How do you imitate ground? - Page 1
Forum section: electronics / projects

author: jmctech
author_rank: Contributor
timestamp: October 07, 2016, 01:48:36 am
content: I am working on a project that will basically imitate faults on low volt electrical lines. We use testers made by JDSU and Fluke that need a ground reference to fully test a cable pair for things like opens, shorts, capacitive balance across a pair and also to ground. My question is how would I imitate ground reference?Thanks for looking and any help you could provide.Jason

author: singapol
author_rank: Frequent Contributor
timestamp: October 07, 2016, 05:47:46 am
content: You mean this?What do you mean; the output is "ground referenced"?http://www.spellmanhv.com/Technical-Resources/Application-Notes/AN-01http://www.aptsources.com/resources/pdf/Floating%20Output.pdf

author: jitter
author_rank: Frequent Contributor
timestamp: October 07, 2016, 06:13:45 am
content: Quote from: jmctech on October 07, 2016, 01:48:36 amI think the first question you must try to find the answer to is "what does 'referenced to' mean?".Once you understand that, your question above will be answered automatically.Singapol's links should get you on your way.

author: daqq
author_rank: Super Contributor
timestamp: October 07, 2016, 06:23:14 am
content: QuoteSorry, couldn't resist.

author: jitter
author_rank: Frequent Contributor
timestamp: October 07, 2016, 10:54:14 am
content: On a more serious note, a former colleauge used to live in Peru and earting was often done by running a wire to a wall of a building...

author: Back2Volts
author_rank: Unknown
timestamp: October 07, 2016, 02:16:51 pm
content: Quote from: daqq on October 07, 2016, 06:23:14 amI almost posted a flower pot. You beat me to it!

author: Marco
author_rank: Super Contributor
timestamp: October 07, 2016, 02:54:22 pm
content: Quote from: jmctech on October 07, 2016, 01:48:36 amI prefer to use ground as a synonym for circuit virtual ground, because that's how it's almost always used anyway. For actual ground I'll use the tautology earth ground.Why would you want to imitate ground reference? What's wrong with simply using earth ground? In theory you could dig a huge pit, put an electrically insulating liner in it, fill it with dirt and some water, put some grounding rods in it and have an imitated electrically floating earth environment ... but for what purpose?

author: jmctech
author_rank: Contributor
timestamp: October 07, 2016, 11:12:58 pm
content: Quote from: Marco on October 07, 2016, 02:54:22 pmIt is gonna be a portable device that will be used in different training areas. A reliable ground will not always be available. The other issue is these tester send some type of impulse down the ground connection. With a single person testing it isn't an issue, but when we have 8 or 10 of these testers connected to a common ground source they interfere with each other.Sent from my SAMSUNG-SM-N920A using Tapatalk

author: retrolefty
author_rank: Super Contributor
timestamp: October 07, 2016, 11:51:57 pm
content: Quote from: jmctech on October 07, 2016, 01:48:36 amI too think you are reading more into the 'requirement' then needed. Does the Fluke have an operations manual showing proper hook-up for DUT cable? I bet they just require that the ground lead be attached to any shielding lead(s) in the cable to perform all the measurements you stated.

author: jitter
author_rank: Frequent Contributor
timestamp: October 08, 2016, 06:07:33 am
content: Quote from: retrolefty on October 07, 2016, 11:51:57 pmAgreed.That was the reason for my first reply in this thread.What testers are they exactly? I'd like to look up a manual.

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 08, 2016, 07:26:46 am
content: Quote from: Back2Volts on October 07, 2016, 02:16:51 pmanother solution...