Manholes used as UFER grounds

[John Adams]

First off, I used the non-politically correct word in the title. Today I have to say Maintenance Holes............sorry
In my opinion, a MH clearly qualifies as a UFER ground per the definition of a UFER ground. I've been to the plant where the MHs are made and it sure seems they qualify as a GREAT source of ground. The US military has finally agreed to my opinion so most new MHs will be required to be integrated grounding system MHs. In my opinion, not only is it less expensive to install (no need for multiple grounds in the MH, no need for halos in the MH, but it is a GREAT ground that only gets better over time due to the lime enhancing the soil over time
BUT, just my opinion.......................yours?
thanks

 

[tom baker]

What is the purpose of the ground in a manhole?
Is the ufer replacing a ground rod?
What is voltage of conductors in the MH?

 

[John Adams]

Hey Tom
he purpose of the ground source in the MH is to bond the internal of external metallic sheaths of the cables when splices are required in the MH. For MANY years (and I go back 54 years in the telecomm world) we'd place a new MH and we would always place a 5 ft x 1/2" copper rod in the corner of the MH. Then we'd use a #6 from that rod to either a busbar or to the metallic cable racks within the MH
. By using a integrated grounded MH, the manufacturer tack welds a heavy metallic strap in multiple places in the "shell" of the MH before pouring the concrete which creates the top or bottom half of the MH
hope that helps Tom

 

[roger]

But what are these ground rods or CEE's supposed to do? What voltages are we looking at?

 

[don_resqcapt19]

I see no reason for any type of grounding electrode at a manhole for any power system.

 

[John Adams]

But what are these ground rods or CEE's supposed to do? What voltages are we looking at?

Roger
These MHs are only for telecomm MHs (non permit required confined spaces)
hope that helps

 

[John Adams]

I see no reason for any type of grounding electrode at a manhole for any power system.

Don
These MHs are for telecomm.....non-permit required confined spaces
Hope that helps

 

[don_resqcapt19]

Don
These MHs are for telecomm.....non-permit required confined spaces
Hope that helps

No idea about telecom as I don't do that type of work.
What function would the addition connection to earth at a manhole for a telecom system serve?

 

[hbiss]

I don't know offhand what the Bell requirements are for grounding and bonding OSP buried plant and I can't remember the last time I was down in a manhole or vault or CEV but I would think that if you had access to the rebar I would certainly ground to it.

What function would the addition connection to earth at a manhole for a telecom system serve?

Similar to the grounds at poles and transformer pads.

-Hal

 

[tom baker]

If you can use the MH rebar as a UFER ground go for it. If this is telecom it is more likely a Bell System spec, related to lightning protection.
some of us were questioning the reason why as we see ground rods used with no benefit

 

[John Adams]

If you can use the MH rebar as a UFER ground go for it. If this is telecom it is more likely a Bell System spec, related to lightning protection.
some of us were questioning the reason why as we see ground rods used with no benefit

In my case it was a General Telephone, (GTE/Verizon) spec. Way back when we called them GTEP (GTE Practices) which were very similar to Bell System Practices (BSP I think they were called).

 

[tom baker]

Bell would have a good reason for grounding based on 1,000s of MH. Lightning or hv line damaging phone cable

 

[hbiss]

I believe the BSPs came first, GTE based theirs on them.

-Hal