ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
VDE 0100 to introduce AFCIs
by sparky. 01/20/18 05:09 PM
MRI LED lights dimmer control replacement - wow!
by Potseal. 01/19/18 08:52 PM
Video: Inventor of the GFCI self-testing shocks
by Bill Addiss. 01/17/18 11:11 PM
FPE in Germany
by HotLine1. 01/17/18 07:07 PM
Fujifilm Recalls Power Adapter Wall Plugs
by Admin. 01/16/18 07:04 PM
New in the Gallery:
Housebilding DIY wiring
SE cable question
Who's Online Now
1 registered members (sparky), 10 guests, and 10 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Three Code Questions #77583
06/24/01 07:37 PM
06/24/01 07:37 PM
Joe Tedesco  Offline OP
Member
Joined: Oct 2000
Posts: 2,749
Boston, Massachusetts USA
From "Della" <della@acmgfcu.net>
To: <joetede@ix.netcom.com>

I work in a factory with printing presses and other machines that take printed
cartons and fold and glue them to be sent to other companies who package things like powdered laundry detergent and clumping cat litter in them.

We use mainly EMT and not rigid conduit.

My questions are:

1) Should we pull in equipment grounding wires for the electrical outlet receptacles and lighting (120 volt and 277 volt) instead of relying on the tubing for equipment grounding?

YES


2) Is it okay to replace double insulated tool plugs with 3 prong plugs, although there is no ground wire attached to that plug, or is it necessary to replace them with 2 prong plugs?

NO, USE SAME

3) Is it necessary to bond peices of machinery that have no mechanical connection between, them but are connected through conduit and part of the same system?

YES, TO PREVENT STATIC ELECTRICITY

(example is for equipment that feeds the paper web to the printing presses and rerolls it as it comes off)

Thanks for any help you can give me in these matters.


Joe Tedesco, NEC Consultant
2017 / 2014 NEC & Related Books and Study Guides
Re: Three Code Questions #77584
06/25/01 04:18 PM
06/25/01 04:18 PM
Scott35  Offline

Broom Pusher and
Member
Joined: Oct 2000
Posts: 2,708
Anaheim, CA. USA
Joe,

I wish that more Q's from people [or Clients] were as simple to answer as these were!!!

Glad that you agree on #1 to include a supplimental EGC - even if the raceway is metallic!!! That's a point I'm personally trying to push, since once the conduit is separated by a broken coupling, the EGC is lossed - including a bonding conductor makes everything a bit more safe [not completely foolproof, though!!].
This is from the countless numbers of times I have seen EMT damaged at couplings, with one Ungrounded conductor being wedged against the "Load" side of the broken coupling - resulting in conduit[s] being a shock hazard to ground.

On #2, using a 3 wire [grounding] cord cap would have any metallic parts of the cord cap [i.e. Plug] connected to the EGC/grounding pin. In that case, there's once again a ground fault hazard to personnel which will not be tripping any OCPD, but would trip a GFCI after a person was being shocked! [only if GFCI was operating properly].

#3 - Major static [ESD] potential on a paper mill!! Even if the machinery wasn't that purpose, the solid ground bonding assures that all assemblies are as close to the same potential as possible.

Just wanted to add some stuff to your post, mainly so others can see where you are basing ideas from, along with showing a common interest from two or more members on the subjects.

Thanks for the post!!!

P.S. can you contact me soon in regards to the Instructor position??? Can't do it now, but maybe by October I'll have ample time for it.

Scott SET


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
Re: Three Code Questions #77585
06/25/01 06:27 PM
06/25/01 06:27 PM
M
Mike Wescoatt  Offline
Member
Joined: Jun 2001
Posts: 161
Cedar City, Utah
While doing some periodic testing today I looked around the room and saw two EMT tubes that had become seperated. Luckily all of the pipes in the building have a grounding conductor run in them.

I am all for running a grounding conductor in conduit.


Mike Wescoatt
Re: Three Code Questions #77586
06/25/01 07:43 PM
06/25/01 07:43 PM
Joe Tedesco  Offline OP
Member
Joined: Oct 2000
Posts: 2,749
Boston, Massachusetts USA
Scott:

The answers I gave, which were my personal opinions, were based upon some of my own personal experiences, and help to support Mike's comment.



[This message has been edited by Joe Tedesco (edited 07-07-2001).]


Joe Tedesco, NEC Consultant

Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
waymag
waymag
dallas, texas, USA
Posts: 67
Joined: January 2002
Show All Member Profiles 
Top Posters(30 Days)
Admin 20
sparky 16
Potseal 15
Popular Topics(Views)
243,576 Are you busy
180,374 Re: Forum
170,852 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.014s Queries: 14 (0.004s) Memory: 0.9607 MB (Peak: 1.0906 MB) Zlib enabled. Server Time: 2018-01-21 16:35:29 UTC