Required Vehicle Clearance Distance from Substation Fence and Relevant Code References

[Golden State EE]

I am seeking clarification on the required clearance distance for vehicles, such as golf carts, maintenance trucks, and other equipment, from a substation fence. Specifically, I would like to know:

1. What is the minimum distance vehicles should be kept from the substation fence to ensure safety and compliance with regulations?
2. Are there distinctions based on the type of vehicle (e.g., light vehicles like golf carts versus larger trucks) or the voltage level of the substation?
3. Which sections of applicable codes or standards, such as the NESC, NEC or local utility regulations, provide specific guidance on this matter?
4. If anyone has experience or insights on this topic, including code references or best practices, I’d greatly appreciate your input! Thank you!

 

[LittleInch]

I'll confess I don't know exactly, but the general rule is that someone can do anything they like, within reason, on the other side of your fence as you have no powers or ability to stop them unless you own the land. The same applies to gas reception facilities - the hazardous area classifications need to be within the fenceline as there is very little you can do to stop anyone having a cigarette or a BBQ right against your fence if you don't own the land. Maybe not a great plan, but there are limts to the powers given to utility companies.

So basically make sure your fence is far enough away to prevent any issues.

You see substations right on the edge of busy main roads so I doubt you find what you're looking for in terms of regulations.

Guidance is a different thing and risks which are location dependant. So some might need vehicle barriers ( on your land) as added protection, but many won't.

Why are you asking?

 

[BeckettHale]

Thank you so much for the info.

 

[JJ_Roy]

There is no requirement that I'm aware of regarding the minimum distance for vehicles from a substation fence. The fence should meet NESC Rule 110 to maintain clearance for unauthorized persons.

If your substation lives in "NERC land", then it may be subject to the NERC Physical Security requirements. This may include physical threats from vehicles as part of the security assessment.

I don't know your exact situation but you may also want to apply some common sense to the issue if vehicle traffic is a potential risk. We had a couple of small substations that were on the edge of parking lots or subject to nearby vehicle traffic that we installed bollards or guardrails to protect from vehicles. The biggest issue was that the fence would get all messed up from cars crashing into it, which would always happen on a Saturday night on a holiday weekend! There was always an issue finding a fence contractor to come out and fix the fence in an emergency so we'd have to post a guard until the fence was fixed.

 

[bacon4life]

No specific regulations that I know of that world require a specific clearance. Comment sense would be maintaining enough clearance to avoid inadvertently damaging the fence and/or vehicle.

In the 3-6 foot zone outside the a substation fence there is typically an area of risk for touch and/or step potential. Substation fences are often set 3-6 feet inside the property line so that the touch/step potential hazard can be managed by installing crushed rock and a substation ground grid outside the fence line.