bonding 1900 boxes?

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elect4

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Isn't code that if your running conduit ( emt for example) and set a 1900 box , that because it has eccentric/concentric knockouts it would need to be bonded with the equipment ground passing thru with a bonding pigtail or whatever I hardly ever see this done. usually people will make their taps close it up and no bond jumper. and ive seen this from several people, several elect companies
 
what you are talking about is required at services 250.92, but not necessarily elsewhere - 250.96 (2005)
 
elect4 said:
Isn't code that if your running conduit ( emt for example) and set a 1900 box , that because it has eccentric/concentric knockouts it would need to be bonded with the equipment ground passing thru with a bonding pigtail or whatever I hardly ever see this done. usually people will make their taps close it up and no bond jumper. and ive seen this from several people, several elect companies
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Whats the voltage?

IMO if there are joints in the box, you ground it.

250.97 Bonding for Over 250 Volts.
For circuits of over 250 volts to ground, the electrical continuity of metal raceways and cables with metal sheaths that contain any conductor other than service conductors shall be ensured by one or more of the methods specified for services in 250.92(B), except for (B)(1).
Exception: Where oversized, concentric, or eccentric knockouts are not encountered, or where a box or enclosure with concentric or eccentric knockouts is listed to provide a reliable bonding connection, the following methods shall be permitted:
(1) Threadless couplings and connectors for cables with metal sheaths
(2) Two locknuts, on rigid metal conduit or intermediate metal conduit, one inside and one outside of boxes and cabinets
(3) Fittings with shoulders that seat firmly against the box or cabinet, such as electrical metallic tubing connectors, flexible metal conduit connectors, and cable connectors, with one locknut on the inside of boxes and cabinets
(4) Listed fittings

250.148 Continuity and Attachment of Equipment Grounding Conductors to Boxes.
Where circuit conductors are spliced within a box, or terminated on equipment within or supported by a box, any equipment grounding conductor(s) associated with those circuit conductors shall be connected within the box or to the box with devices suitable for the use in accordance with 250.148(A) through (E).
Exception: The equipment grounding conductor permitted in 250.146(D) shall not be required to be connected to the other equipment grounding conductors or to the box.
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elect4 said:
Isn't code that if your running conduit ( emt for example) and set a 1900 box
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nakulak said:
what you are talking about is required at services 250.92,
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I must be tired, I can't think of a smart remark involving a service and a 1900 box.
 
480sparky said:
Type of KOs are irrelevant. 314.40(D).
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Why would the KO's be irrelevant? What about 250.97? For less than 250 volts the type of KO wouldn't matter. Above 250 volts you would need to meet the requirements that Chris posted.
 
infinity said:
Why would the KO's be irrelevant? What about 250.97? For less than 250 volts the type of KO wouldn't matter. Above 250 volts you would need to meet the requirements that Chris posted.
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i believe those knockouts on 4 inch square boxes are listed for bonding
 
electricalperson said:
i believe those knockouts on 4 inch square boxes are listed for bonding
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You're probably right but you know what happens when you assume.:rolleyes:
 
If the KOs are of the eccentric type then they are listed for bonding.

Main Entry: 1ec?cen?tric

Pronunciation: \ik-ˈsen-trik, ek-\



2 a: deviating from a circular path; especially : elliptical 1 <an eccentric orbit> b: located elsewhere than at the geometrical center; also : having the axis or support so located <an eccentric wheel>
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There were changes made to the UL Standard a number of years ago. As Bob mentioned, eccentric KOs are designed to permit the flow of fault current. In most circumstances one will not be required to bond around eccentric KOs. Concentric KOs in the newer boxes are also listed as suitable, but I do not see too many concentric KOs anymore in the boxes used in the field.


If you are working in an older box, you may need to bond around the concentric KOs.



From UL White Book


METALLIC OUTLET BOXES (QCIT)


CONCENTRIC OR ECCENTRIC KNOCKOUTS​
All boxes with concentric or eccentric knockouts have been investigated

for bonding and are suitable for bonding without any additional bonding
means around concentric (or eccentric) knockouts where used in circuits​
above or below 250 V, and may be marked as such.





 
Pierre C Belarge said:
There were changes made to the UL Standard a number of years ago. As Bob mentioned, eccentric KOs are designed to permit the flow of fault current. In most circumstances one will not be required to bond around eccentric KOs. Concentric KOs in the newer boxes are also listed as suitable, but I do not see too many concentric KOs anymore in the boxes used in the field.


If you are working in an older box, you may need to bond around the concentric KOs.



From UL White Book


METALLIC OUTLET BOXES (QCIT)


CONCENTRIC OR ECCENTRIC KNOCKOUTS​
All boxes with concentric or eccentric knockouts have been investigated

for bonding and are suitable for bonding without any additional bonding
means around concentric (or eccentric) knockouts where used in circuits​
above or below 250 V, and may be marked as such.
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i was hoping someone would post that. i lost my copy of the UL white book
 
elec4,

Yes, you have to pigtail the EGC to the box, but in this case it's not because

of the concentric k.o.'s, it's because anytime an EGC terminates in a box it

also must ground the box.
 
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