with the earth line disconnected/taped off at the end?

Likewise on the way back I only need the SL, right, would I just only connect the L in the twin and earth going back? And to confirm, that would mean I'd have one cable going there (from the junction box to the senro) and one going back, right?

 

[Lucien Nunes]

Triple-and-earth or 4-core flex would be ideal. The sensor would not need the earth, but I wouldn't re-purpose the green/yellow core in 3-core as the SL.

 

[mattjones]

Triple-and-earth or 4-core flex would be ideal. The sensor would not need the earth, but I wouldn't re-purpose the green/yellow core in 3-core as the SL.

Ah perfect, thank you. Did not know triple-and-earth/4-core-flex was a thing. Why would flex be ideal, just for an ease of use? I assume it is fine to have the PL going one direction and SL going the other in the same wire?