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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => AC Power and Grounding => Topic started by: David Allred on November 20, 2013, 02:13:44 PM

Title: Rack grounding to prevent ground loops or other noise
Post by: David Allred on November 20, 2013, 02:13:44 PM
The rack for a permanent install will have a DBX Zone-pro, several music sources, and a wireless mic.  All on a rackmount power strip on a dedicated 20A circuit.
Also in the rack will 4) RMX2450 amps.  Each on it's own 20A circuit.

Should all chassis be grounded together though the rail?  If so, do I need to grind paint at strategic locations, run a tap through tapped holes to remove paint, etc?  Is there a better / alternate way?  Is it even needed?
I will be using the barrier strips for signal input.   Is the ground of each input attached to the chassis?  Can I / should I use that as the ground points by jumping from one unit to the other?  Can I assume that the wire could just be signal size (20-24 awg)?
At this point, earth ground is made though all units power cords, correct?

Thanks,
David
Title: Re: Rack grounding to prevent ground loops or other noise
Post by: John Roberts {JR} on November 20, 2013, 02:39:05 PM
Modern products properly designed do not need any additional consideration. Screw then in, plug them in, voila (sp?).

JR
Title: Re: Rack grounding to prevent ground loops or other noise
Post by: Kevin Graf on November 20, 2013, 05:23:20 PM
The Middle Atlantic paper has excellent coverage of rack power wiring.

Integrating Electronic Equipment and Power into Rack Enclosures
Optimized Power Distribution and Grounding for Audio, Video and Electronic Systems

http://www.middleatlantic.com/pdf/PowerPaper.pdf
Title: Re: Rack grounding to prevent ground loops or other noise
Post by: Lyle Williams on November 21, 2013, 03:06:01 PM
Quote from: John Roberts {JR} on November 20, 2013, 02:39:05 PM
Modern products properly designed do not need any additional consideration. Screw then in, plug them in, voila (sp?).

JR

Agree++.

Gear will get grounded through power and by being bolted into racks (no need to scrape paint.)

Safety-ground wise if there is a metal power outlet strip I'd expect power ground to be tied to the rack there.  If you just have a plastic power outlet strip then the rack will get grounded indirectly via the equipment and rackmount ears; not perfect but very very common.)