Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

24vdc Positive grounding

Status
Not open for further replies.

JLBEngineer

Electrical
Apr 4, 2016
2
US
Is it acceptable in the US for a machine to have the positive terminal grounded on the 24vdc power supply?
The machine was developed in Japan.

Ran into a problem when connecting computer laptop to machine PLC seems to be a ground issue since the laptop
computer uses common (negative) on AC power supply (power plug has ground connection). Grounding issue was overcome by using a computer power supply with no ground on plug to the AC outlet.
 
Replies continue below

Recommended for you

I believe there are cars with positive grounds. You should use an optical isolation scheme on the communications line, rather than compromising safety.

TTFN
I can do absolutely anything. I'm an expert!
faq731-376 forum1529
 
If the "machine" requires -24VDC then sure..

Is the power supply part of the machine?
Does the instructions for the machine require an isolated supply?


 
A lot of older telephony systems used positive earthed supplies because it prevented corrosion of the metal conductors due to galvanic actvity between the metal and the mass of earth, rather than accelerating corrosion by actively driving the corrosion cell as would happen with a negative earthed system.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top