NEC Art 517.14

[Zane Bailey]

Can the #10 grounding conductor described in 517.14 be installed alone (not run with feeder or branch conductors) in ferrous raceway? If run alone is the ferrous raceway required to be bonded on both ends of the ferrous raceway? Does the code describe proper wiring methods for this type installation?

 

[Zane Bailey]

haven't heard back on this from anyone

haven't heard back on this from anyone

Can the #10 grounding conductor described in 517.14 be installed alone (not run with feeder or branch conductors) in ferrous raceway? If run alone is the ferrous raceway required to be bonded on both ends of the ferrous raceway? Does the code describe proper wiring methods for this type installation?

Does anyone out there have any insight on this they would like to share?

 

[luckylerado]

NEC does allow an EGC to be installed by itself in a raceway. In fact #6 and smaller are required to be protected 250.120C

As #10 is stated as the min size allowed I believe that 517.14 implies that the EGC should be sized per 250.122. Perhaps sized based on the largest OCP device since not installed with a branch circuit of feeder??

517.13 mandates the raceway be metal not necessarily ferrous, and meet the requirements of 250.118 to be considered an EGC

Yes, the raceway is required to be bonded by an approved method for your particular set of circumstances.

 

[retire09]

The way I have seen this done was by running a #10 single insulated green copper conductor from panel to panel in the electrical room. It just ran from ground bar to ground bar and secured exposed to the wall between. Sometimes they would run through a lug mounted on the bottom of the panels unbroken. All you are doing is bonding all the panels from various sources together.

 

[retire09]

The conductor is not a grounding conductor; it is a bonding conductor. It does not require protection or conduit and only needs to be #10 or larger and does not need to be sized.

 

[luckylerado]

It just ran from ground bar to ground bar and secured exposed to the wall between.

This is definitely in violation of 250.120(C)

(C) Equipment Grounding Conductors Smaller T han
6 AWG. Where not routed with circuit conductors as permitted
in 250.130(C) and 250.134(B) Exception No. 2, equipment
grounding conductors smaller than 6 AWG shall be protected
from physical damage by an identified raceway or cable armor
unless installed within hollow spaces of the framing members
of buildings or structures and where not subject to physical
damage.

 

[don_resqcapt19]

This is definitely in violation of 250.120(C)

(C) Equipment Grounding Conductors Smaller T han
6 AWG. Where not routed with circuit conductors as permitted
in 250.130(C) and 250.134(B) Exception No. 2, equipment
grounding conductors smaller than 6 AWG shall be protected
from physical damage by an identified raceway or cable armor
unless installed within hollow spaces of the framing members
of buildings or structures and where not subject to physical
damage.

The conductor in question is not an equipment grounding conductor.

 

[retire09]

250.120(c) is for equipment grounding conductors.
Those are arr run with the other circuit conductors in cables and conduits.
517.14 is a bond connection.

 

[Smart $]

The way I have seen this done was by running a #10 single insulated green copper conductor from panel to panel in the electrical room. It just ran from ground bar to ground bar and secured exposed to the wall between. Sometimes they would run through a lug mounted on the bottom of the panels unbroken. All you are doing is bonding all the panels from various sources together.

I would think a lot of AHJ's would consider that in violation because they do not see panel [enclosures] as an equipment grounding terminal bus.

 

[luckylerado]

The conductor in question is not an equipment grounding conductor.

Call it what you want. It terminates on the EGC bus and is still sized per 250.122. I suppose calling it a bonding jumper does loosen up the requirement to protect #6 AWG a little bit

250.102(D)

(D) Size ? Equipment Bonding Jumper on Load Side of an
Overcurrent Device. The equipment bonding jumper on the
load side of an overcurrent device(s) shall be sized in accordance
with 250.122.
A single common continuous equipment bonding jumper
shall be permitted to connect two or more raceways or cables if
the bonding jumper is sized in accordance with 250.122 for the
largest overcurrent device supplying circuits therein.

250.102(E)(2)

(2) Outside a Raceway or an Enclosure. If installed on the
outside, the length of the bonding jumper or conductor or equipment
bonding jumper shall not exceed 1.8 m (6 ft) and shall be
routed with the raceway or enclosure.

250.102(E)(3)

(3) Protection. Bonding jumpers or conductors and equipment
bonding jumpers shall be installed in accordance with
250.64(A) and (B).

250.64(B)

(B) Securing and Protection Against Physical Damage.
Where exposed, a grounding electrode conductor or its
enclosure shall be securely fastened to the surface on which it
is carried. Grounding electrode conductors shall be permitted
to be installed on or through framing members. A 4 AWG or
larger copper or aluminum grounding electrode conductor shall
be protected if exposed to physical damage. A 6 AWG grounding
electrode conductor that is free from exposure to physical damage
shall be permitted to be run along the surface of the building
construction without metal covering or protection if it is securely
fastened to the construction; otherwise, it shall be protected in
rigid metal conduit RMC, intermediate metal conduit (IMC),
rigid polyvinyl chloride conduit (PVC), reinforced thermosetting
resin conduit (RTRC), electrical metallic tubing EMT, or cable
armor. Grounding electrode conductors smaller than 6 AWG
shall be protected in (RMC), IMC, PVC, RTRC, (EMT), or cable
armor. Grounding electrode conductors and grounding electrode
bonding jumpers shall not be required to comply with 300.5.

 

[Smart $]

While we're discussing this section, can someone explain why the second sentence is in there? It seems to me that would be covered by the first sentence.

 

[don_resqcapt19]

Call it what you want. It terminates on the EGC bus and is still sized per 250.122. I suppose calling it a bonding jumper does loosen up the requirement to protect #6 AWG a little bit

It is not sized by 250.122. It is sized by the rule in 517.14. The rule only says it must be #10 or larger. It permits, but does not require, sizes larger than #10.

250.102(D)

(D) Size ? Equipment Bonding Jumper on Load Side of an
Overcurrent Device. The equipment bonding jumper on the
load side of an overcurrent device(s) shall be sized in accordance
with 250.122.
A single common continuous equipment bonding jumper
shall be permitted to connect two or more raceways or cables if
the bonding jumper is sized in accordance with 250.122 for the
largest overcurrent device supplying circuits therein.

250.102(E)(2)

(2) Outside a Raceway or an Enclosure. If installed on the
outside, the length of the bonding jumper or conductor or equipment
bonding jumper shall not exceed 1.8 m (6 ft) and shall be
routed with the raceway or enclosure.

250.102(E)(3)

(3) Protection. Bonding jumpers or conductors and equipment
bonding jumpers shall be installed in accordance with
250.64(A) and (B).

250.64(B)

(B) Securing and Protection Against Physical Damage.
Where exposed, a grounding electrode conductor or its
enclosure shall be securely fastened to the surface on which it
is carried. Grounding electrode conductors shall be permitted
to be installed on or through framing members. A 4 AWG or
larger copper or aluminum grounding electrode conductor shall
be protected if exposed to physical damage. A 6 AWG grounding
electrode conductor that is free from exposure to physical damage
shall be permitted to be run along the surface of the building
construction without metal covering or protection if it is securely
fastened to the construction; otherwise, it shall be protected in
rigid metal conduit RMC, intermediate metal conduit (IMC),
rigid polyvinyl chloride conduit (PVC), reinforced thermosetting
resin conduit (RTRC), electrical metallic tubing EMT, or cable
armor. Grounding electrode conductors smaller than 6 AWG
shall be protected in (RMC), IMC, PVC, RTRC, (EMT), or cable
armor. Grounding electrode conductors and grounding electrode
bonding jumpers shall not be required to comply with 300.5.

I don't see any of those sections as applying. If the CMP wanted those sections to apply, they would have called the conductor in question by one of those names. They chose not to do that. The call it an "insulated continuous copper conductor". It is not one of the conductors covered by Article 250. It is a conductor specific to Article 517. There is no requirement to look to other other articles for the installation of this conductor.

 

[Smart $]

Call it what you want. It terminates on the EGC bus and is still sized per 250.122. I suppose calling it a bonding jumper does loosen up the requirement to protect #6 AWG a little bit...

Terminating on the EGC bus does not make it an EGC... or any other Article 250 conductor. Interpretation goes back to 90.3...

Chapters 5, 6, and 7 applyto special occupancies, special equipment, or other special
conditions. These latter chapters supplement or modify the
general rules. Chapters 1 through 4 apply except as amended
by Chapters 5, 6, and 7 for the particular conditions.

...as it is not required in Chapters 1-4, and no section is specifically referenced.

IMO this conductor is not for the purpose of grounding continuity to safely carry any fault current likely to be imposed. I believe that it is rather for reduction of any voltage gradients that may develop on the grounding system at this point as a result of EG separation.

 

[retire09]

It's not a grounding conductor or bond jumper. I see it as an equipotential bond similar to that required for pools. I don't know why 517.14 does not specifically call it that.

 

[luckylerado]

So, we are going to accomplish "Panelboard Bonding" to the Equipment Grounding buss without a bonding jumper or an equipment bonding jumper or equipment grounding conductor and without regard to requirements of Art 250 or looking anywhere except 517.14.

Just duct tape a purple #10 type XF fixture wire between the panel boards.

Good to go.

 

[retire09]

The requirement in 517.14 is in addition to all of the requirements in 250.
This makes for a much safer installation.
Many methods in a healthcare facility are done to a much higher standard.

 

[don_resqcapt19]

So, we are going to accomplish "Panelboard Bonding" to the Equipment Grounding buss without a bonding jumper or an equipment bonding jumper or equipment grounding conductor and without regard to requirements of Art 250 or looking anywhere except 517.14.

Just duct tape a purple #10 type XF fixture wire between the panel boards.

Good to go.

The conductor required by 517.14 has nothing to do with the normal bonding and fault clearing paths.

As Smart said, it is only to make sure there is no difference in potential between the EGCs that serve the circuits in a patient bed vicinity.

 

[retire09]

I would think a lot of AHJ's would consider that in violation because they do not see panel [enclosures] as an equipment grounding terminal bus.

I can see that "as written" connecting the enclosures together is not connecting to the ground bus directly, but I have allowed it. I may be wrong but I feel it meets the intent.

 

[Smart $]

I can see that "as written" connecting the enclosures together is not connecting to the ground bus directly, but I have allowed it. I may be wrong but I feel it meets the intent.

I agree it meets the intent... but I'm sure you've run across others that are overly critical.

 

[retire09]

I agree it meets the intent... but I'm sure you've run across others that are overly critical.

I often find myself all alone outside the box.
I always welcome and enjoy the discussions.