24vdc and rs-485 in same condiut

seand27

Member
Hello, Everyone!

We have a customer that is running 24vdc and RS-485 communications lines in the same conduit for a solar PV monitoring application. The questions is wheather the 24vdc needs to be grounded in this application? I have searched quite a bit and can't seem to find any best practices published on this topic. Does anyone have any thoughts on this? Much appreciated!!

Sean
 

petersonra

Senior Member
Hello, Everyone!

We have a customer that is running 24vdc and RS-485 communications lines in the same conduit for a solar PV monitoring application. The questions is wheather the 24vdc needs to be grounded in this application? I have searched quite a bit and can't seem to find any best practices published on this topic. Does anyone have any thoughts on this? Much appreciated!!

Sean
is the 24VDC a class 2 circuit?
 

petersonra

Senior Member
Hi, Bob.

Thank you so much for posting a response so quickly. Honestly, I am not sure if it is a Class 2 circuit or not, but I will try and confirm that. The device generating the 24vdc in this case is this Weidmuller power supply:

https://catalog.weidmueller.com/catalog/Start.do?localeId=en_DE&ObjectID=8739140000

If this is a class 2 circuit, should the 24VDC be grounded?

Cheers!
Sean
The power supply label that you linked to shows it is a listed class 2 power supply so it probably is a class 2 circuit. And equipment grounding conductor is not likely required. I am not real sure if you are asking if an equipment grounding conductor is required or if one leg needs to be grounded.
 

don_resqcapt19

Moderator
Staff member
There is no requirement in the NEC to ground one of the legs of the power supply output circuit. 250.162 covers if a DC system needed to be a grounded system, and you system is not required to be a grounded system.
 
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