flex bonding

[fireryan]

I have a 2" emt run with a piece of flex in the middle to allow for expansion. Do I need to run a bounding jumper around the flex if I have a EGC installed in the conduit? I can't find a code reference

 

[Dsg319]

I have a 2" emt run with a piece of flex in the middle to allow for expansion. Do I need to run a bounding jumper around the flex if I have a EGC installed in the conduit? I can't find a code reference

Metallic or non-metallic flex?

 

[kwired]

I believe largest overcurrent device protecting the conductors within can be a factor also.

With 2 inch this probably enclosing a feeder or larger branch circuit, but if it contains no more than 20 amp max circuits, then it may not need any bonding jumper.

 

[infinity]

The maximum FMC permitted to serve as an EGC is 1.25" but since you have an EGC within the raceway is a bonding jumper required?

 

[augie47]

In my opinion, even though you have a conductor type grounding conductor, the conduit system is a 250.118 equipmetn ground and jumperrs would need to be installed other than as mentioned by kwired (20 amp circuits)

 

[infinity]

In my opinion, even though you have a conductor type grounding conductor, the conduit system is a 250.118 equipmetn ground and jumperrs would need to be installed other than as mentioned by kwired (20 amp circuits)

The raceway is already bonded at both ends, if the FMC were PVC would it still require a bonding jumper? So the same 2" FMC feeding a transformer with an internal EGC requires an external bonding jumper?

 

[augie47]

The raceway is already bonded at both ends, if the FMC were PVC would it still require a bonding jumper? So the same 2" FMC feeding a transformer with an internal EGC requires an external bonding jumper?

True! I guess if all we are doing is assuring the raceway (conduit) is bonded, no jumper would be needed but IF we wanted to assure the reaceway as a grounding means, albeit, redundant, then a jumper would be needed.
Muddy the water... what if it was a 30 amp branch circuit in a patient care area ??

 

[fireryan]

Metallic or non-metallic flex?

metal

 

[fireryan]

In my opinion, even though you have a conductor type grounding conductor, the conduit system is a 250.118 equipmetn ground and jumperrs would need to be installed other than as mentioned by kwired (20 amp circuits)

I see what you are saying but since the pipe is not being used as the egc than I'm saying you don't need them. I just can't locate a reference. My AHJ agreed with me as well

 

[fireryan]

I believe largest overcurrent device protecting the conductors within can be a factor also.

With 2 inch this probably enclosing a feeder or larger branch circuit, but if it contains no more than 20 amp max circuits, then it may not need any bonding jumper.

yes this is for a 200a feeder. I didn't find anything referencing ocpd

 

[infinity]

I see what you are saying but since the pipe is not being used as the egc than I'm saying you don't need them. I just can't locate a reference. My AHJ agreed with me as well

That's correct. If you use 2" FMC between two junction boxes with an EGC within the FMC you do not also need an external bonding jumper. Same logic applies to the OP.

 

[kwired]

yes this is for a 200a feeder. I didn't find anything referencing ocpd

250.118 covers pretty much everything we talking about here.

1.25 flex is max size permitted to use for EGC, not sure why as it would have even greater cross sectional area, 20 amp ocpd and less, 6 feet of flex or less, and if flexibility is required by the application you still must pull a EGC within.

Pulling EGC within is an internal bonding jumper between the two sides

 

[kwired]

True! I guess if all we are doing is assuring the raceway (conduit) is bonded, no jumper would be needed but IF we wanted to assure the reaceway as a grounding means, albeit, redundant, then a jumper would be needed.
Muddy the water... what if it was a 30 amp branch circuit in a patient care area ??

517.13(A) says the wiring method itself shall qualify as a EGC in accordance with 250.118. If OCPD is over 20 amps FMC doesn't qualify, you can't use FMC for this particular instance at all.

You didn't hardly discolor the water