powerplay
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If armoured cable is run into an Pole light with a bond screw, does the cable in the pole require a connector to be bonded to an enclosure if already bonded from it's source?
Bonding Cable Sheath
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kwired
Electron manager
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Are you talking about type "AC cable"?
If so the sheath is the equipment grounding conductor and it pretty much needs to have a fitting on the end of the cable to bond to the enclosure it attaches to. In the somewhat rare case of not installing a fitting into an enclosure I suppose it may be acceptable to still put a connector on end of cable and install a grounding busing on the fitting so you can put a bonding jumper from there to wherever necessary.
Next question, if I understand correctly, is what circumstances do you have where running AC cable to a light pole is acceptable? Most instances it probably wouldn't be allowed because the pole is in a damp or wet location as well as methods required to get to the pole.
If so the sheath is the equipment grounding conductor and it pretty much needs to have a fitting on the end of the cable to bond to the enclosure it attaches to. In the somewhat rare case of not installing a fitting into an enclosure I suppose it may be acceptable to still put a connector on end of cable and install a grounding busing on the fitting so you can put a bonding jumper from there to wherever necessary.
Next question, if I understand correctly, is what circumstances do you have where running AC cable to a light pole is acceptable? Most instances it probably wouldn't be allowed because the pole is in a damp or wet location as well as methods required to get to the pole.
powerplay
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The Cable is actually "Teck" with the rubber jacket on armour sheath.
I'm in Canada (eh), and AC90 up here has a bare copper bond wire inside the sheath, but in this case the Teck also has the bare copper bond which was attached to the Wharf Light Post by means of an Lug. The Conductors in this Teck have an "RW" wet location rating. I have used an bonding bushing in the past to ensure the sheath is bonded on both sides, but although I recall being told the sheath should be bonded both sides it sounds like bonding one end complies with safety requirements?
TEK isn't an NEC recognized cable type, but FWIW there are no cable types I'm aware of that don't require a connector of some sort at each end. :happyyes:
I believe the sheath must be bonded at both ends as a matter of continuity of the grounding path. Others may debate that bonding one end complies, but I say "path" implies "through" rather than just "from" or "to".
I believe the sheath must be bonded at both ends as a matter of continuity of the grounding path. Others may debate that bonding one end complies, but I say "path" implies "through" rather than just "from" or "to".
kwired
Electron manager
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- NE Nebraska
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- EC
If the sheath is the equipment grounding conductor (like it is with AC cable) then you have to bond to each end in order to extend the EGC to your equipment. Generally this is done by using proper fitting and installing it into a hole (KO) in the metallic enclosure being supplied. In the absence of a KO to mount the fitting into you need to get more creative - like maybe at least a bonding bushing on the fitting should you find some situation where you don't have a KO to land the fitting into.
powerplay
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The CSA reference is TECK90 which are Copper conductors in direct burial armored cable, and ACWU90 for aluminum in direct burial cable with armor.
In this installation, TECK90 is stubbed up into the Light Post and strapped from below. The armored sheath is bonded at the source, but the installer felt a connector and bonding bushing were not necessary, as the bare bond conductor inside was connected to an Lug inside the Post.
Interesting install was the Teck90 Service Cable that had the bare bond wire cut off at the Utility's connection end since it was inside of an PVC Weather head as an Inspector suggested, and apparently done in Industrial applications. I had thought the bare bond would be wrapped around the sheath... but would that cause sheath currents from bare conductor to the sheath?
The bare grounding conductor within the cable is not in contact with the armor sheath. Thus bonding of the sheath relies on using a connector at each end.
I do not know whether CEC requires pass-through bonding or just dead-end bonding, but as I said earlier, all cables require a connector at each end.
kwired
Electron manager
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- NE Nebraska
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- EC
Is this bare bond conductor a supplemental component designed to improve resistance of the sheath or is it a stand alone equipment grounding conductor? If it is there to improve resistance of the sheath then the bond wire plus the sheath together are the equipment grounding conductor - at least in a NEC covered AC or MC cable.
powerplay
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The bare Copper inside the Cable Jacket is surrounded by a rubber Jacket in TECK90, and serves as the Equipment Bond. In an Service Cable installation, the Inspector had advised to cut it off at the Utility connection point because it was already Bonded at the Service Switch by a Ground Bushing. (This is why I was curious) The Sheath is protection against mechanical damage and not permitted to be used as a Bond for Equipment as it can spiral off from the connector in some cases. the 2 screw Connector is the proper connector for larger TECK90 cables because it compresses oval like, and has grooves with more surface area to hold the cable in place. It sounds like Bonding it ensures that damaged armor will trip the breaker, but not permitted to be the Equipment Bond up here
powerplay
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May I ask what you mean by "pass through bonding"? I recall being told bonding is to be done on both ends of the Cable in school, but was searching for our CEC code reference to it. Is it an NEC requirement to bond both ends because it is your bonding for all cables?
Pass-through bonding is my terminology. It simply means a long conductive item such as sheathing or conduit is bonded on both ends so ground fault current originating at any location can pass through it. The contrary position is dead-end bonding, or bonding one end. Ground fault current from any external source may not pass through this conductive item if it is only bonded at one end.
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