Old armoured cable with flat metal tape for bond?

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powerplay

Senior Member
In a Commercial install the Plumber changing the Hot Water noticed only the flat "aluminum" tape inside the armoured cable. I had read where it was only to prevent inductive issues during a high fault in the spiral armour and know people fold it back to clamp in the connector. I agreed it isn't a proper Bond for a new Commercial Hot Water Tank, but surprised to read about MC Cable that is intended to save time by cutting it off. O am in Canada and pretty certain it is inadequate as a Bond, as cables do get pulled out of connectors, but was wondering now if it is still made and used?
 

iwire

Moderator
Staff member
Location
Massachusetts
In Canada "AC90" is armoured cable with an copper bond in it that is wrapped clockwise 3/4 ways around the box screw.

Here AC cable will typically only have a bare bonding strip that is cut off or back wrapped around cable, either is acceptable. We can order 'hospital grade' AC that will include a copper EGC. This is for use where the NEC requires redundant grounding. The armor is one ground the copper wire the other.

Than we have type MC cable that also may or may not include a copper grounding wire.
 
In a Commercial install the Plumber changing the Hot Water noticed only the flat "aluminum" tape inside the armoured cable. I had read where it was only to prevent inductive issues during a high fault in the spiral armour and know people fold it back to clamp in the connector. I agreed it isn't a proper Bond for a new Commercial Hot Water Tank, but surprised to read about MC Cable that is intended to save time by cutting it off. O am in Canada and pretty certain it is inadequate as a Bond, as cables do get pulled out of connectors, but was wondering now if it is still made and used?

I would call what you are seeing type AC cable. It is perfectly acceptable per the NEC to use this cable sheath and approved connector as the equipment grounding conductor in most installations. If the cable gets pulled from the connector it is likely due to wrong connector, poor workmanship, and/or improper supporting and securing.

MC cable does not have the bonding strip and has a insulated copper EGC (generally around here).

There are geographic variations as to what is common and used. In upstate NY for example go to pretty much any supply house and ask for AC cable they will have no idea what you are talking about. Describe it and they will think you talking about old BX. Actually the only time in my whole career I have seen AC cable for sale was at a home depot in maryland where I was helping a friend of a friend out for a weekend....
 
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