• We will be performing upgrades on the forums and server over the weekend. The forums may be unavailable multiple times for up to an hour each. Thank you for your patience and understanding as we work to make the forums even better.

Grounding and Bonding requirement for Bollards around utility pole

Merry Christmas

Alim

Member
Location
Canada
Occupation
Engineer
I am looking for a bollard design for utility wood pole protection form heavy traffic area and parking lot.

I am wondering if bollards (steel pipe) around utility pole required to be bonded to the pole ground. I have seen bollard design for padmount transformer, which requires bonding to transformer grounding grid. This is quite understandable and practical; however, I am not sure about the bonding requirement for steel pipe bollard around utility pole. If it is required we can bond the bollard to pole ground, however, it would not be easy specially if we are installing bollards for a existing pole. Does anyone have any experience or comments about this?

I have reviewed one utility bollard design for this application (mechanical protection for pole). They use a PVC pipe around the steel pipe with waterproof PVC end cap at the bottom to isolate it and to prevent the touch potential, however; I am not sure how effective that would be if there is a high level fault occurs near the pole structure. Any comments?
 

tom baker

First Chief Moderator & NEC Expert
Staff member
Location
Bremerton, Washington
Occupation
Master Electrician
Who owns the wood pole?
If you were to ground the bollards what would they be bonded to?
I don’t see any NEC requirement for this.
A simple bollard that is common here is a 6ft x8 in concrete post, with rebar inside

As far as clearance your poco will have requirement
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Consulting Electrical Engineer - Photovoltaic Systems
I am looking for a bollard design for utility wood pole protection form heavy traffic area and parking lot.

I am wondering if bollards (steel pipe) around utility pole required to be bonded to the pole ground. I have seen bollard design for padmount transformer, which requires bonding to transformer grounding grid. This is quite understandable and practical; however, I am not sure about the bonding requirement for steel pipe bollard around utility pole. If it is required we can bond the bollard to pole ground, however, it would not be easy specially if we are installing bollards for a existing pole. Does anyone have any experience or comments about this?

I have reviewed one utility bollard design for this application (mechanical protection for pole). They use a PVC pipe around the steel pipe with waterproof PVC end cap at the bottom to isolate it and to prevent the touch potential, however; I am not sure how effective that would be if there is a high level fault occurs near the pole structure. Any comments?
How would such a bollard become energized relative to the earth it is set in if it were not bonded?
 
How would such a bollard become energized relative to the earth it is set in if it were not bonded?
Exactly. And clearly a significant percentage of people are obsessed with grounding and bonding, but I say bonding sometimes increases the risks. Think about open neutrals, potentials during faults, etc. Connecting something to an electrical system is not universally a good thing.
 

hornetd

Senior Member
Location
Maryland
Occupation
Journeyman Electrician, Retired
I am looking for a bollard design for utility wood pole protection form heavy traffic area and parking lot.

I am wondering if bollards (steel pipe) around utility pole required to be bonded to the pole ground. I have seen bollard design for padmount transformer, which requires bonding to transformer grounding grid. This is quite understandable and practical; however, I am not sure about the bonding requirement for steel pipe bollard around utility pole. If it is required we can bond the bollard to pole ground, however, it would not be easy specially if we are installing bollards for a existing pole. Does anyone have any experience or comments about this?

I have reviewed one utility bollard design for this application (mechanical protection for pole). They use a PVC pipe around the steel pipe with waterproof PVC end cap at the bottom to isolate it and to prevent the touch potential, however; I am not sure how effective that would be if there is a high level fault occurs near the pole structure. Any comments?
I know this will illicit some howls but I feel I should point out that putting a non yielding barrier around utility poles is very likely to protect the pole but also likely to kill some folk.
If you actually want to protect the pole then:
  • coat it in waterproofing compound, install a plastic cylinder around it that is double walled,
  • fill the inner cylinder with sand and the outer cylinder with water that has been mixed with an environmentally non destructive antifreeze,
  • place a raintite cover over the top.

When struck at a moderate speed the water would be displaced into a bladder lying on top of the assembly absorbing much of the force in the process. If struck at a higher speed the sand would continue absorbing force and the occupants of the vehicle would be less likely to be killed. Plus the protection from the impact would lessen the conductor whipping that occurs during vehicular pole strikes and reduce the number of power outages and deaths arising from wires down on the vehicle.

Oh my God it's the NANNY STATE!
"Let them die then and decrease the surplus population." (Ebeneezer Scrooge. A character from the book "A Christmas Carrol" by Charles Dickens.

Procedure for extrication of trapped occupants of a vehicle energized by a power line in contact with the vehicle.

Throw the PEPCO [Potomac Electric Power Company (Now an Excelon subsidiary)] rope over the downed line. [PEPCO Rope: a polypropylene rope with a short bar fastened to the end having a pike pole hooking loop at each end of the bar at 90° to each other.] Hook one of the opposing rings with a CLEAN pike pole, drag the thrown end of the PEPCO rope under the downed wire. Drag the downed wire off of the vehicle. If possible draw the downed wire into hard contact with a good electrical ground, such as a manhole cover or fire hydrant, to fully fault out the line. Once the line has been reenergized by it's recloser 3 times it will remain deenergized unless deliberately reset by remote control. Once the downed wire is clear of the vehicle commence rescue and medical care on the vehicle's occupants.

Tom Horne
 

Alim

Member
Location
Canada
Occupation
Engineer
Who owns the wood pole?
If you were to ground the bollards what would they be bonded to?
I don’t see any NEC requirement for this.
A simple bollard that is common here is a 6ft x8 in concrete post, with rebar inside

As far as clearance your poco will have requirement
same company who is going to install the bollards.
Bonded to pole ground. Each pole has pole butt ground coil.
The bollard design we have is similar to what you described except the above ground part which is exposed steel rod.
 

Alim

Member
Location
Canada
Occupation
Engineer
Exactly. And clearly a significant percentage of people are obsessed with grounding and bonding, but I say bonding sometimes increases the risks. Think about open neutrals, potentials during faults, etc. Connecting something to an electrical system is not universally a good thing.
How would such a bollard become energized relative to the earth it is set in if it were not bonded?
The bollards may be installed near a pole which have pole mounted transformers installed (a source, fault return destination), so the theory is if there is a fault happens downstream and at the same time if someone is touching the steel part of the bollard, then the person may get touch potential.
 
The bollards may be installed near a pole which have pole mounted transformers installed (a source, fault return destination), so the theory is if there is a fault happens downstream and at the same time if someone is touching the steel part of the bollard, then the person may get touch potential.
I still say bonding to the MGN creates more risks in this case. You can't really Bond your way out of touch and step potential, you would really need an equipotential grid under the whole area. Perhaps bonding all the bollards together but not to the MGM would be the best?
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
The bollards may be installed near a pole which have pole mounted transformers installed (a source, fault return destination), so the theory is if there is a fault happens downstream and at the same time if someone is touching the steel part of the bollard, then the person may get touch potential.
Who came up with that theory?

It seems to be that what is going on here is someone came up with a plan to solve one mostly nonexistent problem and others came up with why the solution is a problem. Best answer is maybe to have not put the poles where they are in so hazardous of a condition. Bury the wires. Poles are gone. Problem solved.
 
Top