MC cable outside

D

dm9289

Industrial Maintenance Electrician
Location
Pennsylvania
Occupation
Industrial process repair/ maintenance Electrician
This MC cable is in a breeze way see picture. Please ignore the large unsealed hole. The roof in theory does not leak, both ends of breezeway are always open with no climate control.
I think this is a damp location and not code compliant. Other opinions welcome
 

Attachments

  • IMG_8392.jpeg
    IMG_8392.jpeg
    348.1 KB · Views: 40
dm9289 said:
This MC cable is in a breeze way see picture. Please ignore the large unsealed hole. The roof in theory does not leak, both ends of breezeway are always open with no climate control.
I think this is a damp location and not code compliant. Other opinions welcome
Click to expand...
See 330.10(11) There are various means for MC to b acceptable in a damp location,.
 
augie47 said:
See 330.10(11) There are various means for MC to b acceptable in a damp location,.
Click to expand...
It had no special outer jacket or fittings. It appeared what I would generally see indoors.
 
Look at the definitions in Article 100. This is not a wet location so what would prohibit its use in a damp location?

Part II. Installation
330.10 Uses Permitted. 330.10(A) General Uses.
Type MC cable shall be permitted as follows:
(1) For services, feeders, and branch circuits.
(2) For power, lighting, control, and signal circuits.
(3) Indoors or outdoors.
(4)Exposed or concealed.
(5)To be direct buried where identified for such use.
(6)In cable tray where identified for such use.
(7)In any raceway.
(8)As aerial cable on a messenger.
(9)In hazardous (classified) locations where specifically permitted by other articles in this Code.
(10)In dry locations and embedded in plaster finish on brick or other masonry except in damp or wet locations.
(11)In wet locations where a corrosion-resistant jacket is provided over the metallic covering and any of the following conditions are met:
a. The metallic covering is impervious to moisture.
b. A jacket resistant to moisture is provided under the metal covering.
c. The insulated conductors under the metallic covering are listed for use in wet locations.
(12)Where single-conductor cables are used, all phase conductors and, where used, the grounded conductor shall be grouped together to minimize induced voltage on the sheath.
Click to expand...
 
I see 330.12(2)(b) as a potential issue. If this is the typical MC Lite being readily sold and being AL sheathing, laying flat contact onto concrete block will readily corrode. Seen it to the extent, after a very few number of years, being completely gone.
 
I don't how Al MC cable will corrode if in contact with concrete block unless it's in a corrosive environment. Is there something in the photo that would indicate that this is a corrosive environment?
 
infinity said:
I don't how Al MC cable will corrode if in contact with concrete block unless it's in a corrosive environment. Is there something in the photo that would indicate that this is a corrosive environment?
Click to expand...

I thought aluminum corrodes when in contact with concrete. That was the reason for 250.64(A)(1).

"Bare or covered conductors without an extruded polymeric covering shall not be installed where subject to corrosive conditions or be installed in direct contact with concrete."

I guess I don't know if there is a difference between a concrete block or poured cement footing when considering the effects of corrosion. Though it could have more to do with the aluminum mixture than the actual concrete.

But now that I think about it, I have seen aluminum EMT strapped to cement walls in new builds before. 358.10 has different wording. They specify encased. Not just touching.
 
infinity said:
I don't how Al MC cable will corrode if in contact with concrete block unless it's in a corrosive environment. Is there something in the photo that would indicate that this is a corrosive environment?
Click to expand...
All I know the several instances I seen, not any corrosive environment beyond just contact with the concrete wall and blocks. Every point of contact corroded to nothing, the parts that were not touching had no corrosion.
 
infinity said:
I don't how Al MC cable will corrode if in contact with concrete block unless it's in a corrosive environment. Is there something in the photo that would indicate that this is a corrosive environment?
Click to expand...
No it’s a galvanizing plant and that breezeway is outside the building
 
infinity said:
Look at the definitions in Article 100. This is not a wet location so what would prohibit its use in a damp location?
Click to expand...
Thank you I noticed provisions for dry and wet but not damp.
Southwire site seemed a little vague also
 
infinity said:
Look at the definitions in Article 100. This is not a wet location so what would prohibit its use in a damp location?
Click to expand...
I work in the steel process and this install was done by HVAC contractors. Going thru the breezeway it caught my eye. I immediately thought not code compliant.

After reading the MC article I was not so sure. Figured a good learning experience for me.
 
Fred B said:
All I know the several instances I seen, not any corrosive environment beyond just contact with the concrete wall and blocks. Every point of contact corroded to nothing, the parts that were not touching had no corrosion.
Click to expand...
Here is Southwires reply about contact.
IMG_8408.jpeg
 
dm9289 said:
It took me a while to get an answer from south wire but here it is. No good for damp location
Click to expand...
I don't think that their response is accurate. From their own specifications it say nothing about only dry locations. MC cable is permitted in damp locations. One would also think that if it can be embedded in plaster which can be corrosive when wet it can certainly be in contact with concrete.
MC-AP Type MC All Purpose
14 AWG through 8 AWG Copper THHN Insulated Conductors. Full-Sized Aluminum Equipment Grounding/Bonding
Conductor. UL Listed. 600 Volt. Rated VW1. Lightweight Aluminum Interlocked Armor is Part of Equipment
Bonding/Grounding Path.
Southwire MCAP Type MC Cable - All Purpose is suitable for use as follows:
• Wherever standard AC or MC Cable is permitted.
• Branch circuit wiring in commercial, industrial, institutional, and multi-residential
buildings.
• Fished or embedded in plaster.
• Concealed or exposed installations.
• Environmental air-handling spaces per NEC 300.22 (C).
• Places of Assembly per NEC 518.4 and theaters per NEC 520.5.
• Installation in cable tray and approved raceways.
• Under raised floors for information technology equipment conductors and cables per
NEC 645.5(D) & 645.5(D)(2).
• Use UL Lised Type MCI-A connectors
Click to expand...
 
dm9289 said:
Here is Southwires reply about contact.
View attachment 2574819
Click to expand...
If a typical basement is considered a damp location per code we better reconsider any product listed for dry space only if installing in a basement. But Only issue witnessed was related to MC lite (AL) in direct contact with the concrete, but not in open air or even in contact with other materials including some rotted damp wood, within same basement. It seemed only corroded when touching the concrete.
 
Fred B said:
If a typical basement is considered a damp location per code we better reconsider any product listed for dry space only if installing in a basement. But Only issue witnessed was related to MC lite (AL) in direct contact with the concrete, but not in open air or even in contact with other materials including some rotted damp wood, within same basement. It seemed only corroded when touching the concrete.
Click to expand...
The application I have is outdoors. Subject to condensation in my opinion. Cold outside breezeway between 2 warm buildings.
 
You must log in or register to reply here.
Top