Data Ground Bar Ground Choke

[Hobgoblin66]

We have a project where ground conductors are being run from various data center ground bars to a central location for grounding reference. These grounds are not meant for fault current, only reference points. The electrician that installed these ground cables ran them through ferrous sleeves without bonding at either end. Is this a code issue? I don't believe that 250.64 applies as this is not used for fault current. Please correct me if I'm wrong.

 

[ron]

Generally a requirement found in the specification. Not a code issue since these are supplemental.

 

[luckylerado]

If it is a data center built to industry standards, it is very likely subject to the requirements of TIA and would require a bonding bushing on both sides of the ferrous raceway 3' or greater in length and bonded with a min #6 awg copper.


J-STD-607-A
5.1.4 "Grounding and bonding conductors should not be placed in ferrous metallic
conduit. If it is necessary to place grounding and bonding conductors in ferrous metallic
conduit that exceeds 1 m (3 ft) in length, the conductors shall be bonded to each end of
the conduit using a grounding bushing or a NO. 6 AWG conductor, minimum."

 

[Sahib]

We have a project where ground conductors are being run from various data center ground bars to a central location for grounding reference. These grounds are not meant for fault current, only reference points. The electrician that installed these ground cables ran them through ferrous sleeves without bonding at either end. Is this a code issue? I don't believe that 250.64 applies as this is not used for fault current. Please correct me if I'm wrong.

If any high frequency signal current is passing through those ground conductors, non-bonding the ferrous sleeves could lead to signal attenuation. So check with relevant technical specifications.

 

[ron]

If it is a data center built to industry standards, it is very likely subject to the requirements of TIA and would require a bonding bushing on both sides of the ferrous raceway 3' or greater in length and bonded with a min #6 awg copper.


J-STD-607-A
5.1.4 "Grounding and bonding conductors should not be placed in ferrous metallic
conduit. If it is necessary to place grounding and bonding conductors in ferrous metallic
conduit that exceeds 1 m (3 ft) in length, the conductors shall be bonded to each end of
the conduit using a grounding bushing or a NO. 6 AWG conductor, minimum."

Although this ANSI standard is a great resource, just note that it is not a code requirement.

 

[MBLES]

We have a project where ground conductors are being run from various data center ground bars to a central location for grounding reference. These grounds are not meant for fault current, only reference points. The electrician that installed these ground cables ran them through ferrous sleeves without bonding at either end. Is this a code issue? I don't believe that 250.64 applies as this is not used for fault current. Please correct me if I'm wrong.

Communications standards like this are found in IEEE. I was getting inspection on electrical and the inspector wouldnt even look at the communication side of work. He said we dont look at 50v or less or 50w of less. i have found that Article 800 does apply but only to people who care.

we service alot of DC power equipment and once during a copper theft they cut the negative side of a battery string that hit the air condition vent and now the AC unit was carrying the 175a back to the Electrical panel threw the #12 ground. needless to say it melted the wiring going to unit because it finally melter apart. I think DC when ran next to electrical needs to be one inspection. Just saying.