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arc flash signs #85046 05/24/03 10:50 AM
Joined: Jun 2001
Posts: 196
Cindy Offline OP
110.16 Flash Protection.
Switchboards, panelboards, industrial control panels, and motor control centers that are in other than dwelling occupancies....

so this excludes 480v VFD's??? contactor panel? UPS? right?

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Re: arc flash signs #85047 05/25/03 10:38 AM
Joined: Feb 2003
Posts: 169
russ m Offline
The definition of panelboards and switchboards seems pretty broad. I think the object of this code would be to protect someone from arc flashes that could occur if a switch closed while the equiptment door (cover) was open for servicing. You would have to judge each case on its own, is there a possibility of an arc flash under normal operating conditions? Plus " are they likely to require examination, adustment, servicing, or maintenance while energizied". Has the equipment been tested and listed for use as it is, and did it come with instructions on its installation and use.


[This message has been edited by russ m (edited 05-25-2003).]

Re: arc flash signs #85048 05/25/03 09:38 PM
Joined: Apr 2002
Posts: 2,527
Bjarney Offline
No personal offense is meant, but realistically, it's splitting hairs to differentiate drives and contactor panels from industrial-control panels, particularly for basic energized troubleshooting sanity. Prevention of grisly deaths and injuries has evolved into the practical Article 110 minimum requirements over many code editions. Recognition and adaptation of the rudimentary physics in Ralph Lee’s early-1980’s work on arc-blast fundamentals are past due.

UL-standards boilerplate should eventually catch up with code-mandated signage, and become part of the routine equipment-manufacturing process like other tagging.

Re: arc flash signs #85049 05/26/03 04:57 PM
Joined: Jun 2001
Posts: 196
Cindy Offline OP
have to wonder why the code was worded that way if they meant to include the above..... maybe they think its obvious to the most casual observer... i'm pretty casual, average intelligence... why do i have to wonder what they meant?

Re: arc flash signs #85050 05/26/03 06:03 PM
Joined: Apr 2002
Posts: 2,527
Bjarney Offline
Again, no offense intended, but the situation probably takes on new meaning when you’re in front of the subject device with someone insisting, "So exactly when is it going to be working again?!?"

Re: arc flash signs #85051 05/26/03 07:26 PM
Joined: May 2002
Posts: 1,716
Roger Offline
have to wonder why the code was worded that way
this is the sole reason for some very heated arguments. Unless we could word the code the way we wanted, we will continue to "wonder why".

..... maybe they think its obvious
Maybe, maybe not, it may just be poor wording period. You show that you are not satisified with the wording, so you question it. This shows more than complacency on your part. As others would say, don't be scared to get involved,add your comments to the code making process.


Re: arc flash signs #85052 05/26/03 10:02 PM
Joined: Jun 2001
Posts: 196
Cindy Offline OP
what confused me is the "industrial control panels" and UL says.....

"Industrial Control Panels (NITW)

Products Listed under this category include industrial control panels, which are factory wired assemblies of industrial control equipment such as motor controllers, switches, relays and auxiliary devices. The panels may include disconnect means and motor branch circuit protective devices.

This category also covers industrial panel enclosures which are intended to house open type industrial control panels or individual items of industrial control equipment as noted above.

The basic requirements used to investigate this category is Subject 508A, Outline of Investigation for Industrial Control Panels."

just wanted to know when to put the signs on the panels.... so i'm going with PLC's, contactor panels, VFD's, UPS's and i guess any enclosures that have the devices [above] inside.
thanks for your ideas again


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