Wenatchee Home Inspections

                                      
             Square D


Coming to a panelboard near you barriers on the lugs and terminations of service conductors. I am seeing these barriers all the time now in new construction and pretty much all the panels installed since the beginning of 2017.

As for Washington State with the 2017 NEC adoption in effect July 1st, 2017  a new requirement was added for barriers to be placed in all service panelboards so that no uninsulated, ungrounded service busbar or service terminals be exposed to inadvertent contact by persons. This requirement was already in place for switchboards and switchgear sot now it has been expanded to service panelboards in 2017.

                                                                               Siemens

From Siemens-
“Touchsafe barriers are required for any single main service entrance application for a panel covered under UL 67. Line Terminal Barriers will be included in Main Breaker Load Centers and Single Main Meter Combos manufactured after January 1, 2017. “

                                   
                                                                                   Siemens

This requirement has been identified as a safety concern by installers and proponents of electrical safety in the workplace.

From UL-

“UL67 Section 5.4 Service Equipment

More than 8% of work related deaths is caused by electrocution

According to the Occupational Safety and Health Association there are more than 92 work-related deaths per week. A little over eight percent of those are caused by electrocution, most of which occur by inadvertent contact with energized objects.

The UL67 standard has been updated for the purpose of enhancing safety in electrical distribution panels. The revision, which takes effect January 1, 2017, requires panel manufacturers to provide protective devices that guard against inadvertent contact with exposed energized parts. All manufacturers must comply with the UL changes, but the methods they use will vary. The new requirement also appears in the 2017 National Electrical Code® (NEC), with timing subject to state-specific adoption.

The change applies any time a panel is being used as service entrance equipment, whether it’s a main breaker load center, panelboard, or combination service entrance device (CSED) application. Even with the barrier in place, the panel must still be de-energized before removing the dead-front, but the new requirement guards against inadvertent contact with any exposed line side parts that would still be energized unless the upstream meter is pulled.”

       

They are recomming installation of these barriers in existing installations also.

From Square D-

“Square D offers compliant barrier solutions for Square D Schneider Electric brand load centers, panelboards, and CSEDs. The required barrier kits now come standard with every service entrance intended panel we manufacture, but can also be ordered separately for replacement, convertible main applications, or for upgrading a panel that was installed before the new requirement was put in place.”

One thing it may inhibit home inspectors is that we may not be able to identify the “service conductor” material with these barriers in place.

In addition to the new requirement there was an exception that was also added eliminating the barriers at panelboards installed to comply with the requirements of 408.36, Ex. No. 1, 2, and 3. These exceptions to 408.36 address the "six means of disconnect" rules and the old "split-bus" panelboards that could be present.


So here is the code which is in article 408 of the NEC.

From the 2017 NEC-

408.3 Support and Arrangement of Busbars and Conductors.

(A) Conductors and Busbars on a Switchboard, Switchgear, or Panelboard. Conductors and busbars on a switchboard, switchgear, or panelboard shall comply with 408.3(A)(1), (A)(2), and (A)(3) as applicable.

(2) Service Panelboards, Switchboards, and Switchgear.
Barriers shall be placed in all service panelboards, switchboards, and switchgear such that no uninsulated, ungrounded service busbar or service terminal is exposed to inadvertent contact by persons or maintenance equipment while servicing load terminations.

Exception: This requirement shall not apply to service panelboards with provisions for more than one service disconnect within a single enclosure as permitted in 408.36, Exceptions 1, 2, and 3.

                                                                        Eaton/Cutler Hammer

2014  NEC
(2)Service Switchboards and Switchgear.

Barriers shall be placed in all service switchboards and switchgear such that no uninsulated, ungrounded service busbar or service terminal is exposed to inadvertent contact by persons or maintenance equipment while servicing load terminations.

From Siemens-
https://www.downloads.siemens.com/download-center/Download.aspx?pos=download&fct=getasset&id1=BTLV_47038

From Schneider-
https://www.schneider-electric.us/en/work/products/explore/service-entrance-barriers/residential/

“Remember that current always returns to its source through either an intentional or accidental path - electrons don’t care and they don’t read schematics!”

Gerke, D. and Kimmel, W

If you find any errors or have additional information that would expand on any code, building standards or manufacturer requirements please let me know.

NCW Home Inspections, LLC  is a Licensed Washington State Home Inspection service located in Wenatchee Washington serving Chelan County, Douglas County, Kittitas County, Okanogan County and Grant County Washington and the cities of Wenatchee, Leavenworth, Cashmere, Oroville, Cle Elum, East Wenatchee, Quincy and many more…  

Your Wenatchee and Chelan Professional Real Estate, Home and Structural Pest Inspection Service

Instructor- Fundamentals of Home Inspection-  Bellingham Technical College

WA Home Inspector Advisory Licensing Board

www.ncwhomeinspections.com                                                   509-670-9572

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