Ethernet Connection To Purged Panel

[cowski]

I'm installing an HMI in a purged enclosure (CI/II D1). The purge controller (P+F 6000 series) will close a contact that supplies 24VDC power to the HMI when the area inside the enclosure is safe.

Do I need to handle the ethernet connection to the HMI the same way as DC power? So I run ethernet through a mechanical relay that disconnects when the panel isn't purged? Is this even possible? Maybe with gold plated relay contacts -- even then there would be impedence issues...?

Or I could run the HMI's ethernet through a seperate switch that's powered down when the HMI panel isn't purged. Or I could make the ethernet connection to the HMI intrinsically safe...

Does anyone else worry about this? Am I being stupid? Ethernet is around ~2V. Can I just connected the ethernet cable to the HMI and not worry about it?

 

[PaulMmn]

Is your Ethernet supplying Power Over Ethernet? That would up the voltage.

 

[petersonra]

I think you can get intrinsically safe barriers for Ethernet.

Otherwise run the Ethernet cable in through a seal.

 

[Shaneyj]

We use Solexy barriers for Ethernet connections.


Sent from my iPhone using Tapatalk

 

[cowski]

No, there's no power over Ethernet.

Ok. I was considering the Solexy barrier. I'm not sure if hard piping the ethernet cable would be enough, because it would be exposed inside the Nema 4 HMI enclosure when the purge is potentially not active...