Equipment Grounding Conductor

[Bill Snyder]

I was asked this question by a student: When any part of 250.118 references the wiring method as sufficient to be used as an equipment grounding conductor, does that include the fittings?

 

[electrofelon]

I was asked this question by a student: When any part of 250.118 references the wiring method as sufficient to be used as an equipment grounding conductor, does that include the fittings?

The fittings for Some/many of the raceways in 250.118 are required to be listed, and the ones that are not require fitting be listed in their respective articles i.e EMT and RMC....so perhaps being evaluated for grounding is part of the listing? Or maybe it's just assumed that fittings fall under a raceway listed in 250.118. So short answer I'm not sure which one it is

 

[MTW]

Depends on the raceway type and the fittings used. They need to be listed as grounding or may have limitations or restrictions to ampacity of the contained circuits or length of the conduit used.

Partial quote:

250.118 Types of Equipment Grounding Conductors. The
equipment grounding conductor run with or enclosing the
circuit conductors shall be one or more or a combination of
the following:
(1) A copper, aluminum, or copper-clad aluminum conductor.
This conductor shall be solid or stranded; insulated,
covered, or bare; and in the form of a wire or a busbar of
any shape.
(2) Rigid metal conduit.
(3) Intermediate metal conduit.
(4) Electrical metallic tubing.
(5) Listed flexible metal conduit meeting all the following
conditions:
a. The conduit is terminated in listed fittings.
b. The circuit conductors contained in the conduit are
protected by overcurrent devices rated at 20 amperes
or less.

d. The combined length of flexible metal conduit and
flexible metallic tubing and liquidtight flexible metal
conduit in the same ground-fault current path does
not exceed 1.8 m (6 ft).
e. If used to connect equipment where flexibility is
necessary to minimize the transmission of vibration
from equipment or to provide flexibility for equipment
that requires movement after installation, an
equipment grounding conductor shall be installed.
(6) Listed liquidtight flexible metal conduit meeting all the
following conditions:
a. The conduit is terminated in listed fittings.
b. For metric designators 12 through 16 (trade sizes
3∕8 through 1∕2), the circuit conductors contained in
the conduit are protected by overcurrent devices
rated at 20 amperes or less.
c. For metric designators 21 through 35 (trade sizes
3∕4 through 11∕4), the circuit conductors contained in
the conduit are protected by overcurrent devices
rated not more than 60 amperes and there is no flexible
metal conduit, flexible metallic tubing, or liquidtight
flexible metal conduit in trade sizes metric
designators 12 through 16 (trade sizes 3∕8 through 1∕2)
in the ground-fault current path.
d. The combined length of flexible metal conduit and
flexible metallic tubing and liquidtight flexible metal
conduit in the same ground-fault current path does
not exceed 1.8 m (6 ft)

 

[electrofelon]

They need to be listed as grounding

In what cases is that? I didn't see anything in 118 saying a fitting must be listed as grounding for use as an EGC

 

[infinity]

In what cases is that? I didn't see anything in 118 saying a fitting must be listed as grounding for use as an EGC

I'm no UL guy but I'm pretty sure that all metal raceway fittings are listed for the grounding of the raceway it's attached to.

 

[electrofelon]

I'm no UL guy but I'm pretty sure that all metal raceway fittings are listed for the grounding of the raceway it's attached to.

Yeah I think so too. I doubt there is a fitting you would not be able to use of you were using the raceway as an EGC

 

[NoahsArc]

I'm no UL guy but I'm pretty sure that all metal raceway fittings are listed for the grounding of the raceway it's attached to.

At least, I would not expect a supply house to carry on that was so limited. Who would install them?

 

[don_resqcapt19]

The UL Guide Information for Conduit Fittings (DWTT), says that all listed fittings for metal cable and metal conduit and tubing are suitable for providing the equipment grounding path. It shows the listing fittings for flexible metal raceways as having the same restrictions as shown in 250.118.