MC cable pulled into EMT

[herding_cats]

I've got some new guys at my jobsite that are pulling MC cable into EMT above the drop ceiling without bonding with a 4 square box. What codes are being broken here exactly? They claim it does not violate any codes. It's one of those deals they claim that NEC "doesn't" say you "can't" do it.

 

[wwhitney]

2017 NEC 250.96(A) says "Metal raceways, cable trays, cable armor, cable sheath, enclosures, frames, fittings, and other metal non–
current-carrying parts that are to serve as equipment grounding conductors, with or without the use of supplementary equipment grounding conductors, shall be bonded where necessary to ensure electrical continuity and the capacity to conduct safely any fault current likely to be imposed on them."

Cheers, Wayne

 

[ModbusMan]

How do they intend to properly secure both the MC and EMT to the j-box's knock-out correctly and simultaneously, given that the connectors of the two types are quite different and will physically exclude each other?

 

[CoolWill]

Is the MC just passing through an EMT sleeve, or are they sticking MC in a conduit that terminates in a box?

 

[letgomywago]

They make a special transition connector

 

[herding_cats]

Is the MC just passing through an EMT sleeve, or are they sticking MC in a conduit that terminates in a box?

yes they are sliding MC into EMT and not bonding.

 

[herding_cats]

Thanks for responses. Cheers

 

[herding_cats]

Is the MC just passing through an EMT sleeve, or are they sticking MC in a conduit that terminates in a box?

yes

2017 NEC 250.96(A) says "Metal raceways, cable trays, cable armor, cable sheath, enclosures, frames, fittings, and other metal non–
current-carrying parts that are to serve as equipment grounding conductors, with or without the use of supplementary equipment grounding conductors, shall be bonded where necessary to ensure electrical continuity and the capacity to conduct safely any fault current likely to be imposed on them."

Cheers, Wayne

Yup

 

[curt swartz]

yes they are sliding MC into EMT and not bonding.

You did really answer CoolWill's question.
Is the MC just passed through a section of EMT as a sleeve OR does the EMT terminate into a box?

 

[jmellc]

Proper way to do that would be strip MC back to where EMT begins & use a changeover fitting. Bare conductors from there to the box & ground to the box. I've done that for stub ups to ceiling from switchboxes & occasionally to a short stub from a lighting box.

 

[LarryFine]

 

[herding_cats]

Proper way to do that would be strip MC back to where EMT begins & use a changeover fitting. Bare conductors from there to the box & ground to the box. I've done that for stub ups to ceiling from switchboxes & occasionally to a short stub from a lighting box.

exactly that's what I showed them. They did it their way anyway. It's not technically bonded.

 

[herding_cats]

You did really answer CoolWill's question.
Is the MC just passed through a section of EMT as a sleeve OR does the EMT terminate into a box?

no they are just sliding MC into EMT and landing the 4-square box on the EMT. The MC is just "floating" inside EMT.

 

[LarryFine]

It does make for a great expansion joint.

 

[herding_cats]

yeah I guess it would. I want to author a coffee table book of photos where the PVC has pulled out of meter bases and panels, boxes where someone cheap-skated the non-use of an expansion joint. It drives me nuts seeing these at strip malls and cheap McMansion homes.

 

[roger]

How do they intend to properly secure both the MC and EMT to the j-box's knock-out correctly and simultaneously, given that the connectors of the two types are quite different and will physically exclude each other?

When the EMT is a complete system the MC is simply conductors installed inside it and does not need individual securing, see 330.10(7) and 358.22.

 

[CoolWill]

When the EMT is a complete system the MC is simply conductors installed inside it and does not need individual securing, see 330.10(7) and 358.22.

I don't think the EMT is complete. I think MC is coming into the raw end of an EMT and then coming out in a box. There is no fitting attaching the MC to the EMT.

 

[winnie]

2017 NEC 250.96(A) says "Metal raceways, cable trays, cable armor, cable sheath, enclosures, frames, fittings, and other metal non–
current-carrying parts that are to serve as equipment grounding conductors, with or without the use of supplementary equipment grounding conductors, shall be bonded where

For normal MC cable, the armor does not serve as the equipment grounding conductor.

The problems that I have either the installation as described by the OP are:
How are the conductors protected from the armor without an MC connector at the end point?

If this is MC-AP, how is the EGC bonded?

Is there anything providing strain relief on the terminations in the box if the MC gets tugged.